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Sample records for advanced optical microscopy

  1. Advanced Motion Compensation Methods for Intravital Optical Microscopy

    PubMed Central

    Vinegoni, Claudio; Lee, Sungon; Feruglio, Paolo Fumene; Weissleder, Ralph

    2013-01-01

    Intravital microscopy has emerged in the recent decade as an indispensible imaging modality for the study of the micro-dynamics of biological processes in live animals. Technical advancements in imaging techniques and hardware components, combined with the development of novel targeted probes and new mice models, have enabled us to address long-standing questions in several biology areas such as oncology, cell biology, immunology and neuroscience. As the instrument resolution has increased, physiological motion activities have become a major obstacle that prevents imaging live animals at resolutions analogue to the ones obtained in vitro. Motion compensation techniques aim at reducing this gap and can effectively increase the in vivo resolution. This paper provides a technical review of some of the latest developments in motion compensation methods, providing organ specific solutions. PMID:24273405

  2. What advances in microscopy are required for combined MRI and optical functional brain imaging? (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kleinfeld, David

    2016-03-01

    This overview talk will focus on forward-looking scientific needs and physical limits to images of neuronal processes. The challenge in nervous systems is that the basic unit for "switching" events in the nervous system occurs on the one micrometer scale of synaptic spines, while computations involve communication between individual neurons across the full expanse of cortex, which is ten millimeters for mouse cortex. I will address hoped-for advances in optical microscopy, within the context of existing and proposed contrast mechanisms of neuronal function, that span the four orders of magnitude of length scales for neuronal processing

  3. In situ observation of elementary growth processes of protein crystals by advanced optical microscopy.

    PubMed

    Sazaki, Gen; Van Driessche, Alexander E S; Dai, Guoliang; Okada, Masashi; Matsui, Takuro; Otálora, Fermin; Tsukamoto, Katsuo; Nakajima, Kazuo

    2012-07-01

    To start systematically investigating the quality improvement of protein crystals, the elementary growth processes of protein crystals must be first clarified comprehensively. Atomic force microscopy (AFM) has made a tremendous contribution toward elucidating the elementary growth processes of protein crystals and has confirmed that protein crystals grow layer by layer utilizing kinks on steps, as in the case of inorganic and low-molecular-weight compound crystals. However, the scanning of the AFM cantilever greatly disturbs the concentration distribution and solution flow in the vicinity of growing protein crystals. AFM also cannot visualize the dynamic behavior of mobile solute and impurity molecules on protein crystal surfaces. To compensate for these disadvantages of AFM, in situ observation by two types of advanced optical microscopy has been recently performed. To observe the elementary steps of protein crystals noninvasively, laser confocal microscopy combined with differential interference contrast microscopy (LCM-DIM) was developed. To visualize individual mobile protein molecules, total internal reflection fluorescent (TIRF) microscopy, which is widely used in the field of biological physics, was applied to the visualization of protein crystal surfaces. In this review, recent progress in the noninvasive in situ observation of elementary steps and individual mobile protein molecules on protein crystal surfaces is outlined.

  4. The development of optical microscopy techniques for the advancement of single-particle studies

    SciTech Connect

    Marchuk, Kyle

    2013-05-15

    Single particle orientation and rotational tracking (SPORT) has recently become a powerful optical microscopy tool that can expose many molecular motions. Unfortunately, there is not yet a single microscopy technique that can decipher all particle motions in all environmental conditions, thus there are limitations to current technologies. Within, the two powerful microscopy tools of total internal reflection and interferometry are advanced to determine the position, orientation, and optical properties of metallic nanoparticles in a variety of environments. Total internal reflection is an optical phenomenon that has been applied to microscopy to produce either fluorescent or scattered light. The non-invasive far-field imaging technique is coupled with a near-field illumination scheme that allows for better axial resolution than confocal microscopy and epi-fluorescence microscopy. By controlling the incident illumination angle using total internal reflection fluorescence (TIRF) microscopy, a new type of imaging probe called “non-blinking” quantum dots (NBQDs) were super-localized in the axial direction to sub-10-nm precision. These particles were also used to study the rotational motion of microtubules being propelled by the motor protein kinesin across the substrate surface. The same instrument was modified to function under total internal reflection scattering (TIRS) microscopy to study metallic anisotropic nanoparticles and their dynamic interactions with synthetic lipid bilayers. Utilizing two illumination lasers with opposite polarization directions at wavelengths corresponding to the short and long axis surface plasmon resonance (SPR) of the nanoparticles, both the in-plane and out-of-plane movements of many particles could be tracked simultaneously. When combined with Gaussian point spread function (PSF) fitting for particle super-localization, the binding status and rotational movement could be resolved without degeneracy. TIRS microscopy was also used to

  5. Low coherence full field interference microscopy or optical coherence tomography: recent advances, limitations and future trends

    NASA Astrophysics Data System (ADS)

    Abdulhalim, I.

    2013-04-01

    Although low coherence microscopy (LCM) has been known for long time in the context of interference microscopy, coherence radar and white light interferometry, the whole subject has attracted a wide interest in the last two decades particularly accelerated by the entrance of OCT, as a noninvasive powerful technique for biomedical imaging. Today LCM can be classified into two types, both acts as three-dimensional imaging tool. The first is low temporal coherence microscopy; also known as optical coherence tomography (OCT), which is being used for medical diagnostics. The second is full field OCT in various modes and applied to various applications. FF-OCT uses low spatial and temporal coherence similar to the well-known coherence probe microscope (CPM) that have been in use for long time in optical metrology. The CPM has many advantages over conventional microscopy in its ability to discriminate between different transparent layers in a scattering medium thus allowing for precise noninvasive optical probing of dense tissue and other turbid media. In this paper the status of this technology in optical metrology applications will be discussed, on which we have been working to improve its performance, as well as its limitations and future prospective.

  6. Axial Plane Optical Microscopy

    PubMed Central

    Li, Tongcang; Ota, Sadao; Kim, Jeongmin; Wong, Zi Jing; Wang, Yuan; Yin, Xiaobo; Zhang, Xiang

    2014-01-01

    We present axial plane optical microscopy (APOM) that can, in contrast to conventional microscopy, directly image a sample's cross-section parallel to the optical axis of an objective lens without scanning. APOM combined with conventional microscopy simultaneously provides two orthogonal images of a 3D sample. More importantly, APOM uses only a single lens near the sample to achieve selective-plane illumination microscopy, as we demonstrated by three-dimensional (3D) imaging of fluorescent pollens and brain slices. This technique allows fast, high-contrast, and convenient 3D imaging of structures that are hundreds of microns beneath the surfaces of large biological tissues. PMID:25434770

  7. Elementary steps at the surface of ice crystals visualized by advanced optical microscopy.

    PubMed

    Sazaki, Gen; Zepeda, Salvador; Nakatsubo, Shunichi; Yokoyama, Etsuro; Furukawa, Yoshinori

    2010-11-16

    Due to the abundance of ice on earth, the phase transition of ice plays crucially important roles in various phenomena in nature. Hence, the molecular-level understanding of ice crystal surfaces holds the key to unlocking the secrets of a number of fields. In this study we demonstrate, by laser confocal microscopy combined with differential interference contrast microscopy, that elementary steps (the growing ends of ubiquitous molecular layers with the minimum height) of ice crystals and their dynamic behavior can be visualized directly at air-ice interfaces. We observed the appearance and lateral growth of two-dimensional islands on ice crystal surfaces. When the steps of neighboring two-dimensional islands coalesced, the contrast of the steps always disappeared completely. We were able to discount the occurrence of steps too small to detect directly because we never observed the associated phenomena that would indicate their presence. In addition, classical two-dimensional nucleation theory does not support the appearance of multilayered two-dimensional islands. Hence, we concluded that two-dimensional islands with elementary height (0.37 and 0.39 nm on basal and prism faces, respectively) were visualized by our optical microscopy. On basal and prism faces, we also observed the spiral growth steps generated by screw dislocations. The distance between adjacent spiral steps on a prism face was about 1/20 of that on a basal face. Hence, the step ledge energy of a prism face was 1/20 of that on a basal face, in accord with the known lower-temperature roughening transition of the prism face.

  8. Optical microscopy aims deep

    NASA Astrophysics Data System (ADS)

    Gigan, Sylvain

    2017-01-01

    A new set of imaging techniques that take advantage of scattered light may soon lead to key advances in biomedical optics, providing access to depths well beyond what is currently possible with ballistic light.

  9. Optical imaging. Expansion microscopy.

    PubMed

    Chen, Fei; Tillberg, Paul W; Boyden, Edward S

    2015-01-30

    In optical microscopy, fine structural details are resolved by using refraction to magnify images of a specimen. We discovered that by synthesizing a swellable polymer network within a specimen, it can be physically expanded, resulting in physical magnification. By covalently anchoring specific labels located within the specimen directly to the polymer network, labels spaced closer than the optical diffraction limit can be isotropically separated and optically resolved, a process we call expansion microscopy (ExM). Thus, this process can be used to perform scalable superresolution microscopy with diffraction-limited microscopes. We demonstrate ExM with apparent ~70-nanometer lateral resolution in both cultured cells and brain tissue, performing three-color superresolution imaging of ~10(7) cubic micrometers of the mouse hippocampus with a conventional confocal microscope.

  10. Advances in combined endoscopic fluorescence confocal microscopy and optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Risi, Matthew D.

    Confocal microendoscopy provides real-time high resolution cellular level images via a minimally invasive procedure. Results from an ongoing clinical study to detect ovarian cancer with a novel confocal fluorescent microendoscope are presented. As an imaging modality, confocal fluorescence microendoscopy typically requires exogenous fluorophores, has a relatively limited penetration depth (100 μm), and often employs specialized aperture configurations to achieve real-time imaging in vivo. Two primary research directions designed to overcome these limitations and improve diagnostic capability are presented. Ideal confocal imaging performance is obtained with a scanning point illumination and confocal aperture, but this approach is often unsuitable for real-time, in vivo biomedical imaging. By scanning a slit aperture in one direction, image acquisition speeds are greatly increased, but at the cost of a reduction in image quality. The design, implementation, and experimental verification of a custom multi-point-scanning modification to a slit-scanning multi-spectral confocal microendoscope is presented. This new design improves the axial resolution while maintaining real-time imaging rates. In addition, the multi-point aperture geometry greatly reduces the effects of tissue scatter on imaging performance. Optical coherence tomography (OCT) has seen wide acceptance and FDA approval as a technique for ophthalmic retinal imaging, and has been adapted for endoscopic use. As a minimally invasive imaging technique, it provides morphological characteristics of tissues at a cellular level without requiring the use of exogenous fluorophores. OCT is capable of imaging deeper into biological tissue (˜1-2 mm) than confocal fluorescence microscopy. A theoretical analysis of the use of a fiber-bundle in spectral-domain OCT systems is presented. The fiber-bundle enables a flexible endoscopic design and provides fast, parallelized acquisition of the optical coherence tomography

  11. Extraterrestrial optical microscopy.

    PubMed

    Soffen, G A

    1969-07-01

    An examination of the literature concerned with the use of microscopy for planetary investigation reveals a serious deficiency of current efforts. Many scientists have recommended the use of a microscope for planetary investigation [Biology and the Exploration of Mars, C. S. Pittendrigh, W. Vishniac, and J. P. T. Pearman, Eds. (National Academy of Science-National Research Council, Washington, D. C., 1966), (a) D. Mazia, p. 31; (b) J. Lederberg, p. 137; (c) S. Fox, pp. 219, 226; (d) D. Glaser, p. 326; (e) D. Glaser, J. McCarthy, and M. Minsky, pp. 333, 341; (f) D. G. Rea, pp. 347-426; (g) P. G. Conger, pp. 409-414; (h) M. H. Fernandez, pp. 414-425; (i) D. Schwartz, pp.425-426 . H. P. Klein, Some Biological Problems in the Search for Extraterrestrial Life (American Astronautical Society, Washington, D. C., 1968).] but few are involved in developing the experiment. Since this is a particularly timely period for the preparation of planetary lander experiments, the reasons for this lack of effort would appear to be limited resources or an unclear course of action, rather than lack of interest. Microscopy used for planetary investigation is chiefly the interest of the biologist and the mineralogist. In both cases the desire to use magnifying optics in order to observe objects of submillimeter size is based upon the rich body of knowledge we have acquired from observing the terrestrial microcosm. In addition to purely imaging, certain special optical techniques, e.g., polarimetry, colorimetry, phase contrast, etc., can be used to enhance the interpretation of microscopic imaging data. This interaction of the optical with the chemical or structural aspects of nature can be used to great advantage in the exploration of extraterrestrial biology and mineralogy.

  12. Advanced electron microscopy for advanced materials.

    PubMed

    Van Tendeloo, Gustaaf; Bals, Sara; Van Aert, Sandra; Verbeeck, Jo; Van Dyck, Dirk

    2012-11-08

    The idea of this Review is to introduce newly developed possibilities of advanced electron microscopy to the materials science community. Over the last decade, electron microscopy has evolved into a full analytical tool, able to provide atomic scale information on the position, nature, and even the valency atoms. This information is classically obtained in two dimensions (2D), but can now also be obtained in 3D. We show examples of applications in the field of nanoparticles and interfaces.

  13. Advances in quantitative Kerr microscopy

    NASA Astrophysics Data System (ADS)

    Soldatov, I. V.; Schäfer, R.

    2017-01-01

    An advanced wide-field Kerr microscopy approach to the vector imaging of magnetic domains is demonstrated. Utilizing the light from eight monochrome light emitting diodes, guided to the microscope by glass fibers, and being properly switched in synchronization with the camera exposure, domain images with orthogonal in-plane sensitivity are obtained simultaneously at real time. After calibrating the Kerr contrast under the same orthogonal sensitivity conditions, the magnetization vector field of complete magnetization cycles along the hysteresis loop can be calculated and plotted as a coded color or vector image. In the pulsed mode also parasitic, magnetic field-dependent Faraday rotations in the microscope optics are eliminated, thus increasing the accuracy of the measured magnetization angles to better than 5∘. The method is applied to the investigation of the magnetization process in a patterned Permalloy film element. Furthermore it is shown that the effective magnetic anisotropy axes in a GaMnAs semiconducting film can be quantitatively measured by vectorial analysis of the domain structure.

  14. Optical scanning holographic microscopy

    NASA Astrophysics Data System (ADS)

    Poon, Ting-Chung; Doh, Kyu B.; Schilling, Bradley W.; Wu, Ming H.; Shinoda, Kazunori K.; Suzuki, Yoshiji

    1995-03-01

    We first review a newly developed 3D imaging technique called optical scanning holography (OSH), and discuss recording and reconstruction of a point object using the principle of OSH. We then derive 3D holographic magnification, using three points configured as a 3D object. Finally, we demonstrated 3D imaging capability of OSH by holographically recording two planar objects at different depths and reconstructing the hologram digitally.

  15. Gabor domain optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Murali, Supraja

    Time domain Optical Coherence Tomography (TD-OCT), first reported in 1991, makes use of the low temporal coherence properties of a NIR broadband laser to create depth sectioning of up to 2mm under the surface using optical interferometry and point to point scanning. Prior and ongoing work in OCT in the research community has concentrated on improving axial resolution through the development of broadband sources and speed of image acquisition through new techniques such as Spectral domain OCT (SD-OCT). In SD-OCT, an entire depth scan is acquired at once with a low numerical aperture (NA) objective lens focused at a fixed point within the sample. In this imaging geometry, a longer depth of focus is achieved at the expense of lateral resolution, which is typically limited to 10 to 20 mum. Optical Coherence Microscopy (OCM), introduced in 1994, combined the advantages of high axial resolution obtained in OCT with high lateral resolution obtained by increasing the NA of the microscope placed in the sample arm. However, OCM presented trade-offs caused by the inverse quadratic relationship between the NA and the DOF of the optics used. For applications requiring high lateral resolution, such as cancer diagnostics, several solutions have been proposed including the periodic manual re-focusing of the objective lens in the time domain as well as the spectral domain C-mode configuration in order to overcome the loss in lateral resolution outside the DOF. In this research, we report for the first time, high speed, sub-cellular imaging (lateral resolution of 2 mum) in OCM using a Gabor domain image processing algorithm with a custom designed and fabricated dynamic focus microscope interfaced to a Ti:Sa femtosecond laser centered at 800 nm within an SD-OCM configuration. It is envisioned that this technology will provide a non-invasive replacement for the current practice of multiple biopsies for skin cancer diagnosis. The research reported here presents three important advances

  16. Advances in Light Microscopy for Neuroscience

    PubMed Central

    Wilt, Brian A.; Burns, Laurie D.; Ho, Eric Tatt Wei; Ghosh, Kunal K.; Mukamel, Eran A.

    2010-01-01

    Since the work of Golgi and Cajal, light microscopy has remained a key tool for neuroscientists to observe cellular properties. Ongoing advances have enabled new experimental capabilities using light to inspect the nervous system across multiple spatial scales, including ultrastructural scales finer than the optical diffraction limit. Other progress permits functional imaging at faster speeds, at greater depths in brain tissue, and over larger tissue volumes than previously possible. Portable, miniaturized fluorescence microscopes now allow brain imaging in freely behaving mice. Complementary progress on animal preparations has enabled imaging in head-restrained behaving animals, as well as time-lapse microscopy studies in the brains of live subjects. Mouse genetic approaches permit mosaic and inducible fluorescence-labeling strategies, whereas intrinsic contrast mechanisms allow in vivo imaging of animals and humans without use of exogenous markers. This review surveys such advances and highlights emerging capabilities of particular interest to neuroscientists. PMID:19555292

  17. Advances in light microscopy for neuroscience.

    PubMed

    Wilt, Brian A; Burns, Laurie D; Wei Ho, Eric Tatt; Ghosh, Kunal K; Mukamel, Eran A; Schnitzer, Mark J

    2009-01-01

    Since the work of Golgi and Cajal, light microscopy has remained a key tool for neuroscientists to observe cellular properties. Ongoing advances have enabled new experimental capabilities using light to inspect the nervous system across multiple spatial scales, including ultrastructural scales finer than the optical diffraction limit. Other progress permits functional imaging at faster speeds, at greater depths in brain tissue, and over larger tissue volumes than previously possible. Portable, miniaturized fluorescence microscopes now allow brain imaging in freely behaving mice. Complementary progress on animal preparations has enabled imaging in head-restrained behaving animals, as well as time-lapse microscopy studies in the brains of live subjects. Mouse genetic approaches permit mosaic and inducible fluorescence-labeling strategies, whereas intrinsic contrast mechanisms allow in vivo imaging of animals and humans without use of exogenous markers. This review surveys such advances and highlights emerging capabilities of particular interest to neuroscientists.

  18. Optical microscopy beyond the diffraction limit

    PubMed Central

    Smolyaninov, Igor I.

    2008-01-01

    Over the past century the resolution of far-field optical microscopes, which rely on propagating optical modes, was widely believed to be limited because of diffraction to a value on the order of a half-wavelength λ∕2 of the light used. Although immersion microscopes had slightly improved resolution on the order of λ∕2n, the increased resolution was limited by the small range of refractive indices, n, of available transparent materials. We are experiencing quick demolition of the diffraction limit in optical microscopy. Over the past few years numerous nonlinear optical microscopy techniques based on photoswitching and saturation of fluorescence demonstrated far-field resolution of 20 to 30 nm. The latest exciting example of these techniques has been demonstrated by Huang et al. [Science 319, 810–813 (2008)]. Moreover, recent progress in metamaterials indicates that artificial optical media can be created, which do not exhibit the diffraction limit. Resolution of linear “immersion” microscopes based on such metamaterials appears limited only by losses, which can be compensated by gain media. Thus, optical microscopy is quickly moving towards the 10 nm resolution scale, which should bring about numerous revolutionary advances in biomedical imaging. PMID:19404465

  19. Conventional and nonlinear optical microscopy of liquid crystal colloids

    NASA Astrophysics Data System (ADS)

    Lee, Taewoo; Smalyukh, Ivan I.

    The fast-growing field of liquid crystal colloids requires increasingly sophisticated optical microscopy tools for experimental studies. Recent technological advances have resulted in a vast body of new imaging modalities, such as nonlinear optical microscopy techniques, that were developed to achieve high resolution while probing director structures and material composition at length scales ranging from hundreds of nanometers to oscopic. These techniques are ideally suited for experimental exploration of liquid crystal colloids. The goal of this chapter is to introduce a variety of optical microscopy techniques available to researchers in the field, starting from basic principles and finishing with a discussion of the most advanced microscopy systems. We describe traditional imaging tools, such as bright field and polarizing optical microscopy, along with state-of-the-art orientationsensitive three-dimensional imaging techniques, such as various nonlinear optical microscopies. Applications of these different imaging approaches are illustrated by providing specific examples of imaging of liquid crystal colloids and other soft matter systems.

  20. Visual-servoing optical microscopy

    DOEpatents

    Callahan, Daniel E.; Parvin, Bahram

    2009-06-09

    The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time: quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

  1. Visual-servoing optical microscopy

    DOEpatents

    Callahan, Daniel E; Parvin, Bahram

    2013-10-01

    The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time; quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

  2. Visual-servoing optical microscopy

    DOEpatents

    Callahan, Daniel E.; Parvin, Bahram

    2011-05-24

    The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time; quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

  3. Advances in fiber lasers for nonlinear microscopy

    NASA Astrophysics Data System (ADS)

    Wise, F. W.; Ouzounov, D.; Kieu, K.; Renninger, W.; Chong, A.; Liu, H.

    2008-02-01

    In the past 30 years major advances in medical imaging have been made in areas such as magnetic resonance imaging, computed tomography, and ultrasound. These techniques have become quite effective for structural imaging at the organ or tissue level, but do not address the clear need for imaging technologies that exploit existing knowledge of the genetic and molecular bases of disease. Techniques that can provide similar information on the cellular and molecular scale would be very powerful, and ultimately the extension of such techniques to in vivo measurements will be desired. The availability of these imaging capabilities would allow monitoring of the early stages of disease or therapy, for example. Optical techniques provide excellent imaging capabilities, with sub-micron spatial resolution, and are noninvasive. An overall goal of biomedical imaging is to obtain diagnostic or functional information about biological structures. The difficulty of acquiring high-resolution images of structures deep in tissue presents a major challenge, however, owing to strong scattering of light. As a consequence, optical imaging has been limited to thin (typically ~0.5 mm) samples or superficial tissue. In contrast, techniques such as ultrasound and magnetic resonance provide images of structures centimeters deep in tissue, with ~100-micron resolution. It is desirable to develop techniques that offer the resolution of optics with the depth-penetration of other techniques. Since 1990, a variety of nonlinear microscopies have been demonstrated. These include 2- and 3-photon fluorescence microscopy, and 2nd- and 3rd-harmonic generation microscopies. These typically employ femtosecond-pulse excitation, for maximum peak power (and thus nonlinear excitation) for a given pulse energy. A relative newcomer to the group is CARS microscopy [1], which exploits resonant vibrational excitation of molecules or bonds. The CARS signal contrast arises from intrinsic elements of cells, and thus

  4. Nonlinear Optical Microscopy of Single Nanostructures

    NASA Astrophysics Data System (ADS)

    Huang, Libai; Cheng, Ji-Xin

    2013-07-01

    We review recent advances in nonlinear optical (NLO) microscopy studies of single nanostructures. NLO signals are intrinsically sensitive to the electronic, vibrational, and structural properties of such nanostructures. Ultrafast excitation allows for mapping of energy relaxation pathways at the single-particle level. The strong nonlinear response of nanostructures makes them highly attractive for applications as novel NLO imaging agents in biological and biomedical research. NLO modalities based on harmonic generation, multiphoton photoluminescence, four-wave mixing, and pump-probe processes are discussed in detail.

  5. Developments in optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Rolland, J. P.; Meemon, P.; Thompson, K. P.; Murali, S.; Lee, K. S.

    2010-11-01

    Optical Coherence Microscopy (OCM) utilizes a high NA microscope objective in the sample arm to achieve an axially and laterally high resolution OCT image. An increase in NA, however, leads to a dramatically decreased depth of focus (DOF), and hence shortens the imaging depth range so that high lateral resolution is maintained only within a small depth region around the focal plane. One solution to increase the depth of imaging while keeping a high lateral resolution is dynamic-focusing. Utilizing the voltage controlled refocus capability of a liquid lens, we have recently presented a solution for invariant high resolution imaging using the liquid lens embedded within a fixed optics hand-held custom microscope designed specifically for optical imaging systems using a broadband light source centered at 800 nm with a 120 nm bandwidth. Subsequently, we have developed a Gabor-Domain Optical Coherence Microscopy (GD-OCM) that utilizes the high speed imaging of spectral domain OCT, the high lateral resolution of OCM, and the ability of real time refocusing of our custom design variable focus objective. Finally, key developments in Phase-Resolved Doppler OCT (PR-DOCT) are key enablers to combine high-resolution structural imaging with functional imaging. In this paper we review achievements in GD-OCM and detail how portions of in-focus cross-sectional images can be extracted and fused to form an invariant lateral resolution image with multiple cross-sectional images acquired corresponding to a discrete refocusing step along depth enabled by the varifocal device. We demonstrate sub-cellular resolution imaging of an African frog tadpole (Xenopus Laevis) taken from a 500 μm × 500 μm cross-section as well as cellular imaging in in vivo skin. Finally, A novel dual-detection full-range Fourier-domain optical coherence tomography system was developed that provides 7 μm axial resolution (in air) at about 90 kHz axial scan rate for mirror-image phase resolved Doppler imaging

  6. Live-cell analysis of plant reproduction: live-cell imaging, optical manipulation, and advanced microscopy technologies.

    PubMed

    Kurihara, Daisuke; Hamamura, Yuki; Higashiyama, Tetsuya

    2013-05-01

    Sexual reproduction ensures propagation of species and enhances genetic diversity within populations. In flowering plants, sexual reproduction requires complicated and multi-step cell-to-cell communications among male and female cells. However, the confined nature of plant reproduction processes, which occur in the female reproductive organs and several cell layers of the pistil, limits our ability to observe these events in vivo. In this review, we discuss recent live-cell imaging in in vitro systems and the optical manipulation techniques that are used to capture the dynamic mechanisms representing molecular and cellular communications in sexual plant reproduction.

  7. Scanning Tunneling Optical Resonance Microscopy

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila; Wilt, Dave; Raffaelle, Ryne; Gennett, Tom; Tin, Padetha; Lau, Janice; Castro, Stephanie; Jenkins, Philip; Scheiman, Dave

    2003-01-01

    Scanning tunneling optical resonance microscopy (STORM) is a method, now undergoing development, for measuring optoelectronic properties of materials and devices on the nanoscale by means of a combination of (1) traditional scanning tunneling microscopy (STM) with (2) tunable laser spectroscopy. In STORM, an STM tip probing a semiconductor is illuminated with modulated light at a wavelength in the visible-to-near-infrared range and the resulting photoenhancement of the tunneling current is measured as a function of the illuminating wavelength. The photoenhancement of tunneling current occurs when the laser photon energy is sufficient to excite charge carriers into the conduction band of the semiconductor. Figure 1 schematically depicts a proposed STORM apparatus. The light for illuminating the semiconductor specimen at the STM would be generated by a ring laser that would be tunable across the wavelength range of interest. The laser beam would be chopped by an achromatic liquid-crystal modulator. A polarization-maintaining optical fiber would couple the light to the tip/sample junction of a commercial STM. An STM can be operated in one of two modes: constant height or constant current. A STORM apparatus would be operated in the constant-current mode, in which the height of the tip relative to the specimen would be varied in order to keep the tunneling current constant. In this mode, a feedback control circuit adjusts the voltage applied to a piezoelectric actuator in the STM that adjusts the height of the STM tip to keep the tunneling current constant. The exponential relationship between the tunneling current and tip-to-sample distance makes it relatively easy to implement this mode of operation. The choice of method by which the photoenhanced portion of the tunneling current would be measured depends on choice of the frequency at which the input illumination would be modulated (chopped). If the frequency of modulation were low enough (typically < 10 Hz) that the

  8. Atomic force microscopy combined with optical microscopy for cells investigation.

    PubMed

    Cascione, Mariafrancesca; de Matteis, Valeria; Rinaldi, Rosaria; Leporatti, Stefano

    2017-01-01

    This review reports on the combined use of the atomic force microscopy (AFM) and several type of optical/fluorescence/laser scanning microscopy for investigating cells. It is shown that the hybrid systems of AFM with optical-derived microscopies enable to study in detail cell surface properties (such as topography), their mechanical properties (e.g., Young's modulus) mechanotransduction phenomena and allow to gain insight into biological-related pathways and mechanisms in the complex nanoworld of cells. Microsc. Res. Tech. 80:109-123, 2017. © 2016 Wiley Periodicals, Inc.

  9. Disposable optics for microscopy diagnostics.

    PubMed

    Vilmi, Pauliina; Varjo, Sami; Sliz, Rafal; Hannuksela, Jari; Fabritius, Tapio

    2015-11-20

    The point-of-care testing (POCT) is having increasing role on modern health care systems due to a possibility to perform tests for patients conveniently and immediately. POCT includes lot of disposable devices because of the environment they are often used. For a disposable system to be reasonably utilized, it needs to be high in quality but low in price. Optics based POCT systems are interesting approach to be developed, and here we describe a low-cost fabrication process for microlens arrays for microscopy. Lens arrays having average lens diameter of 222 μm with 300 μm lens pitch were fabricated. The lenses were characterized to have standard deviation of 0.06 μm in height and 4.61 μm in diameter. The resolution limit of 3.9μm is demonstrated with real images, and the images were compared with ones made with glass and polycarbonate lens arrays. The image quality is at the same level than with the glass lenses and the manufacturing costs are very low, thus making them suitable for POCT applications.

  10. Disposable optics for microscopy diagnostics

    PubMed Central

    Vilmi, Pauliina; Varjo, Sami; Sliz, Rafal; Hannuksela, Jari; Fabritius, Tapio

    2015-01-01

    The point-of-care testing (POCT) is having increasing role on modern health care systems due to a possibility to perform tests for patients conveniently and immediately. POCT includes lot of disposable devices because of the environment they are often used. For a disposable system to be reasonably utilized, it needs to be high in quality but low in price. Optics based POCT systems are interesting approach to be developed, and here we describe a low-cost fabrication process for microlens arrays for microscopy. Lens arrays having average lens diameter of 222 μm with 300 μm lens pitch were fabricated. The lenses were characterized to have standard deviation of 0.06 μm in height and 4.61 μm in diameter. The resolution limit of 3.9μm is demonstrated with real images, and the images were compared with ones made with glass and polycarbonate lens arrays. The image quality is at the same level than with the glass lenses and the manufacturing costs are very low, thus making them suitable for POCT applications. PMID:26586153

  11. Enhancing Quantum Dots for Bioimaging using Advanced Surface Chemistry and Advanced Optical Microscopy: Application to Silicon Quantum Dots (SiQDs).

    PubMed

    Cheng, Xiaoyu; Hinde, Elizabeth; Owen, Dylan M; Lowe, Stuart B; Reece, Peter J; Gaus, Katharina; Gooding, J Justin

    2015-10-28

    Fluorescence lifetime imaging microscopy is successfully demonstrated in both one- and two-photon cases with surface modified, nanocrystalline silicon quantum dots in the context of bioimaging. The technique is further demonstrated in combination with Förster resonance energy transfer studies where the color of the nanoparticles is tuned by using organic dye acceptors directly conjugated onto the nanoparticle surface.

  12. Optical microscopy versus scanning electron microscopy in urolithiasis.

    PubMed

    Marickar, Y M Fazil; Lekshmi, P R; Varma, Luxmi; Koshy, Peter

    2009-10-01

    Stone analysis is incompletely done in many clinical centers. Identification of the stone component is essential for deciding future prophylaxis. X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy (SEM) still remains a distant dream for routine hospital work. It is in this context that optical microscopy is suggested as an alternate procedure. The objective of this article was to assess the utility of an optical microscope which gives magnification of up to 40x and gives clear picture of the surface of the stones. In order to authenticate the morphological analysis of urinary stones, SEM and elemental distribution analysis were performed. A total of 250 urinary stones of different compositions were collected from stone clinic, photographed, observed under an optical microscope, and optical photographs were taken at different angles. Twenty-five representative samples among these were gold sputtered to make them conductive and were fed into the SEM machine. Photographs of the samples were taken at different angles at magnifications up to 4,000. Elemental distribution analysis (EDAX) was done to confirm the composition. The observations of the two studies were compared. The different appearances of the stones under optical illuminated microscopy were mostly standardized appearances, namely bosselations of pure whewellite, spiculations of weddellite, bright yellow colored appearance of uric acid, and dirty white amorphous appearance of phosphates. SEM and EDAX gave clearer pictures and gave added confirmation of the stone composition. From the references thus obtained, it was possible to confirm the composition by studying the optical microscopic pictures. Higher magnification capacity of the SEM and the EDAX patterns are useful to give reference support for performing optical microscopy work. After standardization, routine analysis can be performed with optical microscopy. The advantage of the optical microscope is that, it

  13. Latest advances in commercially available STED microscopy

    NASA Astrophysics Data System (ADS)

    Fouquet, Wernher; Giske, Arnold

    2012-02-01

    STimulated Emission Depletion (STED) microscopy enables imaging of biological samples combining significantly improved optical resolution with all benefits of confocal microscopy. Especially, by combining multi-channel image acquisition with high spatial resolution opens up a new understanding of co-localization experiments on nanoscales. Such a microscope provides new insights in various fields of biology, such as cell and membrane biology, neurobiology and physiology. We present new developments and a variety of biological examples for STED microscopy, showing structural details on scales well below 70nm and give an overview of possible field of applications, mainly focused on live cell imaging.

  14. Advanced optical instruments technology

    NASA Technical Reports Server (NTRS)

    Shao, Mike; Chrisp, Michael; Cheng, Li-Jen; Eng, Sverre; Glavich, Thomas; Goad, Larry; Jones, Bill; Kaarat, Philip; Nein, Max; Robinson, William

    1992-01-01

    The science objectives for proposed NASA missions for the next decades push the state of the art in sensitivity and spatial resolution over a wide range of wavelengths, including the x-ray to the submillimeter. While some of the proposed missions are larger and more sensitive versions of familiar concepts, such as the next generation space telescope, others use concepts, common on the Earth, but new to space, such as optical interferometry, in order to provide spatial resolutions impossible with other concepts. However, despite their architecture, the performance of all of the proposed missions depends critically on the back-end instruments that process the collected energy to produce scientifically interesting outputs. The Advanced Optical Instruments Technology panel was chartered with defining technology development plans that would best improve optical instrument performance for future astrophysics missions. At this workshop the optical instrument was defined as the set of optical components that reimage the light from the telescope onto the detectors to provide information about the spatial, spectral, and polarization properties of the light. This definition was used to distinguish the optical instrument technology issues from those associated with the telescope, which were covered by a separate panel. The panel identified several areas for optical component technology development: diffraction gratings; tunable filters; interferometric beam combiners; optical materials; and fiber optics. The panel also determined that stray light suppression instruments, such as coronagraphs and nulling interferometers, were in need of general development to support future astrophysics needs.

  15. Fibre-optic nonlinear optical microscopy and endoscopy.

    PubMed

    Fu, L; Gu, M

    2007-06-01

    Nonlinear optical microscopy has been an indispensable laboratory tool of high-resolution imaging in thick tissue and live animals. Rapid developments of fibre-optic components in terms of growing functionality and decreasing size provide enormous opportunities for innovations in nonlinear optical microscopy. Fibre-based nonlinear optical endoscopy is the sole instrumentation to permit the cellular imaging within hollow tissue tracts or solid organs that are inaccessible to a conventional optical microscope. This article reviews the current development of fibre-optic nonlinear optical microscopy and endoscopy, which includes crucial technologies for miniaturized nonlinear optical microscopy and their embodiments of endoscopic systems. A particular attention is given to several classes of photonic crystal fibres that have been applied to nonlinear optical microscopy due to their unique properties for ultrashort pulse delivery and signal collection. Furthermore, fibre-optic nonlinear optical imaging systems can be classified into portable microscopes suitable for imaging behaving animals, rigid endoscopes that allow for deep tissue imaging with minimally invasive manners, and flexible endoscopes enabling imaging of internal organs. Fibre-optic nonlinear optical endoscopy is coming of age and a paradigm shift leading to optical microscope tools for early cancer detection and minimally invasive surgery.

  16. Rotary-scanning optical resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Qi, Weizhi; Xi, Lei

    2016-10-01

    Optical resolution photoacoustic microscopy (ORPAM) is currently one of the fastest evolving photoacoustic imaging modalities. It has a comparable spatial resolution to pure optical microscopic techniques such as epifluorescence microscopy, confocal microscopy, and two-photon microscopy, but also owns a deeper penetration depth. In this paper, we report a rotary-scanning (RS)-ORPAM that utilizes a galvanometer scanner integrated with objective to achieve rotary laser scanning. A 15 MHz cylindrically focused ultrasonic transducer is mounted onto a motorized rotation stage to follow optical scanning traces synchronously. To minimize the loss of signal to noise ratio, the acoustic focus is precisely adjusted to reach confocal with optical focus. Black tapes and carbon fibers are firstly imaged to evaluate the performance of the system, and then in vivo imaging of vasculature networks inside the ears and brains of mice is demonstrated using this system.

  17. Characterization of Polymer Blends: Optical Microscopy (*Polarized, Interference and Phase Contrast Microscopy*) and Confocal Microscopy

    SciTech Connect

    Ramanathan, Nathan Muruganathan; Darling, Seth B.

    2015-01-01

    Chapter 15 surveys the characterization of macro, micro and meso morphologies of polymer blends by optical microscopy. Confocal Microscopy offers the ability to view the three dimensional morphology of polymer blends, popular in characterization of biological systems. Confocal microscopy uses point illumination and a spatial pinhole to eliminate out-of focus light in samples that are thicker than the focal plane.

  18. Wavelength Independent Optical Microscopy and Lithography

    DTIC Science & Technology

    1987-10-31

    Leviatan , Y., J. Appl. Phys. 60, 1577 (1986). 7. Harootunian, A., Near-Field Scanning Optical Microscopy and Raman Microscopy, Cornell University Ph.D...although the approach used may not be valid in the Another potential problem concerns the effect of the near field. More recently, Leviatan 21...Massey, "Microscopy and Pattern Generation With Scanned Evanescent Waves," AppL. Opt. 23, 658 (1984). The authors wish to thank Yehuda Leviatan for 21

  19. Optical tweezers for confocal microscopy

    NASA Astrophysics Data System (ADS)

    Hoffmann, A.; Meyer zu Hörste, G.; Pilarczyk, G.; Monajembashi, S.; Uhl, V.; Greulich, K. O.

    2000-11-01

    In confocal laser scanning microscopes (CLSMs), lasers can be used for image formation as well as tools for the manipulation of microscopic objects. In the latter case, in addition to the imaging lasers, the light of an extra laser has to be focused into the object plane of the CLSM, for example as optical tweezers. Imaging as well as trapping by optical tweezers can be done using the same objective lens. In this case, z-sectioning for 3D imaging shifts the optical tweezers with the focal plane of the objective along the optical axis, so that a trapped object remains positioned in the focal plane. Consequently, 3D imaging of trapped objects is impossible without further measures. We present an experimental set-up keeping the axial trapping position of the optical tweezers at its intended position whilst the focal plane can be axially shifted over a distance of about 15 μm. It is based on fast-moving correctional optics synchronized with the objective movement. First examples of application are the 3D imaging of chloroplasts of Elodea densa (Canadian waterweed) in a vigorous cytoplasmic streaming and the displacement of zymogen granules in pancreatic cancer cells (AR42 J).

  20. Advanced Electron Microscopy in Materials Physics

    SciTech Connect

    Zhu, Y.; Jarausch, K.

    2009-06-01

    Aberration correction has opened a new frontier in electron microscopy by overcoming the limitations of conventional round lenses, providing sub-angstrom-sized probes and extending information limits. The imaging and analytical performance of these corrector-equipped microscopes affords an unprecedented opportunity to study structure-property relationships of matter at the atomic scale. This new generation of microscopes is able to retrieve high-quality structural information comparable to neutron and synchrotron x-ray experiments, but with local atomic resolution. These advances in instrumentation are accelerating the research and development of various functional materials ranging from those for energy generation, conversion, transportation and storage to those for catalysis and nano-device applications. The dramatic improvements in electron-beam illumination and detection also present a host of new challenges for the interpretation and optimization of experiments. During 7-9 November 2007, a workshop, entitled 'Aberration Corrected Electron Microscopy in Material Physics', was convened at the Center for Functional Nanomaterials, Brookhaven National Laboratories (BNL) to address these opportunities and challenges. The workshop was co-sponsored by Hitachi High Technologies, a leader in electron microscopy instrumentation, and BNL's Institute of Advanced Electron Microscopy, a leader in materials physics research using electron microscopy. The workshop featured presentations by internationally prominent scientists working at the frontiers of electron microscopy, both on developing instrumentation and applying it in materials physics. The meeting, structured to stimulate scientific exchanges and explore new capabilities, brought together {approx}100 people from over 10 countries. This special issue complies many of the advances in instrument performance and materials physics reported by the invited speakers and attendees at the workshop.

  1. Optical microscopy using a single-molecule light source

    PubMed

    Michaelis; Hettich; Mlynek; Sandoghdar

    2000-05-18

    Rapid progress in science on nanoscopic scales has promoted increasing interest in techniques of ultrahigh-resolution optical microscopy. The diffraction limit can be surpassed by illuminating an object in the near field through a sub-wavelength aperture at the end of a sharp metallic probe. Proposed modifications of this technique involve replacing the physical aperture by a nanoscopic active light source. Advances in the spatial and spectral detection of individual fluorescent molecules, using near-field and far-field methods, suggest the possibility of using a single molecule as the illumination source. Here we present optical images taken with a single molecule as a point-like source of illumination, by combining fluorescence excitation spectroscopy with shear-force microscopy. Our single-molecule probe has potential for achieving molecular resolution in optical microscopy; it should also facilitate controlled studies of nanometre-scale phenomena (such as resonant energy transfer) with improved lateral and axial spatial resolution.

  2. Subwavelength optical microscopy in the far field

    SciTech Connect

    Sun Qingqing; Zubairy, M. Suhail; Al-Amri, M.; Scully, Marlan O.

    2011-06-15

    We present a procedure for subwavelength optical microscopy. The identical atoms are distributed on a plane and shined with a standing wave. We rotate the plane to different angles and record the resonant fluorescence spectra in the far field, from which we can obtain their distance and location information. This procedure also works for atomic separation above one wavelength and therefore provides a seamless microscopy.

  3. Super-resolution optical microscopy: multiple choices.

    PubMed

    Huang, Bo

    2010-02-01

    The recent invention of super-resolution optical microscopy enables the visualization of fine features in biological samples with unprecedented clarity. It creates numerous opportunities in biology because vast amount of previously obscured subcellular processes now can be directly observed. Rapid development in this field in the past two years offers many imaging modalities that address different needs but they also complicates the choice of the 'perfect' method for answering a specific question. Here I will briefly describe the principles of super-resolution optical microscopy techniques and then focus on comparing their characteristics in various aspects of practical applications.

  4. Optical Property Analyses of Plant Cells for Adaptive Optics Microscopy

    NASA Astrophysics Data System (ADS)

    Tamada, Yosuke; Murata, Takashi; Hattori, Masayuki; Oya, Shin; Hayano, Yutaka; Kamei, Yasuhiro; Hasebe, Mitsuyasu

    2014-04-01

    In astronomy, adaptive optics (AO) can be used to cancel aberrations caused by atmospheric turbulence and to perform diffraction-limited observation of astronomical objects from the ground. AO can also be applied to microscopy, to cancel aberrations caused by cellular structures and to perform high-resolution live imaging. As a step toward the application of AO to microscopy, here we analyzed the optical properties of plant cells. We used leaves of the moss Physcomitrella patens, which have a single layer of cells and are thus suitable for optical analysis. Observation of the cells with bright field and phase contrast microscopy, and image degradation analysis using fluorescent beads demonstrated that chloroplasts provide the main source of optical degradations. Unexpectedly, the cell wall, which was thought to be a major obstacle, has only a minor effect. Such information provides the basis for the application of AO to microscopy for the observation of plant cells.

  5. Advanced Optical Fiber Communication Systems

    DTIC Science & Technology

    1992-08-01

    Optical Network with Physical Star Topology," Advanced Fiber Communications Technologies , Leonid G. Kazovsky... advances in the performance and capabilities of optical fiber communication systems. While some of these technologies are interrelated (for example...multi gigabit per second hybrid circuit/packet switched lightwave network ," Proc. SPIE Advanced Fiber Communications Technologies , Boston 󈨟, Sept.

  6. Coherent Nonlinear Optical Imaging: Beyond Fluorescence Microscopy

    PubMed Central

    Min, Wei; Freudiger, Christian W.; Lu, Sijia; Xie, X. Sunney

    2012-01-01

    The quest for ultrahigh detection sensitivity with spectroscopic contrasts other than fluorescence has led to various novel approaches to optical microscopy of biological systems. Coherent nonlinear optical imaging, especially the recently developed nonlinear dissipation microscopy, including stimulated Raman scattering and two photon absorption, and pump-probe microscopy, including stimulated emission, excited state absorption and ground state depletion, provide distinct and powerful image contrasts for non-fluorescent species. Thanks to high-frequency modulation transfer scheme, they exhibit superb detection sensitivity. By directly interrogating vibrational and/or electronic energy levels of molecules, they offer high molecular specificity. Here we review the underlying principles, excitation and detection schemes, as well as exemplary biomedical applications of this emerging class of molecular imaging techniques. PMID:21453061

  7. Coherent nonlinear optical imaging: beyond fluorescence microscopy.

    PubMed

    Min, Wei; Freudiger, Christian W; Lu, Sijia; Xie, X Sunney

    2011-01-01

    The quest for ultrahigh detection sensitivity with spectroscopic contrasts other than fluorescence has led to various novel approaches to optical microscopy of biological systems. Coherent nonlinear optical imaging, especially the recently developed nonlinear dissipation microscopy (including stimulated Raman scattering and two-photon absorption) and pump-probe microscopy (including excited-state absorption, stimulated emission, and ground-state depletion), provides new image contrasts for nonfluorescent species. Thanks to the high-frequency modulation transfer scheme, these imaging techniques exhibit superb detection sensitivity. By directly interrogating vibrational and/or electronic energy levels of molecules, they offer high molecular specificity. Here we review the underlying principles and excitation and detection schemes, as well as exemplary biomedical applications of this emerging class of molecular imaging techniques.

  8. Advanced Adaptive Optics Technology Development

    SciTech Connect

    Olivier, S

    2001-09-18

    The NSF Center for Adaptive Optics (CfAO) is supporting research on advanced adaptive optics technologies. CfAO research activities include development and characterization of micro-electro-mechanical systems (MEMS) deformable mirror (DM) technology, as well as development and characterization of high-resolution adaptive optics systems using liquid crystal (LC) spatial light modulator (SLM) technology. This paper presents an overview of the CfAO advanced adaptive optics technology development activities including current status and future plans.

  9. Virtual k -Space Modulation Optical Microscopy

    NASA Astrophysics Data System (ADS)

    Kuang, Cuifang; Ma, Ye; Zhou, Renjie; Zheng, Guoan; Fang, Yue; Xu, Yingke; Liu, Xu; So, Peter T. C.

    2016-07-01

    We report a novel superresolution microscopy approach for imaging fluorescence samples. The reported approach, termed virtual k -space modulation optical microscopy (VIKMOM), is able to improve the lateral resolution by a factor of 2, reduce the background level, improve the optical sectioning effect and correct for unknown optical aberrations. In the acquisition process of VIKMOM, we used a scanning confocal microscope setup with a 2D detector array to capture sample information at each scanned x -y position. In the recovery process of VIKMOM, we first modulated the captured data by virtual k -space coding and then employed a ptychography-inspired procedure to recover the sample information and correct for unknown optical aberrations. We demonstrated the performance of the reported approach by imaging fluorescent beads, fixed bovine pulmonary artery endothelial (BPAE) cells, and living human astrocytes (HA). As the VIKMOM approach is fully compatible with conventional confocal microscope setups, it may provide a turn-key solution for imaging biological samples with ˜100 nm lateral resolution, in two or three dimensions, with improved optical sectioning capabilities and aberration correcting.

  10. Optical diffraction microscopy in a teaching laboratory

    NASA Astrophysics Data System (ADS)

    Thibault, Pierre; Rankenburg, Ivan C.

    2007-09-01

    We discuss an optics experiment that reproduces all important aspects of diffraction microscopy or coherent diffractive imaging. This technique is used to reconstruct an object's image from its diffraction pattern. The experimental setup is described in detail and only requires material readily available in a well-equipped optics teaching laboratory. The data analysis procedure is explained, in particular the reconstruction part, for which an iterative phase retrieval algorithm is used. The method is illustrated by showing the complex-valued reconstruction of an insect wing from a diffraction pattern measured with this setup.

  11. A near-field optical microscopy nanoarray

    SciTech Connect

    Semin, D.J.; Ambrose, W.P.; Goodwin, P.M.; Kwller, A.; Wendt, J.R.

    1996-12-31

    Multiplexing near-field scanning optical microscopy (NSOM) by the use of a nanoarray with parallel imaging is studied. The fabrication, characterization, and utilization of nanoarrays with {approximately} 100 nm diameter apertures spaced 500 nm center-to- center is presented. Extremely uniform nanoarrays with {approximately} 10{sup 8} apertures were fabricated by electron beam lithography and reactive ion etching. The nanoarrays were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). In this paper we utilize these nanoarrays in a laser-illuminated microscope with parallel detection on a charge- coupled device (CCD). Detection of B-phycoerythrin (B-PE) molecules using near-field illumination is presented. In principle, our system can be used to obtain high lateral resolution NSOM images over a wide-field of view (e.g. 50-100 {mu}m) within seconds.

  12. Optical design of the short pulse x-ray imaging and microscopy time-angle correlated diffraction beamline at the Advanced Photon Source

    NASA Astrophysics Data System (ADS)

    Reininger, R.; Dufresne, E. M.; Borland, M.; Beno, M. A.; Young, L.; Kim, K.-J.; Evans, P. G.

    2013-05-01

    The short pulse x-ray imaging and microscopy beamline is one of the two x-ray beamlines that will take full advantage of the short pulse x-ray source in the Advanced Photon Source (APS) upgrade. A horizontally diffracting double crystal monochromator which includes a sagittally focusing second crystal will collect most of the photons generated when the chirped electron beam traverses the undulator. A Kirkpatrick-Baez mirror system after the monochromator will deliver to the sample a beam which has an approximately linear correlation between time and vertical beam angle. The correlation at the sample position has a slope of 0.052 ps/μrad extending over an angular range of 800 μrad for a cavity deflection voltage of 2 MV. The expected time resolution of the whole system is 2.6 ps. The total flux expected at the sample position at 10 keV with a 0.9 eV energy resolution is 5.7 × 1012 photons/s at a spot having horizontal and vertical full width at half maximum of 33 μm horizontal by 14 μm vertical. This new beamline will enable novel time-dispersed diffraction experiments on small samples using the full repetition rate of the APS.

  13. Advanced electron microscopy characterization of multimetallic nanoparticles

    NASA Astrophysics Data System (ADS)

    Khanal, Subarna Raj

    Research in noble metal nanoparticles has led to exciting progress in a versatile array of applications. For the purpose of better tailoring of nanoparticles activities and understanding the correlation between their structures and properties, control over the composition, shape, size and architecture of bimetallic and multimetallic nanomaterials plays an important role on revealing their new or enhanced functions for potentials application. Advance electron microscopy techniques were used to provide atomic scale insights into the structure-properties of different materials: PtPd, Au-Au3Cu, Cu-Pt, AgPd/Pt and AuCu/Pt nanoparticles. The objective of this work is to understand the physical and chemical properties of nanomaterials and describe synthesis, characterization, surface properties and growth mechanism of various bimetallic and multimetallic nanoparticles. The findings have provided us with novel and significant insights into the physical and chemical properties of noble metal nanoparticles. Different synthesis routes allowed us to synthesize bimetallic: Pt-Pd, Au-Au3Cu, Cu-Pt and trimetallic: AgPd/Pt, AuCu/Pt, core-shell and alloyed nanoparticles with monodispersed sizes, controlled shapes and tunable surface properties. For example, we have synthesized the polyhedral PtPd core-shell nanoparticles with octahedral, decahedral, and triangular plates. Decahedral PtPd core-shell structures are novel morphologies for this system. For the first time we fabricated that the Au core and Au3Cu alloyed shell nanoparticles passivated with CuS2 surface layers and characterized by Cs-corrected scanning transmission electron microscopy. The analysis of the high-resolution micrographs reveals that these nanoparticles have decahedral structure with shell periodicity, and that each of the particles is composed by Au core and Au3Cu ordered superlattice alloyed shell surrounded by CuS 2 surface layer. Additionally, we have described both experimental and theoretical methods of

  14. Single-spin stochastic optical reconstruction microscopy

    PubMed Central

    Pfender, Matthias; Aslam, Nabeel; Waldherr, Gerald; Neumann, Philipp; Wrachtrup, Jörg

    2014-01-01

    We experimentally demonstrate precision addressing of single-quantum emitters by combined optical microscopy and spin resonance techniques. To this end, we use nitrogen vacancy (NV) color centers in diamond confined within a few ten nanometers as individually resolvable quantum systems. By developing a stochastic optical reconstruction microscopy (STORM) technique for NV centers, we are able to simultaneously perform sub–diffraction-limit imaging and optically detected spin resonance (ODMR) measurements on NV spins. This allows the assignment of spin resonance spectra to individual NV center locations with nanometer-scale resolution and thus further improves spatial discrimination. For example, we resolved formerly indistinguishable emitters by their spectra. Furthermore, ODMR spectra contain metrology information allowing for sub–diffraction-limit sensing of, for instance, magnetic or electric fields with inherently parallel data acquisition. As an example, we have detected nuclear spins with nanometer-scale precision. Finally, we give prospects of how this technique can evolve into a fully parallel quantum sensor for nanometer resolution imaging of delocalized quantum correlations. PMID:25267655

  15. Multiparallel Three-Dimensional Optical Microscopy

    NASA Technical Reports Server (NTRS)

    Nguyen, Lam K.; Price, Jeffrey H.; Kellner, Albert L.; Bravo-Zanoquera, Miguel

    2010-01-01

    Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and mirrors that divide the output of the microscope into multiple channels. An imaging array of photodetectors in each channel is located at a different distance along the optical path from the microscope, corresponding to a focal plane at a different depth within the sample. The optical path leading to each photodetector array also includes lenses to compensate for the variation of magnification with distance so that the images ultimately formed on all the photodetector arrays are of the same magnification. The use of optical components common to multiple channels in a simple geometry makes it possible to obtain high light-transmission efficiency with an optically and mechanically simple assembly. In addition, because images can be read out simultaneously from all the photodetector arrays, the apparatus can support three-dimensional imaging at a high scanning rate.

  16. Optical Third-Harmonic Microscopy of Graphene

    NASA Astrophysics Data System (ADS)

    Dadap, Jerry I.; Hong, Sung-Young; Petrone, Nicholas W.; Yeh, Po-Chun; Hone, James C.; Osgood, Richard M., Jr.

    2013-03-01

    We report strong third-harmonic (TH) generation in monolayer graphene mounted on an amorphous silica substrate using a photon energy that is three-photon resonant with the exciton-shifted van Hove singularity at the M-point of graphene. Our polarization-dependent and azimuthal rotation measurements confirm the expected isotropic symmetry properties for the TH nonlinear optical process in graphene. Since this monolayer graphene TH signal exceeds that of bulk glass by more than two orders of magnitude, the signal contrast permits background-free scanning of graphene and provides structural information that is difficult to obtain via linear optical microscopy. We also discuss the dependence of TH signals on the number of graphene layers and compare the graphene signal strength with that from crystalline Au(111) sample. We acknowledge support from AFOSR MURI Program #FA9550-09-1-0705.

  17. Fiber optics for advanced aircraft

    NASA Technical Reports Server (NTRS)

    Baumbick, Robert J.

    1988-01-01

    The increased use of composites makes the digital control more susceptible to electromagnetic effects. In order to provide the protection to the digital control additional shielding will be required as well as protective circuitry for the electronics. This results in increased weight and reduced reliability. The advantages that fiber optic technology provides for advanced aircraft applications is recognized. The use of optical signals to carry information between the aircraft and the control module provides immunity from contamination by electromagnetic sources as well as other important benefits such as reduced weight and volume resulting from the elimination of the shielding and the replacement of metal conductors with low weight glass fibers. In 1975 NASA began work to develop passive optical sensors for use with fiber optics in aircraft control systems. The problem now is to choose the best optical sensor concepts and evaluate them for use. In 1985 NASA and DOD entered into a joint program, Fiber Optic Control System Integration (FOCSI), to look at optical technology specifically for use in advanced aircraft systems. The results of this program are discussed. The conclusion of the study indicated that the use of fiber optic technology in advanced aircraft systems is feasible and desirable. The study pointed to a lack of available sensors from vendors capable of operating in the adverse environments of advanced aircraft.

  18. Fiber optics for advanced aircraft

    NASA Technical Reports Server (NTRS)

    Baumbick, Robert J.

    1989-01-01

    The increased use of composites makes the digital control more susceptible to electromagnetic effects. In order to provide the protection to the digital control additional shielding will be required as well as protective circuitry for the electronics. This results in increased weight and reduced reliability. The advantages that fiber optic technology provides for advanced aircraft applications is recognized. The use of optical signals to carry information between the aircraft and the control module provides immunity from contamination by electromagnetic sources as well as other important benefits such as reduced weight and volume resulting from the elimination of the shielding and the replacement of metal conductors with low weight glass fibers. In 1975 NASA began work to develop passive optical sensors for use with fiber optics in aircraft control systems. The problem now is to choose the best optical sensor concepts and evaluate them for use. In 1985 NASA and DOD entered into a joint program, Fiber Optic Control System Integration (FOCSI), to look at optical technology specifically for use in advanced aircraft systems. The results of this program are discussed. The conclusion of the study indicated that the use of fiber optic technology in advanced aircraft systems is feasible and desirable. The study pointed to a lack of available sensors from vendors capable of operating in the adverse environments of advanced aircraft.

  19. Advanced atomic force microscopy: Development and application

    NASA Astrophysics Data System (ADS)

    Walters, Deron A.

    Over the decade since atomic force microscopy (AFM) was invented, development of new microscopes has been closely intertwined with application of AFM to problems of interest in physics, chemistry, biology, and engineering. New techniques such as tapping mode AFM move quickly in our lab from the designer's bench to the user's table-since this is often the same piece of furniture. In return, designers get ample feedback as to what problems are limiting current instruments, and thus need most urgent attention. Tip sharpness and characterization are such a problem. Chapter 1 describes an AFM designed to operate in a scanning electron microscope, whose electron beam is used to deposit sharp carbonaceous tips. These tips can be tested and used in situ. Another limitation is addressed in Chapter 2: the difficulty of extracting more than just topographic information from a sample. A combined AFM/confocal optical microscope was built to provide simultaneous, independent images of the topography and fluorescence of a sample. In combination with staining or antibody labelling, this could provide submicron information about the composition of a sample. Chapters 3 and 4 discuss two generations of small cantilevers developed for lower-noise, higher-speed AFM of biological samples. In Chapter 4, a 26 mum cantilever is used to image the process of calcite growth from solution at a rate of 1.6 sec/frame. Finally, Chapter 5 explores in detail a biophysics problem that motivates us to develop fast, quiet, and gentle microscopes; namely, the control of crystal growth in seashells by the action of soluble proteins on a growing calcite surface.

  20. Scanning Tunneling Optical Resonance Microscopy Developed

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila G.; Raffaelle, Ryne P.; Lau, Janis E.; Jenkins, Phillip P.; Castro, Stephanie L.; Tin, Padetha; Wilt, David M.; Pal, Anna Maria; Fahey, Stephen D.

    2004-01-01

    The ability to determine the in situ optoelectronic properties of semiconductor materials has become especially important as the size of device architectures has decreased and the development of complex microsystems has increased. Scanning Tunneling Optical Resonance Microscopy, or STORM, can interrogate the optical bandgap as a function of its position within a semiconductor micro-structure. This technique uses a tunable solidstate titanium-sapphire laser whose output is "chopped" using a spatial light modulator and is coupled by a fiber-optic connector to a scanning tunneling microscope in order to illuminate the tip-sample junction. The photoenhanced portion of the tunneling current is spectroscopically measured using a lock-in technique. The capabilities of this technique were verified using semiconductor microstructure calibration standards that were grown by organometallic vapor-phase epitaxy. Bandgaps characterized by STORM measurements were found to be in good agreement with the bulk values determined by transmission spectroscopy and photoluminescence and with the theoretical values that were based on x-ray diffraction results.

  1. Spectral fusing Gabor domain optical coherence microscopy.

    PubMed

    Meemon, Panomsak; Widjaja, Joewono; Rolland, Jannick P

    2016-02-01

    Gabor domain optical coherence microscopy (GD-OCM) is one of many variations of optical coherence tomography (OCT) techniques that aims for invariant high resolution across a 3D field of view by utilizing the ability to dynamically refocus the imaging optics in the sample arm. GD-OCM acquires multiple cross-sectional images at different focus positions of the objective lens, and then fuses them to obtain an invariant high-resolution 3D image of the sample, which comes with the intrinsic drawback of a longer processing time as compared to conventional Fourier domain OCT. Here, we report on an alternative Gabor fusing algorithm, the spectral-fusion technique, which directly processes each acquired spectrum and combines them prior to the Fourier transformation to obtain a depth profile. The implementation of the spectral-fusion algorithm is presented and its performance is compared to that of the prior GD-OCM spatial-fusion approach. The spectral-fusion approach shows twice the speed of the spatial-fusion approach for a spectrum size of less than 2000 point sampling, which is a commonly used spectrum size in OCT imaging, including GD-OCM.

  2. Doppler encoded excitation pattern tomographic optical microscopy.

    PubMed

    Feldkhun, Daniel; Wagner, Kelvin H

    2010-12-01

    Most far-field optical imaging systems rely on lenses and spatially resolved detection to probe distinct locations on the object. We describe and demonstrate a high-speed wide-field approach to imaging that instead measures the complex spatial Fourier transform of the object by detecting its spatially integrated response to dynamic acousto-optically synthesized structured illumination. Tomographic filtered backprojection is applied to reconstruct the object in two or three dimensions. This technique decouples depth of field and working distance from resolution, in contrast to conventional imaging, and can be used to image biological and synthetic structures in fluoresced or scattered light employing coherent or broadband illumination. We discuss the electronically programmable transfer function of the optical system and its implications for imaging dynamic processes. We also explore wide-field fluorescence imaging in scattering media by coherence gating. Finally, we present two-dimensional high-resolution tomographic image reconstructions in both scattered and fluoresced light demonstrating a thousandfold improvement in the depth of field compared to conventional lens-based microscopy.

  3. Multifocal multiphoton microscopy with adaptive optical correction

    NASA Astrophysics Data System (ADS)

    Coelho, Simao; Poland, Simon; Krstajic, Nikola; Li, David; Monypenny, James; Walker, Richard; Tyndall, David; Ng, Tony; Henderson, Robert; Ameer-Beg, Simon

    2013-02-01

    Fluorescence lifetime imaging microscopy (FLIM) is a well established approach for measuring dynamic signalling events inside living cells, including detection of protein-protein interactions. The improvement in optical penetration of infrared light compared with linear excitation due to Rayleigh scattering and low absorption have provided imaging depths of up to 1mm in brain tissue but significant image degradation occurs as samples distort (aberrate) the infrared excitation beam. Multiphoton time-correlated single photon counting (TCSPC) FLIM is a method for obtaining functional, high resolution images of biological structures. In order to achieve good statistical accuracy TCSPC typically requires long acquisition times. We report the development of a multifocal multiphoton microscope (MMM), titled MegaFLI. Beam parallelization performed via a 3D Gerchberg-Saxton (GS) algorithm using a Spatial Light Modulator (SLM), increases TCSPC count rate proportional to the number of beamlets produced. A weighted 3D GS algorithm is employed to improve homogeneity. An added benefit is the implementation of flexible and adaptive optical correction. Adaptive optics performed by means of Zernike polynomials are used to correct for system induced aberrations. Here we present results with significant improvement in throughput obtained using a novel complementary metal-oxide-semiconductor (CMOS) 1024 pixel single-photon avalanche diode (SPAD) array, opening the way to truly high-throughput FLIM.

  4. Advances in renal (patho)physiology using multiphoton microscopy.

    PubMed

    Sipos, A; Toma, I; Kang, J J; Rosivall, L; Peti-Peterdi, J

    2007-11-01

    Multiphoton excitation fluorescence microscopy is a state-of-the-art confocal imaging technique ideal for deep optical sectioning of living tissues. It is capable of performing ultrasensitive, quantitative imaging of organ functions in health and disease with high spatial and temporal resolution which other imaging modalities cannot achieve. For more than a decade, multiphoton microscopy has been successfully used with various in vitro and in vivo experimental approaches to study many functions of different organs, including the kidney. This study focuses on recent advances in our knowledge of renal (patho)physiological processes made possible by the use of this imaging technology. Visualization of cellular variables like cytosolic calcium, pH, cell-to-cell communication and signal propagation, interstitial fluid flow in the juxtaglomerular apparatus (JGA), real-time imaging of tubuloglomerular feedback (TGF), and renin release mechanisms are reviewed. A brief summary is provided of kidney functions that can be measured by in vivo quantitative multiphoton imaging including glomerular filtration and permeability, concentration, dilution, and activity of the intrarenal renin-angiotensin system using this minimally invasive approach. New visual data challenge a number of existing paradigms in renal (patho)physiology. Also, quantitative imaging of kidney function with multiphoton microscopy has tremendous potential to eventually provide novel non-invasive diagnostic and therapeutic tools for future applications in clinical nephrology.

  5. Near Field Scanning Optical Microscopy (NSOM)

    PubMed Central

    Betzig, E.; Lewis, A.; Harootunian, A.; Isaacson, M.; Kratschmer, E.

    1986-01-01

    A new method for high-resolution imaging, near-field scanning optical microscopy (NSOM), has been developed. The concepts governing this method are discussed, and the technical challenges encountered in constructing a working NSOM instrument are described. Two distinct methods are presented for the fabrication of well-characterized, highly reproducible, subwavelength apertures. A sample one-dimensional scan is provided and compared to the scanning electron micrograph of a test pattern. From this comparison, a resolution of > 1,500 Å (i.e., ≃λ/3.6) is determined, which represents a significant step towards our eventual goal of 500 Å resolution. Fluorescence has been observed through apertures smaller than 600 Å and signal-to-noise calculations show that fluorescent imaging should be feasible. The application of such imaging is then discussed in reference to specific biological problems. The NSOM method employs nonionizing visible radiation and can be used in air or aqueous environments for nondestructive visualization of functioning biological systems with a resolution comparable to that of scanning electron microscopy. ImagesFIGURE 4FIGURE 7FIGURE 9FIGURE 10 PMID:19431633

  6. Advanced optical fuzing technology

    NASA Astrophysics Data System (ADS)

    von der Lippe, Christian M.; Liu, J. Jiang

    2005-09-01

    We are developing a robust and compact photonic proximity sensor for munition applications. Successful implementation of this sensor will provide a new capability for direct fire applications. The photonic component development exploits pioneering work and unique expertise at ARDEC, ARL, and Sandia National Laboratories by combining key optoelectronic technologies to design and demonstrate components for this fuzing application. The technologies employed in the optical fuze design are vertical cavity surface-emitting lasers (VCSELs), the p-i-n or metal-semiconductor-metal (MSM) photodetectors, and miniature lenses optics. This work will culminate in a robust, fully integrated, g-hardened component design suitable for proximity fuzing applications. This compact sensor will replace costly assemblies that are based on discrete lasers, photodetectors, and bulk optics. It will be mass manufacturable and impart huge savings for such applications. The specific application under investigation is for gun-fired munitions. Nevertheless, numerous civilian uses exist for this proximity sensor in automotive, robotics and aerospace applications. This technology is also applicable to robotic ladar and short-range 3-D imaging.

  7. Three-dimensional optical-resolution photoacoustic microscopy.

    PubMed

    Hu, Song; Maslov, Konstantin; Wang, Lihong V

    2011-05-03

    Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As the mainstays of in vivo three-dimensional (3-D) optical microscopy, single-/multi-photon fluorescence microscopy and optical coherence tomography (OCT) have demonstrated their extraordinary sensitivities to fluorescence and optical scattering contrasts, respectively. However, the optical absorption contrast of biological tissues, which encodes essential physiological/pathological information, has not yet been assessable. The emergence of biomedical photoacoustics has led to a new branch of optical microscopy optical-resolution photoacoustic microscopy (OR-PAM), where the optical irradiation is focused to the diffraction limit to achieve cellular or even subcellular level lateral resolution. As a valuable complement to existing optical microscopy technologies, OR-PAM brings in at least two novelties. First and most importantly, OR-PAM detects optical absorption contrasts with extraordinary sensitivity (i.e., 100%). Combining OR-PAM with fluorescence microscopy or with optical-scattering-based OCT (or with both) provides comprehensive optical properties of biological tissues. Second, OR-PAM encodes optical absorption into acoustic waves, in contrast to the pure optical processes in fluorescence microscopy and OCT, and provides background-free detection. The acoustic detection in OR-PAM mitigates the impacts of optical scattering on signal degradation and naturally eliminates possible interferences (i.e., crosstalks) between excitation and detection, which is a common problem in fluorescence microscopy due to the overlap between the excitation and fluorescence spectra. Unique for optical absorption imaging, OR-PAM has demonstrated broad biomedical applications since its invention, including, but not limited to, neurology, ophthalmology, vascular biology, and dermatology. In this video, we teach the system

  8. Microscopy imaging device with advanced imaging properties

    DOEpatents

    Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

    2016-10-25

    Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

  9. Microscopy imaging device with advanced imaging properties

    DOEpatents

    Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

    2016-11-22

    Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

  10. Microscopy imaging device with advanced imaging properties

    DOEpatents

    Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

    2015-11-24

    Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

  11. Application of scanning acoustic microscopy to advanced structural ceramics

    NASA Technical Reports Server (NTRS)

    Vary, Alex; Klima, Stanley J.

    1987-01-01

    A review is presentod of research investigations of several acoustic microscopy techniques for application to structural ceramics for advanced heat engines. Results obtained with scanning acoustic microscopy (SAM), scanning laser acoustic microscopy (SLAM), scanning electron acoustic microscopy (SEAM), and photoacoustic microscopy (PAM) are compared. The techniques were evaluated on research samples of green and sintered monolithic silicon nitrides and silicon carbides in the form of modulus-of-rupture bars containing deliberately introduced flaws. Strengths and limitations of the techniques are described with emphasis on statistics of detectability of flaws that constitute potential fracture origins.

  12. In situ observation of biotite (001) surface dissolution at pH 1 and 9.5 by advanced optical microscopy

    PubMed Central

    Lamarca-Irisarri, Daniel; Camas, Jordi; Huertas, F Javier

    2015-01-01

    Summary Laser confocal differential interference contrast microscopy (LCM-DIM) allows for the study of the reactivity of surface minerals with slow dissolution rates (e.g., phyllosilicates). With this technique, it is possible to carry out in situ inspection of the reacting surface in a broad range of pH, ionic strength and temperature providing useful information to help unravel the dissolution mechanisms of phyllosilicates. In this work, LCM-DIM was used to study the mechanisms controlling the biotite (001) surface dissolution at pH 1 (11 and 25 °C) and pH 9.5 (50 °C). Step edges are the preferential sites of dissolution and lead to step retreat, regardless of the solution pH. At pH 1, layer swelling and peeling takes place, whereas at pH 9.5 fibrous structures (streaks) form at the step edges. Confocal Raman spectroscopy characterization of the reacted surface could not confirm if the formation of a secondary phase was responsible for the presence of these structures. PMID:25821706

  13. Advanced optical condition monitoring. [of rocket engines

    NASA Technical Reports Server (NTRS)

    Cross, G.; Barkhoudarian, S.

    1991-01-01

    The application of Advanced Optical Condition Monitoring to optical leak detection and plume spectrometry is discussed. The development of these selected sensors for propulsion system monitoring is addressed.

  14. Stitching Techniques Advance Optics Manufacturing

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Because NASA depends on the fabrication and testing of large, high-quality aspheric (nonspherical) optics for applications like the James Webb Space Telescope, it sought an improved method for measuring large aspheres. Through Small Business Innovation Research (SBIR) awards from Goddard Space Flight Center, QED Technologies, of Rochester, New York, upgraded and enhanced its stitching technology for aspheres. QED developed the SSI-A, which earned the company an R&D 100 award, and also developed a breakthrough machine tool called the aspheric stitching interferometer. The equipment is applied to advanced optics in telescopes, microscopes, cameras, medical scopes, binoculars, and photolithography."

  15. Advanced optical manufacturing digital integrated system

    NASA Astrophysics Data System (ADS)

    Tao, Yizheng; Li, Xinglan; Li, Wei; Tang, Dingyong

    2012-10-01

    It is necessarily to adapt development of advanced optical manufacturing technology with modern science technology development. To solved these problems which low of ration, ratio of finished product, repetition, consistent in big size and high precision in advanced optical component manufacturing. Applied business driven and method of Rational Unified Process, this paper has researched advanced optical manufacturing process flow, requirement of Advanced Optical Manufacturing integrated System, and put forward architecture and key technology of it. Designed Optical component core and Manufacturing process driven of Advanced Optical Manufacturing Digital Integrated System. the result displayed effective well, realized dynamic planning Manufacturing process, information integration improved ratio of production manufactory.

  16. Brillouin Optical Microscopy for Corneal Biomechanics

    PubMed Central

    Scarcelli, Giuliano; Pineda, Roberto

    2012-01-01

    Purpose. The mechanical properties of corneal tissue are linked to prevalent ocular diseases and therapeutic procedures. Brillouin microscopy is a novel optical technology that enables three-dimensional mechanical imaging. In this study, the feasibility of this noncontact technique was tested for in situ quantitative assessment of the biomechanical properties of the cornea. Methods. Brillouin light-scattering involves a spectral shift proportional to the longitudinal modulus of elasticity of the tissue. A 532-nm single-frequency laser and a custom-developed ultrahigh-resolution spectrometer were used to measure the Brillouin frequency. Confocal scanning was used to perform Brillouin elasticity imaging of the corneas of whole bovine eyes. The longitudinal modulus of the bovine corneas was compared before and after riboflavin corneal collagen photo-cross-linking. The Brillouin measurements were then compared with conventional stress–strain mechanical test results. Results. High-resolution Brillouin images of the cornea were obtained, revealing a striking depth-dependent variation of the elastic modulus across the cornea. Along the central axis, the Brillouin frequency shift varied gradually from 8.2 GHz in the epithelium to 7.5 GHz near the endothelium. The coefficients of the down slope were measured to be approximately 1.09, 0.32, and 2.94 GHz/mm in the anterior, posterior, and innermost stroma, respectively. On riboflavin collagen cross-linking, marked changes in the axial Brillouin profiles (P < 0.001) were noted before and after cross-linking. Conclusions. Brillouin imaging can assess the biomechanical properties of cornea in situ with high spatial resolution. This novel technique has the potential for use in clinical diagnostics and treatment monitoring. PMID:22159012

  17. Review on advances in nanoscale microscopy in cement research.

    PubMed

    Sharif, Ahmed

    2016-01-01

    With the rapid advancement of nanotechnology, manipulation and characterization of materials in nano scale have become an obvious part of construction related technology. This review will focus on some of the nanoscopy techniques that are most frequently used in current research of cement based nanostructured materials. In particular scanning electron microscopy, transmission electron microscopy, atomic force microscopy, scanning tunneling microscopy, tomography, scanning transmission X-ray microscopy and laser scanning confocal microscopy are addressed. A number of case studies related to microscopic characterization of nano materials utilizing the aforementioned techniques from the published literature are discussed. While these approaches are beginning to yield promising insight, continued progress will definitely provide a potential sustainable solution for the design, development and promotion towards nanoscale engineering of cementitious materials.

  18. Optical super-resolution microscopy in neurobiology.

    PubMed

    Sigrist, Stephan J; Sabatini, Bernardo L

    2012-02-01

    Understanding the highly plastic nature of neurons requires the dynamic visualization of their molecular and cellular organization in a native context. However, due to the limited resolution of standard light microscopy, many of the structural specializations of neurons cannot be resolved. A recent revolution in light microscopy has given rise to several super-resolution light microscopy methods yielding 2-10-fold higher resolution than conventional microscopy. We here describe the principles behind these techniques as well as their application to the analysis of the molecular architecture of the synapse. Furthermore, we discuss the potential for continued development of super-resolution microscopy as necessary for live imaging of neuronal structure and function in the brain.

  19. Confocal and Two-Photon Microscopy: Foundations, Applications and Advances

    NASA Astrophysics Data System (ADS)

    Diaspro, Alberto

    2001-11-01

    Confocal and Two-Photon Microscopy Foundations, Applications, and Advances Edited by Alberto Diaspro Confocal and two-photon fluorescence microscopy has provided researchers with unique possibilities of three-dimensional imaging of biological cells and tissues and of other structures such as semiconductor integrated circuits. Confocal and Two-Photon Microscopy: Foundations, Applications, and Advances provides clear, comprehensive coverage of basic foundations, modern applications, and groundbreaking new research developments made in this important area of microscopy. Opening with a foreword by G. J. Brakenhoff, this reference gathers the work of an international group of renowned experts in chapters that are logically divided into balanced sections covering theory, techniques, applications, and advances, featuring: In-depth discussion of applications for biology, medicine, physics, engineering, and chemistry, including industrial applications Guidance on new and emerging imaging technology, developmental trends, and fluorescent molecules Uniform organization and review-style presentation of chapters, with an introduction, historical overview, methodology, practical tips, applications, future directions, chapter summary, and bibliographical references Companion FTP site with full-color photographs The significant experience of pioneers, leaders, and emerging scientists in the field of confocal and two-photon excitation microscopy Confocal and Two-Photon Microscopy: Foundations, Applications, and Advances is invaluable to researchers in the biological sciences, tissue and cellular engineering, biophysics, bioengineering, physics of matter, and medicine, who use these techniques or are involved in developing new commercial instruments.

  20. The advanced LIGO input optics

    NASA Astrophysics Data System (ADS)

    Mueller, Chris L.; Arain, Muzammil A.; Ciani, Giacomo; DeRosa, Ryan. T.; Effler, Anamaria; Feldbaum, David; Frolov, Valery V.; Fulda, Paul; Gleason, Joseph; Heintze, Matthew; Kawabe, Keita; King, Eleanor J.; Kokeyama, Keiko; Korth, William Z.; Martin, Rodica M.; Mullavey, Adam; Peold, Jan; Quetschke, Volker; Reitze, David H.; Tanner, David B.; Vorvick, Cheryl; Williams, Luke F.; Mueller, Guido

    2016-01-01

    The advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented sensitivity to the strains caused by passing gravitational waves. The input optics play a significant part in allowing these devices to reach such sensitivities. Residing between the pre-stabilized laser and the main interferometer, the input optics subsystem is tasked with preparing the laser beam for interferometry at the sub-attometer level while operating at continuous wave input power levels ranging from 100 mW to 150 W. These extreme operating conditions required every major component to be custom designed. These designs draw heavily on the experience and understanding gained during the operation of Initial LIGO and Enhanced LIGO. In this article, we report on how the components of the input optics were designed to meet their stringent requirements and present measurements showing how well they have lived up to their design.

  1. The advanced LIGO input optics

    SciTech Connect

    Mueller, Chris L. Arain, Muzammil A.; Ciani, Giacomo; Feldbaum, David; Fulda, Paul; Gleason, Joseph; Heintze, Matthew; Martin, Rodica M.; Reitze, David H.; Tanner, David B.; Williams, Luke F.; Mueller, Guido; DeRosa, Ryan T.; Effler, Anamaria; Kokeyama, Keiko; Frolov, Valery V.; Mullavey, Adam; Kawabe, Keita; Vorvick, Cheryl; King, Eleanor J.; and others

    2016-01-15

    The advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented sensitivity to the strains caused by passing gravitational waves. The input optics play a significant part in allowing these devices to reach such sensitivities. Residing between the pre-stabilized laser and the main interferometer, the input optics subsystem is tasked with preparing the laser beam for interferometry at the sub-attometer level while operating at continuous wave input power levels ranging from 100 mW to 150 W. These extreme operating conditions required every major component to be custom designed. These designs draw heavily on the experience and understanding gained during the operation of Initial LIGO and Enhanced LIGO. In this article, we report on how the components of the input optics were designed to meet their stringent requirements and present measurements showing how well they have lived up to their design.

  2. Exploring lipids with nonlinear optical microscopy in multiple biological systems

    NASA Astrophysics Data System (ADS)

    Alfonso-Garcia, Alba

    spontaneous Raman spectroscopy. We used synthesized highly-deuterated cholesterol to track its compartmentalization in adrenal cells, revealing heterogeneous lipid droplet content. These examples illustrate the potential of label-free nonlinear optical microscopy for unveiling complex physiological processes by direct visualization of lipids. Detailed image analysis and combined microscopy modalities will continue to reveal and quantify fundamental biology that will support the advance of biomedicine.

  3. Studies in Confocal Scanning Optical Microscopy

    NASA Astrophysics Data System (ADS)

    Corle, Timothy Richard

    Optical microscopes have been used as measurement tools in many areas of science of the past 300 years. Despite their maturity, there is still active research in the field. In particular the development of confocal scanning optical microscopes (CSOMs) in the 1970's has extended the usefulness of optical microscopes by giving them depth imaging capabilities. In a CSOM a defocused image disappears rather than blurring as it does with a standard microscope. The shallow depth of focus allows structures with a height difference smaller than one wavelength to be imaged independently, and thus quantitative measurements of height can be made. The design and construction of two CSOMs is discussed. The first is a mechanically scanned single pinhole microscope. This instrument was developed as a test bed on which to try out ideas relating to phase contrast imaging. The second is a Nipkow disk based real-time confocal scanning optical microscope (RSOM). These two microscopes were used to investigate the transverse and depth resolution of CSOMs. It is demonstrated that although they do not intrinsically have any better transverse resolution than a standard optical microscope, CSOMs produce a visually sharper image with increased contrast. The depth response of the CSOM is also investigated. A vector theory for the depth response is derived and compared with experimental results. It is shown that previously unexplained asymmetries in the sidelobe structure of this response can be accounted for by aberrations in the microscope objective. Phase contrast images can be generated by periodically defocusing the microscope, either mechanically or electro -optically and detecting a signal at the modulation frequency. A new electro-optic phase contrast microscope is described. The microscope is used to quantitatively measure both the height and width of thin film gratings. The depth response and point spread function of this microscope are also derived. It is shown that the sidelobe

  4. Confocal microscopy of skin cancers: Translational advances toward clinical utility

    PubMed Central

    Rajadhyaksha, Milind

    2014-01-01

    Recent advances in translational research in and technology for confocal microscopy of skin cancers, toward clinical applications, are described. Advances in translational research are in diagnosis of melanoma in vivo, pre-operative mapping of lentigo maligna melanoma margins to guide surgery and intra-operative imaging of residual basal cell carcinomas to guide shave-biopsy. Advances in technology include mosaicing microscopy for detection of basal cell carcinomas in large areas of excised tissue, toward rapid pathology-at-the-bedside, and development of small, simple and low-cost line-scanning confocal microscopes for worldwide use in diverse primary healthcare settings. Current limitations and future opportunities and challenges for both clinicians and technologists are discussed. PMID:19964286

  5. Session: CSP Advanced Systems: Optical Materials (Presentation)

    SciTech Connect

    Kennedy, C.

    2008-04-01

    The Optical Materials project description is to characterize advanced reflector, perform accelerated and outdoor testing of commercial and experimental reflector materials, and provide industry support.

  6. Simultaneous differential spinning disk fluorescence optical sectioning microscopy and nanomechanical mapping atomic force microscopy

    SciTech Connect

    Miranda, Adelaide; De Beule, Pieter A. A.

    2015-09-15

    Combined microscopy techniques offer the life science research community a powerful tool to investigate complex biological systems and their interactions. Here, we present a new combined microscopy platform based on fluorescence optical sectioning microscopy through aperture correlation microscopy with a Differential Spinning Disk (DSD) and nanomechanical mapping with an Atomic Force Microscope (AFM). The illumination scheme of the DSD microscope unit, contrary to standard single or multi-point confocal microscopes, provides a time-independent illumination of the AFM cantilever. This enables a distortion-free simultaneous operation of fluorescence optical sectioning microscopy and atomic force microscopy with standard probes. In this context, we discuss sample heating due to AFM cantilever illumination with fluorescence excitation light. Integration of a DSD fluorescence optical sectioning unit with an AFM platform requires mitigation of mechanical noise transfer of the spinning disk. We identify and present two solutions to almost annul this noise in the AFM measurement process. The new combined microscopy platform is applied to the characterization of a DOPC/DOPS (4:1) lipid structures labelled with a lipophilic cationic indocarbocyanine dye deposited on a mica substrate.

  7. Adaptive optics in digital micromirror based confocal microscopy

    NASA Astrophysics Data System (ADS)

    Pozzi, P.; Wilding, D.; Soloviev, O.; Vdovin, G.; Verhaegen, M.

    2016-03-01

    This proceeding reports early results in the development of a new technique for adaptive optics in confocal microscopy. The term adaptive optics refers to the branch of optics in which an active element in the optical system is used to correct inhomogeneities in the media through which light propagates. In its most classical form, mostly used in astronomical imaging, adaptive optics is achieved through a closed loop in which the actuators of a deformable mirror are driven by a wavefront sensor. This approach is severely limited in fluorescence microscopy, as the use of a wavefront sensor requires the presence of a bright, point like source in the field of view, a condition rarely satisfied in microscopy samples. Previously reported approaches to adaptive optics in fluorescence microscopy are therefore limited to the inclusion of fluorescent microspheres in the sample, to use as bright stars for wavefront sensors, or time consuming sensorless optimization procedures, requiring several seconds of optimization before the acquisition of a single image. We propose an alternative approach to the problem, implementing sensorless adaptive optics in a Programmable array microscope. A programmable array microscope is a microscope based on a digital micromirror device, in which the single elements of the micromirror act both as point sources and pinholes.

  8. 3D high resolution pure optical photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Xie, Zhixing; Chen, Sung-Liang; Ling, Tao; Guo, L. Jay; Carson, Paul L.; Wang, Xueding

    2012-02-01

    The concept of pure optical photoacoustic microscopy(POPAM) was proposed based on optical rastering of a focused excitation beam and optically sensing the photoacoustic signal using a microring resonator fabricated by a nanoimprinting technique. After some refinedment of in the resonator structure and mold fabrication, an ultrahigh Q factor of 3.0×105 was achieved which provided high sensitivity with a noise equivalent detectable pressure(NEDP) value of 29Pa. This NEDP is much lower than the hundreds of Pascals achieved with existing optical resonant structures such as etalons, fiber gratings and dielectric multilayer interference filters available for acoustic measurement. The featured high sensitivity allowed the microring resonator to detect the weak photoacoustic signals from micro- or submicroscale objects. The inherent superbroad bandwidth of the optical microring resonator combined with an optically focused scanning beam provided POPAM of high resolution in the axial as well as both lateral directions while the axial resolution of conventional photoacoustic microscopy (PAM) suffers from the limited bandwidth of PZT detectors. Furthermore, the broadband microring resonator showed similar sensitivity to that of our most sensitive PZT detector. The current POPAM system provides a lateral resolution of 5μm and an axial resolution of 8μm, comparable to that achieved by optical microscopy while presenting the unique contrast of optical absorption and functional information complementing other optical modalities. The 3D structure of microvasculature, including capillary networks, and even individual red blood cells have been discerned successfully in the proof-of-concept experiments on mouse bladders ex vivo and mouse ears in vivo. The potential of approximately GHz bandwidth of the microring resonator also might allow much higher resolution than shown here in microscopy of optical absorption and acoustic propagation properties at depths in unfrozen tissue

  9. Reconstruction in interferometric synthetic aperture microscopy: comparison with optical coherence tomography and digital holographic microscopy.

    PubMed

    Sheppard, Colin J R; Kou, Shan Shan; Depeursinge, Christian

    2012-03-01

    It is shown that the spatial frequencies recorded in interferometric synthetic aperture microscopy do not correspond to exact backscattering [as they do in unistatic synthetic aperture radar (SAR)] and that the reconstruction process based on SAR is therefore based on an approximation. The spatial frequency response is developed based on the three-dimensional coherent transfer function approach and compared with that in optical coherence tomography and digital holographic microscopy.

  10. Aberrations and adaptive optics in super-resolution microscopy.

    PubMed

    Booth, Martin; Andrade, Débora; Burke, Daniel; Patton, Brian; Zurauskas, Mantas

    2015-08-01

    As one of the most powerful tools in the biological investigation of cellular structures and dynamic processes, fluorescence microscopy has undergone extraordinary developments in the past decades. The advent of super-resolution techniques has enabled fluorescence microscopy - or rather nanoscopy - to achieve nanoscale resolution in living specimens and unravelled the interior of cells with unprecedented detail. The methods employed in this expanding field of microscopy, however, are especially prone to the detrimental effects of optical aberrations. In this review, we discuss how super-resolution microscopy techniques based upon single-molecule switching, stimulated emission depletion and structured illumination each suffer from aberrations in different ways that are dependent upon intrinsic technical aspects. We discuss the use of adaptive optics as an effective means to overcome this problem.

  11. Study of nanoscale structural biology using advanced particle beam microscopy

    NASA Astrophysics Data System (ADS)

    Boseman, Adam J.

    This work investigates developmental and structural biology at the nanoscale using current advancements in particle beam microscopy. Typically the examination of micro- and nanoscale features is performed using scanning electron microscopy (SEM), but in order to decrease surface charging, and increase resolution, an obscuring conductive layer is applied to the sample surface. As magnification increases, this layer begins to limit the ability to identify nanoscale surface structures. A new technology, Helium Ion Microscopy (HIM), is used to examine uncoated surface structures on the cuticle of wild type and mutant fruit flies. Corneal nanostructures observed with HIM are further investigated by FIB/SEM to provide detailed three dimensional information about internal events occurring during early structural development. These techniques are also used to reconstruct a mosquito germarium in order to characterize unknown events in early oogenesis. Findings from these studies, and many more like them, will soon unravel many of the mysteries surrounding the world of developmental biology.

  12. Force feedback microscopy based on an optical beam deflection scheme

    SciTech Connect

    Vitorino, Miguel V.; Rodrigues, Mario S.; Carpentier, Simon; Costa, Luca

    2014-07-07

    Force feedback microscopy circumvents the jump to contact in atomic force microscopy when using soft cantilevers and quantitatively measures the interaction properties at the nanoscale by simultaneously providing force, force gradient, and dissipation. The force feedback microscope developed so far used an optical cavity to measure the tip displacement. In this Letter, we show that the more conventional optical beam deflection scheme can be used to the same purpose. With this instrument, we have followed the evolution of the Brownian motion of the tip under the influence of a water bridge.

  13. Probing graphene defects and estimating graphene quality with optical microscopy

    SciTech Connect

    Lai, Shen; Kyu Jang, Sung; Jae Song, Young; Lee, Sungjoo

    2014-01-27

    We report a simple and accurate method for detecting graphene defects that utilizes the mild, dry annealing of graphene/Cu films in air. In contrast to previously reported techniques, our simple approach with optical microscopy can determine the density and degree of dislocation of defects in a graphene film without inducing water-related damage or functionalization. Scanning electron microscopy, confocal Raman and atomic force microscopy, and X-ray photoelectron spectroscopy analysis were performed to demonstrate that our nondestructive approach to characterizing graphene defects with optimized thermal annealing provides rapid and comprehensive determinations of graphene quality.

  14. Where Do We Stand with Super-Resolution Optical Microscopy?

    PubMed

    Nienhaus, Karin; Nienhaus, G Ulrich

    2016-01-29

    Super-resolution fluorescence microscopy has become an invaluable, powerful approach to study biomolecular dynamics and interactions via selective labeling and observation of specific molecules in living cells, tissues and even entire organisms. In this perspective, we present a brief overview of the main techniques and their application to cellular biophysics. We place special emphasis on super-resolution imaging via single-molecule localization microscopy and stimulated emission depletion/reversible saturable optical fluorescence transitions microscopy, and we also briefly address fluorescence fluctuation approaches, notably raster image correlation spectroscopy, as tools to record fast diffusion and transport.

  15. Optical characters of prostate using nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Wu, Shulian; Li, Hui; Zhang, Xiaoman; Wang, Yunxia; Peng, Dongqing

    2012-12-01

    The incidence rate of the prostatic hyperplasia is increasing in near decade, early detection is important for preventing the prostatic cancer (PCa). In this study, the images of prostate and cavernous nerves were carried out using intrinsic fluorescence and scattering properties of the tissues without any exogenous dye or contrast agent based on nonlinear optical microscope. The texture feature and optical property of the interfibrillar substance in prostate tissue were extracted and analyzed for charactering the prostate structure. It will be the feature parameter to differentiate the normal, the inflammation or cancer of prostate tissue in clinical with the application of miniature endoscope nonlinear optical microscope in vivo.

  16. Advanced electron microscopy characterization of nanomaterials for catalysis

    DOE PAGES

    Su, Dong

    2017-02-11

    Transmission electron microscopy (TEM) has become one of the most powerful techniques in the fields of material science, inorganic chemistry and nanotechnology. In terms of resolutions, advanced TEM may reach a high spatial resolution of 0.05 nm, a high energy-resolution of 7 meV. In addition, in situ TEM can help researcher to image the process happened within 1 ms. This paper reviews the recent technical approaches of applying advanced TEM characterization on nanomaterials for catalysis. The text is organized according to the demanded information of nanocrystals from the perspective of application: for example, size, composition, phase, strain, and morphology. Themore » electron beam induced effect and in situ TEM are also introduced. As a result, I hope this review can help the scientists in related fields to take advantage of advanced TEM to their own researches.« less

  17. Incorporating Basic Optical Microscopy in the Instrumental Analysis Laboratory

    ERIC Educational Resources Information Center

    Flowers, Paul A.

    2011-01-01

    A simple and versatile approach to incorporating basic optical microscopy in the undergraduate instrumental analysis laboratory is described. Attaching a miniature CCD spectrometer to the video port of a standard compound microscope yields a visible microspectrophotometer suitable for student investigations of fundamental spectrometry concepts,…

  18. Versatile optical microscopy using a reconfigurable hemispherical digital condenser

    PubMed Central

    Sen, Sanchari; Molina, Luis; Cao, Dongyu; Desai, Darshan B.; Bernussi, Ayrton A.; Grave de Peralta, Luis

    2015-01-01

    We present a computer-controlled hemispherical digital condenser and demonstrate that a single device can be used to implement a variety of both well established and novel optical microscopy techniques. We verified the condenser capabilities by imaging fabricated periodic patterned structures and biological samples. PMID:25798294

  19. Quantitative Topographical Characterization of Thermally Sprayed Coatings by Optical Microscopy

    NASA Astrophysics Data System (ADS)

    Schwaller, P.; Züst, R.; Michler, J.

    2009-03-01

    Topography measurements and roughness calculations for different rough surfaces (Rugotest surface comparator and thermally sprayed coatings) are presented. The surfaces are measured with a novel quantitative topography measurement technique based on optical stereomicroscopy and a comparison is made with established scanning stylus and optical profilometers. The results show that for most cases the different methods yield similar results. Stereomicroscopy is therefore a valuable method for topographical investigations in both quality control and research. On the other hand, the method based on optical microscopy demands a careful optimization of the experimental settings like the magnification and the illumination to achieve satisfactory results.

  20. Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications.

    PubMed

    Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W; Dokmeci, Mehmet Remzi; Boyden, Edward S; Khademhosseini, Ali

    2016-03-15

    To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such "hybrid microscopy" methods--combining physical and optical magnifications--can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes ("mini-microscopes"), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics--a process we refer to as Expansion Mini-Microscopy (ExMM)--is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places.

  1. Advanced Adaptive Optics Control Techniques

    DTIC Science & Technology

    1979-01-01

    Optimal estimation and control methods for high energy laser adaptive optics systems are described. Three system types are examined: Active...the adaptive optics approaches and potential system implementations are recommended.

  2. Gabor-based fusion technique for Optical Coherence Microscopy.

    PubMed

    Rolland, Jannick P; Meemon, Panomsak; Murali, Supraja; Thompson, Kevin P; Lee, Kye-sung

    2010-02-15

    We recently reported on an Optical Coherence Microscopy technique, whose innovation intrinsically builds on a recently reported - 2 microm invariant lateral resolution by design throughout a 2 mm cubic full-field of view - liquid-lens-based dynamic focusing optical probe [Murali et al., Optics Letters 34, 145-147, 2009]. We shall report in this paper on the image acquisition enabled by this optical probe when combined with an automatic data fusion method developed and described here to produce an in-focus high resolution image throughout the imaging depth of the sample. An African frog tadpole (Xenopus laevis) was imaged with the novel probe and the Gabor-based fusion technique, demonstrating subcellular resolution in a 0.5 mm (lateral) x 0.5 mm (axial) without the need, for the first time, for x-y translation stages, depth scanning, high-cost adaptive optics, or manual intervention. In vivo images of human skin are also presented.

  3. Mueller matrix signature in advanced fluorescence microscopy imaging

    NASA Astrophysics Data System (ADS)

    Mazumder, Nirmal; Qiu, Jianjun; Kao, Fu-Jen; Diaspro, Alberto

    2017-02-01

    We have demonstrated the measurement and characterization of the polarization properties of a fluorescence signal using four-channel photon counting based Stokes-Mueller polarization microscopy. Thus, Lu-Chipman decomposition was applied to extract the critical polarization properties such as depolarization, linear retardance and the optical rotation of collagen type I fiber. We observed the spatial distribution of anisotropic and helical molecules of collagen from the reconstructed 2D Mueller images based on the fluorescence signal in a pixel-by-pixel manner.

  4. A Correlative Optical Microscopy and Scanning Electron Microscopy Approach to Locating Nanoparticles in Brain Tumors

    PubMed Central

    Kempen, Paul J.; Kircher, Moritz F.; de la Zerda, Adam; Zavaleta, Cristina L; Jokerst, Jesse V.; Mellinghoff, Ingo K.; Gambhir, Sanjiv S; Sinclair, Robert

    2014-01-01

    The growing use of nanoparticles in biomedical applications, including cancer diagnosis and treatment, demands the capability to exactly locate them within complex biological systems. In this work a correlative optical and scanning electron microscopy technique was developed to locate and observe multi-modal gold core nanoparticle accumulation in brain tumor models. Entire brain sections from mice containing orthotopic brain tumors injected intravenously with nanoparticles were imaged using both optical microscopy to identify the brain tumor, and scanning electron microscopy to identify the individual nanoparticles. Gold-based nanoparticles were readily identified in the scanning electron microscope using backscattered electron imaging as bright spots against a darker background. This information was then correlated to determine the exact location of the nanoparticles within the brain tissue. The nanoparticles were located only in areas that contained tumor cells, and not in the surrounding healthy brain tissue. This correlative technique provides a powerful method to relate the macro- and micro-scale features visible in light microscopy with the nanoscale features resolvable in scanning electron microscopy. PMID:25464144

  5. A correlative optical microscopy and scanning electron microscopy approach to locating nanoparticles in brain tumors.

    PubMed

    Kempen, Paul J; Kircher, Moritz F; de la Zerda, Adam; Zavaleta, Cristina L; Jokerst, Jesse V; Mellinghoff, Ingo K; Gambhir, Sanjiv S; Sinclair, Robert

    2015-01-01

    The growing use of nanoparticles in biomedical applications, including cancer diagnosis and treatment, demands the capability to exactly locate them within complex biological systems. In this work a correlative optical and scanning electron microscopy technique was developed to locate and observe multi-modal gold core nanoparticle accumulation in brain tumor models. Entire brain sections from mice containing orthotopic brain tumors injected intravenously with nanoparticles were imaged using both optical microscopy to identify the brain tumor, and scanning electron microscopy to identify the individual nanoparticles. Gold-based nanoparticles were readily identified in the scanning electron microscope using backscattered electron imaging as bright spots against a darker background. This information was then correlated to determine the exact location of the nanoparticles within the brain tissue. The nanoparticles were located only in areas that contained tumor cells, and not in the surrounding healthy brain tissue. This correlative technique provides a powerful method to relate the macro- and micro-scale features visible in light microscopy with the nanoscale features resolvable in scanning electron microscopy.

  6. Tip/tilt-compensated through-focus scanning optical microscopy

    NASA Astrophysics Data System (ADS)

    Lee, Jun Ho; Park, Jun Hyung; Jeong, Dohwan; Shin, Eun Ji; Park, Chris

    2016-11-01

    Through-Focus Optical Microscopy (TSOM), with nanometer scale lateral and vertical sensitivity matching those of scanning electron microscopy, has been demonstrated to be utilized for 3D inspection and metrology. There have been sensitivity and instability issues in acquiring through-focus images because TSOM 3D information is indirectly extracted by differentiating a target TSOM image from reference TSOM images. This paper first reports on the optical axis instability that occurs during the scanning process of TSOM when implemented in an existing patterned wafer inspection tool by moving the wafer plane; this is followed by quantitative confirmation of the optical/mechanical instability using a new TSOM tool on an optical bench with a Shack-Hartmann wavefront sensor and a tip/tilt sensor. Then, this paper proposes two tip/tilt compensated TSOM optical acquisition methods that can be applied with adaptive optics. The first method simply adopts a tip/tilt mirror with a quad cell in a simple closed loop, while the second method adopts a highorder deformable mirror with a Shack-Hartmann sensor. The second method is able to correct high-order residual aberrations as well as to perform through-focus scanning without z-axis movement, while the first method is easier to implement in pre-existing wafer inspection systems with only minor modification.

  7. Advances in transmission x-ray optics

    SciTech Connect

    Ceglio, N.M.

    1983-01-01

    Recent developments in x-ray optics are reviewed. Specific advances in coded aperture imaging, zone plate lens fabrication, time and space resolved spectroscopy, and CCD x-ray detection are discussed.

  8. Advances in high-speed low-latency communications for nanopositioning in advanced microscopy

    NASA Astrophysics Data System (ADS)

    Jordan, Scott C.

    2012-06-01

    We present a comparison of classical and recently developed communications interfacing technologies relevant to scanned imaging. We adopt an applications perspective, with a focus on interfacing techniques as enablers for enhanced resolution, speed, stability, information density or similar benefits. A wealth of such applications have emerged, ranging from nanoscale-stabilized force microscopy yielding 100X resolution improvement thanks to leveraging the latest in interfacing capabilities, to novel approaches in analog interfacing which improve data density and DAC resolution by several orders of magnitude. Our intent is to provide tools to understand, select and implement advanced interfacing to take applications to the next level. We have entered an era in which new interfacing techniques are enablers, in their own right, for novel imaging techniques. For example, clever leveraging of new interfacing technologies has yielded nanoscale stabilization and atomic-force microscopy (AFM) resolution enhancement. To assist in choosing and implementing interfacing strategies that maximize performance and enable new capabilities, we review available interfaces such as USB2, GPIB and Ethernet against the specific needs of positioning for the scanned-imaging community. We spotlight recent developments such as LabVIEW FPGA, which allows non-specialists to quickly devise custom logic and interfaces of unprecedentedly high performance and parallelism. Notable applications are reviewed, including a clever amalgamation of AFM and optical tweezers and a picometer-scaleaccuracy interferometer devised for ultrafine positioning validation. We note the Serial Peripheral Interface (SPI), emerging as a high-speed/low-latency instrumentation interface. The utility of instrument-specific parallel (PIO) and TTL sync/trigger (DIO) interfaces is also discussed. Requirements of tracking and autofocus are reviewed against the time-critical needs of typical applications (to avoid, for example

  9. In vivo switchable optical- and acoustic-resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Jeon, Seungwan; Kim, Jaewoo; Kim, Chulhong

    2016-03-01

    Photoacoustic microscopy (PAM) provides high resolution and large penetration depth by utilizing the high optical sensitivity and low scattering of ultrasound. Hybrid PAM systems can be classified into two categories: opticalresolution photoacoustic microscopy (OR-PAM) and acoustic-resolution photoacoustic microscopy (AR-PAM). ORPAM provides a very high lateral resolution with a strong optical focus, but the penetration depth is limited to one optical transport mean free path. AR-PAM provides a relatively greater penetration depth using diffused light in biological tissues. The resolution of AR-PAM is determined by its ultrasonic parameters. In this study, we performed an in vivo testing of a switchable OR-/AR-PAM system. In this system, two modes can be switched by changing its collimator lens and optical fiber. The lateral resolution of OR-PAM was measured using a resolution test target, and the full width at half maximum (FWHM) of the edge spread function was 2.5 μm. To calculate the lateral resolution of ARPAM, a 6-μm-diameter carbon fiber was used, and the FWHM of the line spread function was 80.2 μm. We successfully demonstrated the multiscale imaging capability of the switchable OR-/AR-PAM system by visualizing microvascular networks in mouse ears, brain, legs, skin, and eyes.

  10. Sensorless adaptive optics implementation in widefield optical sectioning microscopy inside in vivo Drosophila brain

    NASA Astrophysics Data System (ADS)

    Pedrazzani, Mélanie; Loriette, Vincent; Tchenio, Paul; Benrezzak, Sakina; Nutarelli, Daniele; Fragola, Alexandra

    2016-03-01

    We present an implementation of a sensorless adaptive optics loop in a widefield fluorescence microscope. This setup is designed to compensate for aberrations induced by the sample on both excitation and emission pathways. It allows fast optical sectioning inside a living Drosophila brain. We present a detailed characterization of the system performances. We prove that the gain brought to optical sectioning by realizing structured illumination microscopy with adaptive optics down to 50 μm deep inside living Drosophila brain.

  11. Sensorless adaptive optics implementation in widefield optical sectioning microscopy inside in vivo Drosophila brain.

    PubMed

    Pedrazzani, Mélanie; Loriette, Vincent; Tchenio, Paul; Benrezzak, Sakina; Nutarelli, Daniele; Fragola, Alexandra

    2016-03-01

    We present an implementation of a sensorless adaptive optics loop in a widefield fluorescence microscope. This setup is designed to compensate for aberrations induced by the sample on both excitation and emission pathways. It allows fast optical sectioning inside a living Drosophila brain. We present a detailed characterization of the system performances. We prove that the gain brought to optical sectioning by realizing structured illumination microscopy with adaptive optics down to 50 μm deep inside living Drosophila brain.

  12. Mosaic acquisition and processing for optical-resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Shao, Peng; Shi, Wei; Chee, Ryan K. W.; Zemp, Roger J.

    2012-08-01

    In optical-resolution photo-acoustic microscopy (OR-PAM), data acquisition time is limited by both laser pulse repetition rate (PRR) and scanning speed. Optical-scanning offers high speed, but limited, field of view determined by ultrasound transducer sensitivity. In this paper, we propose a hybrid optical and mechanical-scanning OR-PAM system with mosaic data acquisition and processing. The system employs fast-scanning mirrors and a diode-pumped, nanosecond-pulsed, Ytterbium-doped, 532-nm fiber laser with PRR up to 600 kHz. Data from a sequence of image mosaic patches is acquired systematically, at predetermined mechanical scanning locations, with optical scanning. After all imaging locations are covered, a large panoramic scene is generated by stitching the mosaic patches together. Our proposed system is proven to be at least 20 times faster than previous reported OR-PAM systems.

  13. Advanced Electro-Optic Surety Devices

    SciTech Connect

    Watterson, C.E.

    1997-05-01

    The Advanced Electro-Optic Surety Devices project was initiated in march 1991 to support design laboratory guidance on electro-optic device packaging and evaluation. Sandia National Laboratory requested AlliedSignal Inc., Kansas City Division (KCD), to prepare for future packaging efforts in electro-optic integrated circuits. Los Alamos National Laboratory requested the evaluation of electro-optic waveguide devices for nuclear surety applications. New packaging techniques involving multiple fiber optic alignment and attachment, binary lens array development, silicon V-groove etching, and flip chip bonding were requested. Hermetic sealing of the electro-optic hybrid and submicron alignment of optical components present new challenges to be resolved. A 10-channel electro-optic modulator and laser amplifier were evaluated for potential surety applications.

  14. Invited Review Article: Advanced light microscopy for biological space research

    NASA Astrophysics Data System (ADS)

    De Vos, Winnok H.; Beghuin, Didier; Schwarz, Christian J.; Jones, David B.; van Loon, Jack J. W. A.; Bereiter-Hahn, Juergen; Stelzer, Ernst H. K.

    2014-10-01

    As commercial space flights have become feasible and long-term extraterrestrial missions are planned, it is imperative that the impact of space travel and the space environment on human physiology be thoroughly characterized. Scrutinizing the effects of potentially detrimental factors such as ionizing radiation and microgravity at the cellular and tissue level demands adequate visualization technology. Advanced light microscopy (ALM) is the leading tool for non-destructive structural and functional investigation of static as well as dynamic biological systems. In recent years, technological developments and advances in photochemistry and genetic engineering have boosted all aspects of resolution, readout and throughput, rendering ALM ideally suited for biological space research. While various microscopy-based studies have addressed cellular response to space-related environmental stressors, biological endpoints have typically been determined only after the mission, leaving an experimental gap that is prone to bias results. An on-board, real-time microscopical monitoring device can bridge this gap. Breadboards and even fully operational microscope setups have been conceived, but they need to be rendered more compact and versatile. Most importantly, they must allow addressing the impact of gravity, or the lack thereof, on physiologically relevant biological systems in space and in ground-based simulations. In order to delineate the essential functionalities for such a system, we have reviewed the pending questions in space science, the relevant biological model systems, and the state-of-the art in ALM. Based on a rigorous trade-off, in which we recognize the relevance of multi-cellular systems and the cellular microenvironment, we propose a compact, but flexible concept for space-related cell biological research that is based on light sheet microscopy.

  15. Invited Review Article: Advanced light microscopy for biological space research

    SciTech Connect

    De Vos, Winnok H.; Beghuin, Didier; Schwarz, Christian J.; Jones, David B.; Loon, Jack J. W. A. van

    2014-10-15

    As commercial space flights have become feasible and long-term extraterrestrial missions are planned, it is imperative that the impact of space travel and the space environment on human physiology be thoroughly characterized. Scrutinizing the effects of potentially detrimental factors such as ionizing radiation and microgravity at the cellular and tissue level demands adequate visualization technology. Advanced light microscopy (ALM) is the leading tool for non-destructive structural and functional investigation of static as well as dynamic biological systems. In recent years, technological developments and advances in photochemistry and genetic engineering have boosted all aspects of resolution, readout and throughput, rendering ALM ideally suited for biological space research. While various microscopy-based studies have addressed cellular response to space-related environmental stressors, biological endpoints have typically been determined only after the mission, leaving an experimental gap that is prone to bias results. An on-board, real-time microscopical monitoring device can bridge this gap. Breadboards and even fully operational microscope setups have been conceived, but they need to be rendered more compact and versatile. Most importantly, they must allow addressing the impact of gravity, or the lack thereof, on physiologically relevant biological systems in space and in ground-based simulations. In order to delineate the essential functionalities for such a system, we have reviewed the pending questions in space science, the relevant biological model systems, and the state-of-the art in ALM. Based on a rigorous trade-off, in which we recognize the relevance of multi-cellular systems and the cellular microenvironment, we propose a compact, but flexible concept for space-related cell biological research that is based on light sheet microscopy.

  16. Invited review article: Advanced light microscopy for biological space research.

    PubMed

    De Vos, Winnok H; Beghuin, Didier; Schwarz, Christian J; Jones, David B; van Loon, Jack J W A; Bereiter-Hahn, Juergen; Stelzer, Ernst H K

    2014-10-01

    As commercial space flights have become feasible and long-term extraterrestrial missions are planned, it is imperative that the impact of space travel and the space environment on human physiology be thoroughly characterized. Scrutinizing the effects of potentially detrimental factors such as ionizing radiation and microgravity at the cellular and tissue level demands adequate visualization technology. Advanced light microscopy (ALM) is the leading tool for non-destructive structural and functional investigation of static as well as dynamic biological systems. In recent years, technological developments and advances in photochemistry and genetic engineering have boosted all aspects of resolution, readout and throughput, rendering ALM ideally suited for biological space research. While various microscopy-based studies have addressed cellular response to space-related environmental stressors, biological endpoints have typically been determined only after the mission, leaving an experimental gap that is prone to bias results. An on-board, real-time microscopical monitoring device can bridge this gap. Breadboards and even fully operational microscope setups have been conceived, but they need to be rendered more compact and versatile. Most importantly, they must allow addressing the impact of gravity, or the lack thereof, on physiologically relevant biological systems in space and in ground-based simulations. In order to delineate the essential functionalities for such a system, we have reviewed the pending questions in space science, the relevant biological model systems, and the state-of-the art in ALM. Based on a rigorous trade-off, in which we recognize the relevance of multi-cellular systems and the cellular microenvironment, we propose a compact, but flexible concept for space-related cell biological research that is based on light sheet microscopy.

  17. Holographic fluorescence microscopy with incoherent digital holographic adaptive optics.

    PubMed

    Jang, Changwon; Kim, Jonghyun; Clark, David C; Lee, Seungjae; Lee, Byoungho; Kim, Myung K

    2015-01-01

    Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: a wavefront sensor, wavefront corrector, and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, for example, lenslet arrays for sensing or multiactuator deformable mirrors for correcting. We have previously introduced an alternate approach based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile are possible not only with conventional coherent digital holography, but also with a new type of digital holography using incoherent light: selfinterference incoherent digital holography (SIDH). The SIDH generates a complex—i.e., amplitude plus phase—hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. Adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.

  18. Holographic fluorescence microscopy with incoherent digital holographic adaptive optics

    NASA Astrophysics Data System (ADS)

    Jang, Changwon; Kim, Jonghyun; Clark, David C.; Lee, Seungjae; Lee, Byoungho; Kim, Myung K.

    2015-11-01

    Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: a wavefront sensor, wavefront corrector, and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, for example, lenslet arrays for sensing or multiactuator deformable mirrors for correcting. We have previously introduced an alternate approach based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile are possible not only with conventional coherent digital holography, but also with a new type of digital holography using incoherent light: self­interference incoherent digital holography (SIDH). The SIDH generates a complex-i.e., amplitude plus phase-hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. Adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.

  19. Tip-enhanced near-field optical microscopy

    PubMed Central

    Mauser, Nina; Hartschuh, Achim

    2013-01-01

    Tip-enhanced near-field optical microscopy (TENOM) is a scanning probe technique capable of providing a broad range of spectroscopic information on single objects and structured surfaces at nanometer spatial resolution and with highest detection sensitivity. In this review, we first illustrate the physical principle of TENOM that utilizes the antenna function of a sharp probe to efficiently couple light to excitations on nanometer length scales. We then discuss the antenna-induced enhancement of different optical sample responses including Raman scattering, fluorescence, generation of photocurrent and electroluminescence. Different experimental realizations are presented and several recent examples that demonstrate the capabilities of the technique are reviewed. PMID:24100541

  20. Noise analysis for through-focus scanning optical microscopy

    PubMed Central

    Attota, Ravikiran

    2016-01-01

    A systematic noise-analysis study for optimizing data collection and data processing parameters for through-focus scanning optical microscopy (TSOM) is presented. TSOM is a three-dimensional shape metrology method that can achieve sub-nanometer measurement sensitivity by analyzing sets of images acquired through-focus using a conventional optical microscope. We show that best balance between signal-to-noise performance and acquisition time can be achieved by judicious spatial averaging. Correct background-signal subtraction of the imaging-system inhomogeneities is also critical, as well as careful alignment of the constituent images in the case of differential TSOM analysis. PMID:26872178

  1. All-optically integrated multimodality imaging system: combined photoacoustic microscopy, optical coherence tomography, and fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Chen, Zhongjiang; Yang, Sihua; Xing, Da

    2016-10-01

    We have developed a multimodality imaging system by optically integrating all-optical photoacoustic microscopy (AOPAM), optical coherence tomography (OCT) and fluorescence microscopy (FLM) to provide complementary information including optical absorption, optical back-scattering and fluorescence contrast of biological tissue. By sharing the same low-coherence Michelson interferometer, AOPAM and OCT could be organically optically combined to obtain the absorption and scattering information of the biological tissues. Also, owing to using the same laser source and objective lens, intrinsically registered photoacoustic and fluorescence signals are obtained to present the radiative and nonradiative transition process of absorption. Simultaneously photoacoustic angiography, tissue structure and fluorescence molecular in vivo images of mouse ear were acquired to demonstrate the capabilities of the optically integrated trimodality imaging system, which can present more information to study tumor angiogenesis, vasculature, anatomical structure and microenvironments in vivo.

  2. Nonlinear optical microscopy for investigation of gastrointestinal lesions

    NASA Astrophysics Data System (ADS)

    Genova, Ts.; Borisova, E.; Stanciu, G.; Tranca, D.; Terziev, I.; Penkov, N.; Vladimirov, B.; Lomova, M.; Semyachkina-Glushkovskaya, O.; Avramov, L.

    2016-01-01

    The standard procedure for cancer detection includes rigorous biopsy protocols, which are costly and time consuming; also the accuracy of the current diagnostic procedure relays entirely on the physician's experience and it is limited by the high probability of miss rates. Therefore new sensitive diagnostic modalities for analysis of biopsy tissue samples or on site, in vivo microscopy tissue examination, are necessary. In this study we present an investigation using nonlinear microscopy techniques for histological sections from biopsy tissue samples analysis. The samples were routinely processed for histological analysis and during the standard sampling the tissue slices were stained with hematoxylin and eosin dyes. The application of nonlinear microscopy techniques, such as two photon excitation fluorescence microscopy and second harmonic generation microscopy in biomedical research for cancer diagnosis has been vastly expanding in the last few years. Two-photon excitation fluorescence microscopy is based on a non-linear optical effect of simultaneously absorption of two photons, thus achieves excited state of the absorbing molecule with energy corresponding to the sum of the energies of two incident photons. This method allows for using an excitation wavelength which is double the typically required one for excitation of diagnostically valuable endogenous fluorophores. This results in more efficient depth penetration of the longer wavelength light in the tissue. The second harmonic generation microscopy is based on the principle of the non-linear susceptibility in noncentrosymmetric structures; such structures in the tissue are formed mainly by the collagen fibers. After excitation with near-infrared photons with wavelength λ of the collagen structures, photons with wavelength 1/2 λ are emitted - this corresponding to the second harmonic of the excitation beam's frequency. The applied nonlinear microscopy techniques are suitable for detection and

  3. The study of plant tissue by optical coherent microscopy method

    NASA Astrophysics Data System (ADS)

    Chirskaya, V. V.; Margaryants, N. B.; Zhukova, E. V.

    2016-08-01

    The article presents the results of application of the optical coherent microscopy technique using a high-resolution automatic Linnik interference microscope to study the structure of plant tissues exemplified by surface periderm layers of a tuberous nightshade (solánum tuberosum) bulb. The results of 3D visualization of the structure of the sample under examination are provided. Scanning depth was 32 µm, with axial and lateral resolution of the device 1 µm.

  4. Cytology 3D structure formation based on optical microscopy images

    NASA Astrophysics Data System (ADS)

    Pronichev, A. N.; Polyakov, E. V.; Shabalova, I. P.; Djangirova, T. V.; Zaitsev, S. M.

    2017-01-01

    The article the article is devoted to optimization of the parameters of imaging of biological preparations in optical microscopy using a multispectral camera in visible range of electromagnetic radiation. A model for the image forming of virtual preparations was proposed. The optimum number of layers was determined for the object scan in depth and holistic perception of its switching according to the results of the experiment.

  5. Advanced optical disk storage technology

    NASA Technical Reports Server (NTRS)

    Haritatos, Fred N.

    1996-01-01

    There is a growing need within the Air Force for more and better data storage solutions. Rome Laboratory, the Air Force's Center of Excellence for C3I technology, has sponsored the development of a number of operational prototypes to deal with this growing problem. This paper will briefly summarize the various prototype developments with examples of full mil-spec and best commercial practice. These prototypes have successfully operated under severe space, airborne and tactical field environments. From a technical perspective these prototypes have included rewritable optical media ranging from a 5.25-inch diameter format up to the 14-inch diameter disk format. Implementations include an airborne sensor recorder, a deployable optical jukebox and a parallel array of optical disk drives. They include stand-alone peripheral devices to centralized, hierarchical storage management systems for distributed data processing applications.

  6. Liquid lens: advances in adaptive optics

    NASA Astrophysics Data System (ADS)

    Casey, Shawn Patrick

    2010-12-01

    'Liquid lens' technologies promise significant advancements in machine vision and optical communications systems. Adaptations for machine vision, human vision correction, and optical communications are used to exemplify the versatile nature of this technology. Utilization of liquid lens elements allows the cost effective implementation of optical velocity measurement. The project consists of a custom image processor, camera, and interface. The images are passed into customized pattern recognition and optical character recognition algorithms. A single camera would be used for both speed detection and object recognition.

  7. Using electron microscopy to calculate optical properties of biological samples.

    PubMed

    Wu, Wenli; Radosevich, Andrew J; Eshein, Adam; Nguyen, The-Quyen; Yi, Ji; Cherkezyan, Lusik; Roy, Hemant K; Szleifer, Igal; Backman, Vadim

    2016-11-01

    The microscopic structural origins of optical properties in biological media are still not fully understood. Better understanding these origins can serve to improve the utility of existing techniques and facilitate the discovery of other novel techniques. We propose a novel analysis technique using electron microscopy (EM) to calculate optical properties of specific biological structures. This method is demonstrated with images of human epithelial colon cell nuclei. The spectrum of anisotropy factor g, the phase function and the shape factor D of the nuclei are calculated. The results show strong agreement with an independent study. This method provides a new way to extract the true phase function of biological samples and provides an independent validation for optical property measurement techniques.

  8. Multispectral photoacoustic microscopy based on an optical-acoustic objective.

    PubMed

    Cao, Rui; Kilroy, Joseph P; Ning, Bo; Wang, Tianxiong; Hossack, John A; Hu, Song

    2015-06-01

    We have developed reflection-mode multispectral photoacoustic microscopy (PAM) based on a novel optical-acoustic objective that integrates a customized ultrasonic transducer and a commercial reflective microscope objective into one solid piece. This technical innovation provides zero chromatic aberration and convenient confocal alignment of the optical excitation and acoustic detection. With a wavelength-tunable optical-parametric-oscillator laser, we have demonstrated multispectral PAM over an ultrabroad spectral range of 270-1300 nm. A near-constant lateral resolution of ∼2.8 μm is achieved experimentally. Capitalizing on the consistent performance over the ultraviolet, visible, and near-infrared range, multispectral PAM enables label-free concurrent imaging of cell nucleus (DNA/RNA contrast at 270 nm), blood vessel (hemoglobin contrast at 532 nm), and sebaceous gland (lipid contrast at 1260 nm) at the same spatial scale in a living mouse ear.

  9. Super-resolution optical microscopy of lipid plasma membrane dynamics.

    PubMed

    Eggeling, Christian

    2015-01-01

    Plasma membrane dynamics are an important ruler of cellular activity, particularly through the interaction and diffusion dynamics of membrane-embedded proteins and lipids. FCS (fluorescence correlation spectroscopy) on an optical (confocal) microscope is a popular tool for investigating such dynamics. Unfortunately, its full applicability is constrained by the limited spatial resolution of a conventional optical microscope. The present chapter depicts the combination of optical super-resolution STED (stimulated emission depletion) microscopy with FCS, and why it is an important tool for investigating molecular membrane dynamics in living cells. Compared with conventional FCS, the STED-FCS approach demonstrates an improved possibility to distinguish free from anomalous molecular diffusion, and thus to give new insights into lipid-protein interactions and the traditional lipid 'raft' theory.

  10. Using electron microscopy to calculate optical properties of biological samples

    PubMed Central

    Wu, Wenli; Radosevich, Andrew J.; Eshein, Adam; Nguyen, The-Quyen; Yi, Ji; Cherkezyan, Lusik; Roy, Hemant K.; Szleifer, Igal; Backman, Vadim

    2016-01-01

    The microscopic structural origins of optical properties in biological media are still not fully understood. Better understanding these origins can serve to improve the utility of existing techniques and facilitate the discovery of other novel techniques. We propose a novel analysis technique using electron microscopy (EM) to calculate optical properties of specific biological structures. This method is demonstrated with images of human epithelial colon cell nuclei. The spectrum of anisotropy factor g, the phase function and the shape factor D of the nuclei are calculated. The results show strong agreement with an independent study. This method provides a new way to extract the true phase function of biological samples and provides an independent validation for optical property measurement techniques. PMID:27896013

  11. Design of a fiber-optic multiphoton microscopy handheld probe

    PubMed Central

    Zhao, Yuan; Sheng, Mingyu; Huang, Lin; Tang, Shuo

    2016-01-01

    We have developed a fiber-optic multiphoton microscopy (MPM) system with handheld probe using femtosecond fiber laser. Here we present the detailed optical design and analysis of the handheld probe. The optical systems using Lightpath 352140 and 352150 as objective lens were analyzed. A custom objective module that includes Lightpath 355392 and two customized corrective lenses was designed. Their performances were compared by wavefront error, field curvature, astigmatism, F-θ error, and tolerance in Zemax simulation. Tolerance analysis predicted the focal spot size to be 1.13, 1.19 and 0.83 µm, respectively. Lightpath 352140 and 352150 were implemented in experiment and the measured lateral resolution was 1.22 and 1.3 µm, respectively, which matched with the prediction. MPM imaging by the handheld probe were conducted on leaf, fish scale and rat tail tendon. The MPM resolution can potentially be improved by the custom objective module. PMID:27699109

  12. Near-infrared optical-resolution photoacoustic microscopy.

    PubMed

    Hai, Pengfei; Yao, Junjie; Maslov, Konstantin I; Zhou, Yong; Wang, Lihong V

    2014-09-01

    Compared with visible light (380-700 nm), near-infrared light (700-1400 nm) undergoes weaker optical attenuation in biological tissue; thus, it can penetrate deeper. Herein, we demonstrate near-infrared optical-resolution photoacoustic microscopy (NIR-OR-PAM) with 1046 nm illumination. A penetration depth of 3.2 mm was achieved in chicken breast tissue ex vivo using optical fluence within the American National Standards Institute (ANSI) limit (100  mJ/cm2). Beyond ∼0.6  mm deep in chicken breast tissue, NIR-OR-PAM has shown finer resolution than the visible counterpart with 570 nm illumination. The deep imaging capability of NIR-OR-PAM was validated in both a mouse ear and a mouse brain. NIR-OR-PAM of possible lipid contrast was explored as well.

  13. Advanced analytical electron microscopy for alkali-ion batteries

    DOE PAGES

    Qian, Danna; Ma, Cheng; Meng, Ying Shirley; ...

    2015-01-01

    Lithium-ion batteries are a leading candidate for electric vehicle and smart grid applications. However, further optimizations of the energy/power density, coulombic efficiency and cycle life are still needed, and this requires a thorough understanding of the dynamic evolution of each component and their synergistic behaviors during battery operation. With the capability of resolving the structure and chemistry at an atomic resolution, advanced analytical transmission electron microscopy (AEM) is an ideal technique for this task. The present review paper focuses on recent contributions of this important technique to the fundamental understanding of the electrochemical processes of battery materials. A detailed reviewmore » of both static (ex situ) and real-time (in situ) studies will be given, and issues that still need to be addressed will be discussed.« less

  14. Advanced analytical electron microscopy for alkali-ion batteries

    SciTech Connect

    Qian, Danna; Ma, Cheng; Meng, Ying Shirley; More, Karren; Chi, Miaofang

    2015-01-01

    Lithium-ion batteries are a leading candidate for electric vehicle and smart grid applications. However, further optimizations of the energy/power density, coulombic efficiency and cycle life are still needed, and this requires a thorough understanding of the dynamic evolution of each component and their synergistic behaviors during battery operation. With the capability of resolving the structure and chemistry at an atomic resolution, advanced analytical transmission electron microscopy (AEM) is an ideal technique for this task. The present review paper focuses on recent contributions of this important technique to the fundamental understanding of the electrochemical processes of battery materials. A detailed review of both static (ex situ) and real-time (in situ) studies will be given, and issues that still need to be addressed will be discussed.

  15. Holographic fluorescence microscopy with incoherent digital holographic adaptive optics

    NASA Astrophysics Data System (ADS)

    Jang, Changwon; Kim, Jonghyun; Clark, David C.; Lee, Byoungho; Kim, Myung K.

    2015-03-01

    Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: wavefront sensor, wavefront corrector and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, e.g., lenslet arrays for sensing or multi-acuator deformable mirrors for correcting. We have previously introduced an alternate approach to adaptive optics based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile is possible not only with the conventional coherent type of digital holography, but also with a new type of digital holography using incoherent light: self-interference incoherent digital holography (SIDH). The SIDH generates complex - i.e. amplitude plus phase - hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using a guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. The adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.

  16. Advanced fertility diagnosis in stallion semen using transmission electron microscopy.

    PubMed

    Pesch, Sandra; Bostedt, Hartwig; Failing, Klaus; Bergmann, Martin

    2006-02-01

    Routine semen analysis of stallions is based on light microscopy (LM). However, there are still a number of animals that are subfertile or even infertile not being identified with conventional semen analysis. The objective of this study was to investigate the suitability of transmission electron microscopy (TEM) for advanced fertility diagnosis in stallion. We examined ejaculates of 46 stallions with known fertility. Animals were divided into three different groups: group 1, fertile stallions (pregnant mares> or =70%, n=29); group 2, subfertile stallions (pregnant mares 10-69%, n=14); group 3, infertile stallions (pregnant mares<10%, n=3). Ejaculates were collected in spring 2002. Conventional semen analysis (volume, sperm concentration, motility, live:dead ratio and percentage of morphologically normal sperm) was immediately performed after semen collection. Ultrastructural analysis included the evaluation of 200 acrosomes, heads, midpieces and cross-sections of tails as well as 100 longitudinal sections of tails from every ejaculate. Using LM, we found a significant increase of morphological deviations from 24.5% (x ) in group 1 to 34.5% in group 2 and 73.5% in group 3. Using TEM, we found a significant increase of detached acrosomes from 6.1% in group 1 to 7.6% in group 2 and 21.4% in group 3. Deviations in tubule pattern were also increased (but not significant) from 2.7% in fertile and 2.8% in subfertile to 11.4% in infertile stallions as well as multiple tails from 1.9% in fertile to 2.0% in subfertile and 8.9% in infertile. Our data indicate that TEM is suitable for advanced fertility diagnostic in stallions, giving a connection between fertility and morphology. It suggests that the most likely reason for sub- and infertility in stallion in case of increased LM pathomorphology of semen are acrosomal alterations, especially detached acrosomes.

  17. Advanced light microscopy core facilities: Balancing service, science and career

    PubMed Central

    Hartmann, Hella; Reymann, Jürgen; Ansari, Nariman; Utz, Nadine; Fried, Hans‐Ulrich; Kukat, Christian; Peychl, Jan; Liebig, Christian; Terjung, Stefan; Laketa, Vibor; Sporbert, Anje; Weidtkamp‐Peters, Stefanie; Schauss, Astrid; Zuschratter, Werner; Avilov, Sergiy

    2016-01-01

    ABSTRACT Core Facilities (CF) for advanced light microscopy (ALM) have become indispensable support units for research in the life sciences. Their organizational structure and technical characteristics are quite diverse, although the tasks they pursue and the services they offer are similar. Therefore, throughout Europe, scientists from ALM‐CFs are forming networks to promote interactions and discuss best practice models. Here, we present recommendations for ALM‐CF operations elaborated by the workgroups of the German network of ALM‐CFs, German Bio‐Imaging (GerBI). We address technical aspects of CF planning and instrument maintainance, give advice on the organization and management of an ALM‐CF, propose a scheme for the training of CF users, and provide an overview of current resources for image processing and analysis. Further, we elaborate on the new challenges and opportunities for professional development and careers created by CFs. While some information specifically refers to the German academic system, most of the content of this article is of general interest for CFs in the life sciences. Microsc. Res. Tech. 79:463–479, 2016. © 2016 THE AUTHORS MICROSCOPY RESEARCH AND TECHNIQUE PUBLISHED BY WILEY PERIODICALS, INC. PMID:27040755

  18. Advances in optics for biotechnology, medicine and surgery.

    PubMed

    Hillman, Elizabeth M C; Elson, Daniel S; Bigio, Irving J; Levenson, Richard M; So, Peter T C

    2012-03-01

    The editors introduce the Biomedical Optics Express feature issue, "Advances in Optics for Biotechnology, Medicine and Surgery," which includes 12 contributions from attendees of the 2011 conference Advances in Optics for Biotechnology, Medicine and Surgery XII.

  19. Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications

    PubMed Central

    Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W.; Dokmeci, Mehmet Remzi; Boyden, Edward S.; Khademhosseini, Ali

    2016-01-01

    To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such “hybrid microscopy” methods—combining physical and optical magnifications—can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes (“mini-microscopes”), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics—a process we refer to as Expansion Mini-Microscopy (ExMM)—is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places. PMID:26975883

  20. Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications

    NASA Astrophysics Data System (ADS)

    Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W.; Dokmeci, Mehmet Remzi; Boyden, Edward S.; Khademhosseini, Ali

    2016-03-01

    To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such “hybrid microscopy” methods—combining physical and optical magnifications—can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes (“mini-microscopes”), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics—a process we refer to as Expansion Mini-Microscopy (ExMM)—is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places.

  1. Nano-scale measurement of biomolecules by optical microscopy and semiconductor nanoparticles

    PubMed Central

    Ichimura, Taro; Jin, Takashi; Fujita, Hideaki; Higuchi, Hideo; Watanabe, Tomonobu M.

    2014-01-01

    Over the past decade, great developments in optical microscopy have made this technology increasingly compatible with biological studies. Fluorescence microscopy has especially contributed to investigating the dynamic behaviors of live specimens and can now resolve objects with nanometer precision and resolution due to super-resolution imaging. Additionally, single particle tracking provides information on the dynamics of individual proteins at the nanometer scale both in vitro and in cells. Complementing advances in microscopy technologies has been the development of fluorescent probes. The quantum dot, a semi-conductor fluorescent nanoparticle, is particularly suitable for single particle tracking and super-resolution imaging. This article overviews the principles of single particle tracking and super resolution along with describing their application to the nanometer measurement/observation of biological systems when combined with quantum dot technologies. PMID:25120488

  2. Nano-scale measurement of biomolecules by optical microscopy and semiconductor nanoparticles.

    PubMed

    Ichimura, Taro; Jin, Takashi; Fujita, Hideaki; Higuchi, Hideo; Watanabe, Tomonobu M

    2014-01-01

    Over the past decade, great developments in optical microscopy have made this technology increasingly compatible with biological studies. Fluorescence microscopy has especially contributed to investigating the dynamic behaviors of live specimens and can now resolve objects with nanometer precision and resolution due to super-resolution imaging. Additionally, single particle tracking provides information on the dynamics of individual proteins at the nanometer scale both in vitro and in cells. Complementing advances in microscopy technologies has been the development of fluorescent probes. The quantum dot, a semi-conductor fluorescent nanoparticle, is particularly suitable for single particle tracking and super-resolution imaging. This article overviews the principles of single particle tracking and super resolution along with describing their application to the nanometer measurement/observation of biological systems when combined with quantum dot technologies.

  3. Optical-resolution photoacoustic microscopy of amyloid-β deposits in vivo

    NASA Astrophysics Data System (ADS)

    Hu, Song; Yan, Ping; Maslov, Konstantin; Lee, Jin-Moo; Wang, Lihong V.

    2010-02-01

    Advances in high-resolution imaging have permitted microscopic observations within the brains of living animals. Applied to Alzheimer's disease (AD) mouse models, multiphoton microscopy has opened a new window to study the real-time appearance and growth of amyloid plaques. Here, we report an alternative technology-optical-resolution photoacoustic microscopy (OR-PAM)-for in vivo imaging of amyloid plaques in a transgenic AD mouse model. In vivo validation using multiphoton microscopy shows that OR-PAM has sufficient sensitivity and spatial resolution to identify amyloid plaques in living brains. In addition, with dual-wavelength OR-PAM, the three-dimensional morphology of amyloid plaques and the surrounding microvasculature are imaged simultaneously through a cranial window. In vivo transcranial OR-PAM imaging of amyloid plaques is highly likely once the imaging parameters are optimized.

  4. Surface plasmon resonance microscopy: Achieving a quantitative optical response

    NASA Astrophysics Data System (ADS)

    Peterson, Alexander W.; Halter, Michael; Plant, Anne L.; Elliott, John T.

    2016-09-01

    Surface plasmon resonance (SPR) imaging allows real-time label-free imaging based on index of refraction and changes in index of refraction at an interface. Optical parameter analysis is achieved by application of the Fresnel model to SPR data typically taken by an instrument in a prism based figuration. We carry out SPR imaging on a microscope by launching light into a sample and collecting reflected light through a high numerical aperture microscope objective. The SPR microscope enables spatial resolution that approaches the diffraction limit and has a dynamic range that allows detection of subnanometer to submicrometer changes in thickness of biological material at a surface. However, unambiguous quantitative interpretation of SPR changes using the microscope system could not be achieved using the Fresnel model because of polarization dependent attenuation and optical aberration that occurs in the high numerical aperture objective. To overcome this problem, we demonstrate a model to correct for polarization diattenuation and optical aberrations in the SPR data and develop a procedure to calibrate reflectivity to index of refraction values. The calibration and correction strategy for quantitative analysis was validated by comparing the known indices of refraction of bulk materials with corrected SPR data interpreted with the Fresnel model. Subsequently, we applied our SPR microscopy method to evaluate the index of refraction for a series of polymer microspheres in aqueous media and validated the quality of the measurement with quantitative phase microscopy.

  5. Automated seeding-based nuclei segmentation in nonlinear optical microscopy.

    PubMed

    Medyukhina, Anna; Meyer, Tobias; Heuke, Sandro; Vogler, Nadine; Dietzek, Benjamin; Popp, Jürgen

    2013-10-01

    Nonlinear optical (NLO) microscopy based, e.g., on coherent anti-Stokes Raman scattering (CARS) or two-photon-excited fluorescence (TPEF) is a fast label-free imaging technique, with a great potential for biomedical applications. However, NLO microscopy as a diagnostic tool is still in its infancy; there is a lack of robust and durable nuclei segmentation methods capable of accurate image processing in cases of variable image contrast, nuclear density, and type of investigated tissue. Nonetheless, such algorithms specifically adapted to NLO microscopy present one prerequisite for the technology to be routinely used, e.g., in pathology or intraoperatively for surgical guidance. In this paper, we compare the applicability of different seeding and boundary detection methods to NLO microscopic images in order to develop an optimal seeding-based approach capable of accurate segmentation of both TPEF and CARS images. Among different methods, the Laplacian of Gaussian filter showed the best accuracy for the seeding of the image, while a modified seeded watershed segmentation was the most accurate in the task of boundary detection. The resulting combination of these methods followed by the verification of the detected nuclei performs high average sensitivity and specificity when applied to various types of NLO microscopy images.

  6. Super-resolution microscopy of single atoms in optical lattices

    NASA Astrophysics Data System (ADS)

    Alberti, Andrea; Robens, Carsten; Alt, Wolfgang; Brakhane, Stefan; Karski, Michał; Reimann, René; Widera, Artur; Meschede, Dieter

    2016-05-01

    We report on image processing techniques and experimental procedures to determine the lattice-site positions of single atoms in an optical lattice with high reliability, even for limited acquisition time or optical resolution. Determining the positions of atoms beyond the diffraction limit relies on parametric deconvolution in close analogy to methods employed in super-resolution microscopy. We develop a deconvolution method that makes effective use of the prior knowledge of the optical transfer function, noise properties, and discreteness of the optical lattice. We show that accurate knowledge of the image formation process enables a dramatic improvement on the localization reliability. This allows us to demonstrate super-resolution of the atoms’ position in closely packed ensembles where the separation between particles cannot be directly optically resolved. Furthermore, we demonstrate experimental methods to precisely reconstruct the point spread function with sub-pixel resolution from fluorescence images of single atoms, and we give a mathematical foundation thereof. We also discuss discretized image sampling in pixel detectors and provide a quantitative model of noise sources in electron multiplying CCD cameras. The techniques developed here are not only beneficial to neutral atom experiments, but could also be employed to improve the localization precision of trapped ions for ultra precise force sensing.

  7. Femtosecond Optics: Advanced Devices and Ultrafast Phenomena

    DTIC Science & Technology

    2007-05-31

    periodically poled lithium niobate (PPLN), which already represents a significant advance . Gain is given by G=0.25(1+ exp(gl)), where for 7 t2 PPLN, g...H. Sotobayashi, J.T. Gopinath, and E.P. Ippen, ൟ cm long Bi20 3-based EDFA for picosecond pulse amplification with 80 nm gain bandwidth," IEEE...will be minimized by keeping the data in the optical domain. Such all- optical networks require advanced photonic technologies for a variety of

  8. Quantitative interferometric microscopy cytometer based on regularized optical flow algorithm

    NASA Astrophysics Data System (ADS)

    Xue, Liang; Vargas, Javier; Wang, Shouyu; Li, Zhenhua; Liu, Fei

    2015-09-01

    Cell detections and analysis are important in various fields, such as medical observations and disease diagnoses. In order to analyze the cell parameters as well as observe the samples directly, in this paper, we present an improved quantitative interferometric microscopy cytometer, which can monitor the quantitative phase distributions of bio-samples and realize cellular parameter statistics. The proposed system is able to recover the phase imaging of biological samples in the expanded field of view via a regularized optical flow demodulation algorithm. This algorithm reconstructs the phase distribution with high accuracy with only two interferograms acquired at different time points simplifying the scanning system. Additionally, the method is totally automatic, and therefore it is convenient for establishing a quantitative phase cytometer. Moreover, the phase retrieval approach is robust against noise and background. Excitingly, red blood cells are readily investigated with the quantitative interferometric microscopy cytometer system.

  9. Direct measurement of the free energy by optical microscopy.

    PubMed

    Dullens, Roel P A; Aarts, Dirk G A L; Kegel, Willem K

    2006-01-17

    We report the direct measurement of thermodynamic properties of colloidal hard spheres by optical microscopy. By using confocal microscopy, we obtain three-dimensional snapshots of a colloidal hard-sphere suspension over a wide range of densities. From these snapshots, the available volume to insert an additional sphere and the surface area of that volume are determined, which are directly related to the thermodynamics of the system. This procedure enables us to measure in a direct and noninterfering way, in principle, all thermodynamic properties, here demonstrated for the pressure, the chemical potential, and the free-energy density of a colloidal hard-sphere suspension. The "visual" determination of thermodynamic quantities opens up the possibility to experimentally study the relation between thermodynamics and geometry in real space beyond the hard-sphere potential.

  10. Nonlinear optical microscopy improvement by focal-point axial modulation

    NASA Astrophysics Data System (ADS)

    Dashtabi, Mahdi Mozdoor; Massudi, Reza

    2016-05-01

    Among the most important challenges of microscopy-even more important than the resolution enhancement, especially in biological and neuroscience applications-is noninvasive and label-free imaging deeper into live scattering samples. However, the fundamental limitation on imaging depth is the signal-to-background ratio in scattering biological tissues. Here, using a vibrating microscope objective in conjunction with a lock-in amplifier, we demonstrate the background cancellation in imaging the samples surrounded by turbid and scattering media, which leads to more clear images deeper into the samples. Furthermore, this technique offers the localization and resolution enhancement as well as resolves ambiguities in signal interpretation, using a single-color laser. This technique is applicable to most nonlinear as well as some linear point-scanning optical microscopies.

  11. Assessment of fibrotic liver disease with multimodal nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Lu, Fake; Zheng, Wei; Tai, Dean C. S.; Lin, Jian; Yu, Hanry; Huang, Zhiwei

    2010-02-01

    Liver fibrosis is the excessive accumulation of extracellular matrix proteins such as collagens, which may result in cirrhosis, liver failure, and portal hypertension. In this study, we apply a multimodal nonlinear optical microscopy platform developed to investigate the fibrotic liver diseases in rat models established by performing bile duct ligation (BDL) surgery. The three nonlinear microscopy imaging modalities are implemented on the same sectioned tissues of diseased model sequentially: i.e., second harmonic generation (SHG) imaging quantifies the contents of the collagens, the two-photon excitation fluorescence (TPEF) imaging reveals the morphology of hepatic cells, while coherent anti-Stokes Raman scattering (CARS) imaging maps the distributions of fats or lipids quantitatively across the tissue. Our imaging results show that during the development of liver fibrosis (collagens) in BDL model, fatty liver disease also occurs. The aggregated concentrations of collagen and fat constituents in liver fibrosis model show a certain correlationship between each other.

  12. Scanning near-field optical microscopy: application to biological sciences

    NASA Astrophysics Data System (ADS)

    Lim, Tuan-Kay

    2001-12-01

    Recent developments in genetic engineering and medical informatics offer enormous potential for biotechnology. However, key enabling technologies, such as medical instrumentation and analytical tools, are required to support further research in this field. The scanning near-field optical microscopy (SNOM) is one of the key instruments for research in these areas. In this paper, we review the synergy of the SNOM with other technologies for the imaging and characterization of biological materials. Based on this review, the components and systems design parameters are summarized.

  13. Ultrafast Optical Microscopy of Single Monolayer Molybdenum Disulfide Flakes

    SciTech Connect

    Seo, Minah; Yamaguchi, Hisato; Mohite, Aditya D.; Boubanga-Tombet, Stephane; Blancon, Jean-Christophe; Najmaei, Sina; Ajayan, Pulickel M.; Lou, Jun; Taylor, Antoinette J.; Prasankumar, Rohit P.

    2016-02-15

    We performed ultrafast optical microscopy on single flakes of atomically thin CVD-grown molybdenum disulfide, using non-degenerate femtosecond pump-probe spectroscopy to excite and probe carriers above and below the indirect and direct band gaps. These measurements reveal the influence of layer thickness on carrier dynamics when probing near the band gap. Furthermore, fluence-dependent measurements indicate that carrier relaxation is primarily influenced by surface-related defect and trap states after above-bandgap photoexcitation. Furthermore, the ability to probe femtosecond carrier dynamics in individual flakes can thus give much insight into light-matter interactions in these two-dimensional nanosystems.

  14. Dark-field circular depolarization optical coherence microscopy

    PubMed Central

    Mehta, Kalpesh; Zhang, Pengfei; Yeo, Eugenia Li Ling; Kah, James Chen Yong; Chen, Nanguang

    2013-01-01

    Optical coherence microscopy (OCM) is a widely used structural imaging modality. To extend its application in molecular imaging, gold nanorods are widely used as contrast agents for OCM. However, they very often offer limited sensitivity as a result of poor signal to background ratio. Here we experimentally demonstrate that a novel OCM implementation based on dark-field circular depolarization detection can efficiently detect circularly depolarized signal from gold nanorods and at the same time efficiently suppress the background signals. This results into a significant improvement in signal to background ratio. PMID:24049689

  15. Ultrafast Optical Microscopy of Single Monolayer Molybdenum Disulfide Flakes

    PubMed Central

    Seo, Minah; Yamaguchi, Hisato; Mohite, Aditya D.; Boubanga-Tombet, Stephane; Blancon, Jean-Christophe; Najmaei, Sina; Ajayan, Pulickel M.; Lou, Jun; Taylor, Antoinette J.; Prasankumar, Rohit P.

    2016-01-01

    We have performed ultrafast optical microscopy on single flakes of atomically thin CVD-grown molybdenum disulfide, using non-degenerate femtosecond pump-probe spectroscopy to excite and probe carriers above and below the indirect and direct band gaps. These measurements reveal the influence of layer thickness on carrier dynamics when probing near the band gap. Furthermore, fluence-dependent measurements indicate that carrier relaxation is primarily influenced by surface-related defect and trap states after above-bandgap photoexcitation. The ability to probe femtosecond carrier dynamics in individual flakes can thus give much insight into light-matter interactions in these two-dimensional nanosystems. PMID:26876194

  16. Combined transmission and reflection optical microscopy of ice core sections

    NASA Astrophysics Data System (ADS)

    Binder, Tobias; Weikusat, Ilka; Kerst, Thomas; Eichler, Jan; Svensson, Anders; Bohleber, Pascal; Garbe, Christoph; Kipfstuhl, Sepp

    2013-04-01

    Microstructure analysis of ice cores is vital to understand the processes controlling the flow of ice on the microscale. To quantify the microstructural variability (and thus occurring processes) on centimeter, meter and kilometer scale along deep polar ice cores, a large number of sections has to be analyzed. In the last decade, two different methods have been applied: On the one hand, transmission optical microscopy of thin sections between crossed polarizers yields information on the distribution of crystal c-axes. On the other hand, reflection optical microscopy of polished and controlled sublimated section surfaces allows to characterize the high resolution properties of a single grain boundary, e.g. its length, shape or curvature. Based on a polar and an alpine ice core we applied both methods to the same set of sections. This enables us to combine all information on crystal orientation and (sub-)grain boundaries. In this contribution we introduce the method of combined transmission-polarization and reflection microscopy as well as an image processing framework for processing and matching both image types [1]. The information content of both analysis methods is limited and influenced by different types of artifacts. It is exemplary shown how the combination allows to compensate for deficiencies of one method. The gray values in images of the grain boundaries on polished ice core sections are influenced by the duration of surface sublimation and the energy/misorientation of the grain boundaries in the section. By combining these gray values with the misorientation obtained from the corresponding thin section imaged between crossed polarizers we try to validate the information content of gray values on the basis of large data sets. This approach is compared to X-ray Laue diffraction measurements (yielding full crystallographic orientation) which validated the sensitivity of the surface sublimation method [2]. As microscopy in transmission mode acquires volume

  17. Extending single-molecule microscopy using optical Fourier processing.

    PubMed

    Backer, Adam S; Moerner, W E

    2014-07-17

    This article surveys the recent application of optical Fourier processing to the long-established but still expanding field of single-molecule imaging and microscopy. A variety of single-molecule studies can benefit from the additional image information that can be obtained by modulating the Fourier, or pupil, plane of a widefield microscope. After briefly reviewing several current applications, we present a comprehensive and computationally efficient theoretical model for simulating single-molecule fluorescence as it propagates through an imaging system. Furthermore, we describe how phase/amplitude-modulating optics inserted in the imaging pathway may be modeled, especially at the Fourier plane. Finally, we discuss selected recent applications of Fourier processing methods to measure the orientation, depth, and rotational mobility of single fluorescent molecules.

  18. Optimization-based wavefront sensorless adaptive optics for multiphoton microscopy.

    PubMed

    Antonello, Jacopo; van Werkhoven, Tim; Verhaegen, Michel; Truong, Hoa H; Keller, Christoph U; Gerritsen, Hans C

    2014-06-01

    Optical aberrations have detrimental effects in multiphoton microscopy. These effects can be curtailed by implementing model-based wavefront sensorless adaptive optics, which only requires the addition of a wavefront shaping device, such as a deformable mirror (DM) to an existing microscope. The aberration correction is achieved by maximizing a suitable image quality metric. We implement a model-based aberration correction algorithm in a second-harmonic microscope. The tip, tilt, and defocus aberrations are removed from the basis functions used for the control of the DM, as these aberrations induce distortions in the acquired images. We compute the parameters of a quadratic polynomial that is used to model the image quality metric directly from experimental input-output measurements. Finally, we apply the aberration correction by maximizing the image quality metric using the least-squares estimate of the unknown aberration.

  19. Extending Single-Molecule Microscopy Using Optical Fourier Processing

    PubMed Central

    2015-01-01

    This article surveys the recent application of optical Fourier processing to the long-established but still expanding field of single-molecule imaging and microscopy. A variety of single-molecule studies can benefit from the additional image information that can be obtained by modulating the Fourier, or pupil, plane of a widefield microscope. After briefly reviewing several current applications, we present a comprehensive and computationally efficient theoretical model for simulating single-molecule fluorescence as it propagates through an imaging system. Furthermore, we describe how phase/amplitude-modulating optics inserted in the imaging pathway may be modeled, especially at the Fourier plane. Finally, we discuss selected recent applications of Fourier processing methods to measure the orientation, depth, and rotational mobility of single fluorescent molecules. PMID:24745862

  20. Optical digital microscopy for cyto- and hematological studies in vitro

    NASA Astrophysics Data System (ADS)

    Ganilova, Yu. A.; Dolmashkin, A. A.; Doubrovski, V. A.; Yanina, I. Yu.; Tuchin, V. V.

    2013-08-01

    The dependence of the spatial resolution and field of view of an optical microscope equipped with a CCD camera on the objective magnification has been experimentally investigated. Measurement of these characteristics has shown that a spatial resolution of 20-25 px/μm at a field of view of about 110 μm is quite realistic; this resolution is acceptable for a detailed study of the processes occurring in cell. It is proposed to expand the dynamic range of digital camera by measuring and approximating its light characteristics with subsequent plotting of the corresponding calibration curve. The biological objects of study were human adipose tissue cells, as well as erythrocytes and their immune complexes in human blood; both objects have been investigated in vitro. Application of optical digital microscopy for solving specific problems of cytology and hematology can be useful in both biomedical studies in experiments with objects of nonbiological origin.

  1. Freeform and advanced optics for ELT instrumentation

    NASA Astrophysics Data System (ADS)

    Geyl, Roland

    2016-07-01

    In this paper we share some recent work performed at REOSC in the domain of advanced optics for space and that is also directly applicable to astronomical instrumentation, e.g. for the Extremely Large Telescopes (ELT), the construction of which has already started. We present firstly the results of some design investigations performed on Three Mirror Anastigmat (TMA) imaging optics when using freeform optical surfaces clearly showing gain in performance (WFE, distortion, … ) or compactness of the optics. We separate smart freeform from more aggressive freeform offering increased level of gain in design performances. Secondly we present our development in freeform and direct off-axis high performance optical manufacturing capabilities and the industrialization efforts conducted in the frame of the European Extremely Large Telescope (E-ELT) primary mirror segments. A third subject is the demonstration of an extreme freeform surface manufacturing with the prototyping of a huge 500 mm aperture, 90° deviation angle, F/2.5 high output NA Off Axis Parabola (OAP), a unique achievement aimed to confirm the viability of potential new design opportunities involving such type of extreme optics. Finally we present in this paper our technology development on polishing layer for SiC material, named R-SiC, a polishing layer that reduces costs, risks and schedule for advanced SiC optics manufacturing for Vis and IR applications.

  2. Endoscopic probe optics for spectrally encoded confocal microscopy.

    PubMed

    Kang, Dongkyun; Carruth, Robert W; Kim, Minkyu; Schlachter, Simon C; Shishkov, Milen; Woods, Kevin; Tabatabaei, Nima; Wu, Tao; Tearney, Guillermo J

    2013-01-01

    Spectrally encoded confocal microscopy (SECM) is a form of reflectance confocal microscopy that can achieve high imaging speeds using relatively simple probe optics. Previously, the feasibility of conducting large-area SECM imaging of the esophagus in bench top setups has been demonstrated. Challenges remain, however, in translating SECM into a clinically-useable device; the tissue imaging performance should be improved, and the probe size needs to be significantly reduced so that it can fit into luminal organs of interest. In this paper, we report the development of new SECM endoscopic probe optics that addresses these challenges. A custom water-immersion aspheric singlet (NA = 0.5) was developed and used as the objective lens. The water-immersion condition was used to reduce the spherical aberrations and specular reflection from the tissue surface, which enables cellular imaging of the tissue deep below the surface. A custom collimation lens and a small-size grating were used along with the custom aspheric singlet to reduce the probe size. A dual-clad fiber was used to provide both the single- and multi- mode detection modes. The SECM probe optics was made to be 5.85 mm in diameter and 30 mm in length, which is small enough for safe and comfortable endoscopic imaging of the gastrointestinal tract. The lateral resolution was 1.8 and 2.3 µm for the single- and multi- mode detection modes, respectively, and the axial resolution 11 and 17 µm. SECM images of the swine esophageal tissue demonstrated the capability of this device to enable the visualization of characteristic cellular structural features, including basal cell nuclei and papillae, down to the imaging depth of 260 µm. These results suggest that the new SECM endoscopic probe optics will be useful for imaging large areas of the esophagus at the cellular scale in vivo.

  3. Endoscopic probe optics for spectrally encoded confocal microscopy

    PubMed Central

    Kang, DongKyun; Carruth, Robert W.; Kim, Minkyu; Schlachter, Simon C.; Shishkov, Milen; Woods, Kevin; Tabatabaei, Nima; Wu, Tao; Tearney, Guillermo J.

    2013-01-01

    Spectrally encoded confocal microscopy (SECM) is a form of reflectance confocal microscopy that can achieve high imaging speeds using relatively simple probe optics. Previously, the feasibility of conducting large-area SECM imaging of the esophagus in bench top setups has been demonstrated. Challenges remain, however, in translating SECM into a clinically-useable device; the tissue imaging performance should be improved, and the probe size needs to be significantly reduced so that it can fit into luminal organs of interest. In this paper, we report the development of new SECM endoscopic probe optics that addresses these challenges. A custom water-immersion aspheric singlet (NA = 0.5) was developed and used as the objective lens. The water-immersion condition was used to reduce the spherical aberrations and specular reflection from the tissue surface, which enables cellular imaging of the tissue deep below the surface. A custom collimation lens and a small-size grating were used along with the custom aspheric singlet to reduce the probe size. A dual-clad fiber was used to provide both the single- and multi- mode detection modes. The SECM probe optics was made to be 5.85 mm in diameter and 30 mm in length, which is small enough for safe and comfortable endoscopic imaging of the gastrointestinal tract. The lateral resolution was 1.8 and 2.3 µm for the single- and multi- mode detection modes, respectively, and the axial resolution 11 and 17 µm. SECM images of the swine esophageal tissue demonstrated the capability of this device to enable the visualization of characteristic cellular structural features, including basal cell nuclei and papillae, down to the imaging depth of 260 µm. These results suggest that the new SECM endoscopic probe optics will be useful for imaging large areas of the esophagus at the cellular scale in vivo. PMID:24156054

  4. Doppler optical coherence microscopy and tomography applied to inner ear mechanics

    SciTech Connect

    Page, Scott; Freeman, Dennis M.; Ghaffari, Roozbeh

    2015-12-31

    While it is clear that cochlear traveling waves underlie the extraordinary sensitivity, frequency selectivity, and dynamic range of mammalian hearing, the underlying micromechanical mechanisms remain unresolved. Recent advances in low coherence measurement techniques show promise over traditional laser Doppler vibrometry and video microscopy, which are limited by low reflectivities of cochlear structures and restricted optical access. Doppler optical coherence tomography (DOCT) and Doppler optical coherence microscopy (DOCM) both utilize a broadband source to limit constructive interference of scattered light to a small axial depth called a coherence gate. The coherence gate can be swept axially to image and measure sub-nanometer motions of cochlear structures throughout the cochlear partition. The coherence gate of DOCT is generally narrower than the confocal gate of the focusing optics, enabling increased axial resolution (typically 15 μm) within optical sections of the cochlear partition. DOCM, frequently implemented in the time domain, centers the coherence gate on the focal plane, achieving enhanced lateral and axial resolution when the confocal gate is narrower than the coherence gate. We compare these two complementary systems and demonstrate their utility in studying cellular and micromechanical mechanisms involved in mammalian hearing.

  5. Advanced Geothermal Optical Transducer (AGOT)

    SciTech Connect

    2004-09-01

    Today's geothermal pressure-temperature measuring tools are short endurance, high value instruments, used sparingly because their loss is a major expense. In this project LEL offered to build and test a rugged, affordable, downhole sensor capable ofretuming an uninterrupted data stream at pressures and of 10,000 psi and temperatures up to 250 C, thus permitting continuous deep-well logging. It was proposed to meet the need by specializing LEL's patented 'Twin Column Transducer' technology to satisfy the demands of geothermal pressure/temperature measurements. TCT transducers have very few parts, none of which are moving parts, and all of which can be fabricated from high-temperature super alloys or from ceramics; the result is an extremely rugged device, essentially impervious to chemical attack and readily modified to operate at high pressure and temperature. To measure pressure and temperature they capitalize on the relative expansion of optical elements subjected to thermal or mechanical stresses; if one element is maintained at a reference pressure while the other is opened to ambient, the differential displacement then serves as a measure of pressure. A transducer responding to temperature rather than pressure is neatly created by 'inverting' the pressure-measuring design so that both deflecting structures see identical temperatures and temperature gradients, but whose thermal expansion coefficients are deliberately mismatched to give differential expansion. The starting point for development of a PT Tool was the company's model DPT feedback-stabilized 5,000 psi sensor (U.S. Patent 5,311,014, 'Optical Transducer for Measuring Downhole Pressure', claiming a pressure transducer capable of measuring static, dynamic, and true bi-directional differential pressure at high temperatures), shown in the upper portion of Figure 1. The DPT occupies a 1 x 2 x 4-inch volume, weighs 14 ounces, and is accurate to 1 percent of full scale. Employing a pair of identical, low

  6. Fiber-top and ferrule-top cantilevers for atomic force microscopy and scanning near field optical microscopy

    NASA Astrophysics Data System (ADS)

    Chavan, Dhwajal; Gruca, Grzegorz; van de Watering, Tomek; Heeck, Kier; Rector, Jan; Slaman, Martin; Andres, Dieter; Tiribilli, Bruno; Margheri, Giancarlo; Iannuzzi, Davide

    2012-04-01

    Fiber-top and ferrule-top cantilevers (FTC) are a new generation of all optical, monolithic, self-aligned microdevices. They are obtained by carving a cantilever on the cleaved end of an optical fiber (fiber-top) or on a ferrule terminated fiber (ferrule-top). FTCs rely on Fabry-Perot interferometry to measure the deflection of the cantilever with subnanometer deflection sensitivity. FTCs specially developed for scanning probe microscopy are equipped with a sharp tip that has the dual function of probing the topography and collecting/emitting light. We perform the scanning probe microscopy using these probes in air, liquid and at low temperature (12°K). The light emission/collection functionality of FTC probes also allows one to combine scanning near field optical microscopy (SNOM) and optical transmission microscopy with contact and non-contact mode atomic force microscopy (AFM). This makes FTCs ideal for AFM+SNOM on soft samples, polymers and biological specimen, where bent fiber probes and tuning fork based systems would not be recommended because of the high stiffness of those probes. We demonstrate here the capability of fiber-top cantilevers to measure deflection and collect near field optical signal, and also the capability of ferrule-top cantilevers for simultaneous optical transmission microscopy and topography of SNOM gratings. Thanks to their unique features, FTCs also open up possibilities for UV nanolithography and on-demand optical excitation at nanoscale.

  7. A robotized six degree of freedom stage for optical microscopy

    NASA Astrophysics Data System (ADS)

    Avramov, M. Z.; Ivanov, I.; Pavlov, V.; Zaharieva, K.

    2013-04-01

    This work represents an investigation of the possibility to use a hexapod system for optical microscopy investigation and measurements. An appropriate hexapod stage has been developed. The stage has been calibrated and used for several different optical microscopy applications. The construction of the stage is based on the classic Stewart platform and thus represents a parallel robot with 6 degree of freedom. Appropriate software is controlling the transformation of the 3 position coordinates of the moving plate and the 3 Euler angles in position velocities and accelerations of the plate motion. An embedded microcontroller is implementing the motion plan and the PID controller regulating the kinematics. By difference to the available in the market hexapods the proposed solution is with lower precision but is significantly cheaper and simple to maintain. The repeatability obtained with current implementation is 0,05 mm and 0,001 rad. A specialized DSP based video processing engine is used for both feedback computation and application specific image processing in real-time. To verify the concept some applications has been developed for specific tasks and has been used for specific measurements.

  8. Multimodal nonlinear optical microscopy used to discriminate epithelial ovarian cancer

    NASA Astrophysics Data System (ADS)

    Adur, J.; Pelegati, V. B.; de Thomaz, A. A.; Almeida, D. B.; Bottcher-Luiz, F.; Andrade, L. A. L. A.; Cesar, C. L.

    2011-07-01

    We used human specimens of epithelial ovarian cancer (serous type) to test the feasibility of nonlinear imaging as complementary tools for ovarian cancer diagnosis. Classical hematoxylin-and-eosin stained sections were applied to combining two-photon excitation fluorescence (TPEF), second (SHG), and third (THG) harmonic microscopy within the same imaging platform. We show that strong TPEF + SHG + THG signals can be obtained in fixed samples stained with Hematoxylin & Eosin (H&E) stored for a very long time and that H&E staining enhanced the THG signal. We demonstrate using anisotropy and morphological measurements, that SHG and THG of stained optical sections allow reproducible identification of neoplastic features such as architectural alterations of collagen fibrils at different stages of the neoplastic transformation and cellular atypia. Taken together, these results suggest that, with our viable imaging system, we can qualitatively and quantitatively assess endogenous optical biomarkers of the ovarian tissue with SHG and THG microscopy. This imaging capability may prove to be highly valuable in aiding to determine structural changes at the cellular and tissue levels, which may contribute to the development of new diagnostic techniques.

  9. Advances in the atomic force microscopy for critical dimension metrology

    NASA Astrophysics Data System (ADS)

    Hussain, Danish; Ahmad, Khurshid; Song, Jianmin; Xie, Hui

    2017-01-01

    Downscaling, miniaturization and 3D staking of the micro/nano devices are burgeoning phenomena in the semiconductor industry which have posed sophisticated challenges in the critical dimension (CD) metrology. Over the past few years, atomic force microscopy (AFM) has emerged as an important CD metrology technique in meeting these challenges because of its high accuracy, 3D imaging capability, high spatial resolution and non-destructive nature. In this article, advances in the AFM based critical dimension (CD) metrology are systematically reviewed and discussed. CD metrology AFM techniques, strengths, limitations and scanning algorithms are described. Developments towards accurate measurements such as creep and hysteresis compensation of the piezoelectric scanners, their calibration and tip characterization are discussed. In addition, image reconstruction and measures for achieving high accuracy CD measurements with hybrid metrology technique are also discussed. CD metrology challenges offered by the next generation lithography (NGL) techniques such as those associated with the 3D nanodevices of 10 nm node and beyond have been highlighted.

  10. Arc Welders' pneumoconiosis: application of advanced scanning electron microscopy.

    PubMed

    Guidotti, T L; Abraham, J L; DeNee, P B; Smith, J R

    1978-01-01

    Study of lung tissue from necropsy of a 58-year-old arc welder with arc welders' pneumoconiosis, confirmed by history, chest radiography, and pathology, demonstrates the versatility and usefulness of new techniques in scanning electron microscopy (SEM). Secondary electron imaging, the most familiar SEM mode, showed heavy cellular infiltrates in alveoli, the interstitium, and within the interstices of loose whorled fibrotic nodules. Backscattered electron imaging, in which contrast is proportional to elemental atomic number, revealed intracellular metal particles not otherwise visible. Microprobe analysis, energy-dispersive x-ray spectrometry, mapped elemeental iron over the particle image and identified traces of silicon in the whorled nodules. Arc welders' pneumoconiosis appears to be more than a benign siderosis resulting from particulate iron deposition. Simultaneous exposure to other components of welding fumes may alter the pathologic picture, inducing a more complicated fibrotic reaction. The more recently developed advanced techniques of SEM are well suited to the study of pneumoconioses and other problems of heterogenous tissue and mixed chemical systems.

  11. Advanced optics in an interdisciplinary graduate program

    NASA Astrophysics Data System (ADS)

    Nic Chormaic, S.

    2014-07-01

    The Okinawa Institute of Science and Technology Graduate University, established in November 2011, provides a 5- year interdisciplinary PhD program, through English, within Japan. International and Japanese students entering the program undertake coursework and laboratory rotations across a range of topics, including neuroscience, molecular science, physics, chemistry, marine science and mathematics, regardless of previous educational background. To facilitate interdisciplinarity, the university has no departments, ensuring seamless interactions between researchers from all sectors. As part of the PhD program a course in Advanced Optics has been developed to provide PhD students with the practical and theoretical skills to enable them to use optics tools in any research environment. The theoretical aspect of the course introduces students to procedures for complex beam generation (e.g. Laguerre-Gaussian), optical trapping, beam analysis and photon optics, and is supported through a practical program covering introductory interference/diffraction experiments through to more applied fiber optics. It is hoped that, through early exposure to optics handling and measurement techniques, students will be able to develop and utilize optics tools regardless of research field. In addition to the formal course in Advanced Optics, a selection of students also undertakes 13 week laboratory rotations in the Light-Matter Interactions research laboratory, where they work side-by-side with physicists in developing optics tools for laser cooling, photonics or bio-applications. While currently in the first year, conclusive results about the success of such an interdisciplinary PhD training are speculative. However, initial observations indicate a rich cross-fertilization of ideas stemming from the diverse backgrounds of all participants.

  12. Three-dimensional morphological characterization of optic nerve fibers by atomic force microscopy and by scanning electron microscopy.

    PubMed

    Melling, Mahmoud; Karimian-Teherani, Daniela; Mostler, Sascha; Hochmeister, Sonja

    2005-08-01

    A comparative study of scanning electron microscopy (SEM) and atomic force microscopy (AFM) imaging of the healthy human optic nerve was carried out to determine the similarities and the differences. In this study we compared the fine optic nerve structures as observed by SEM and AFM. The fibers of the right optic nerve of a 61-year-old man show different arrangements in transverse sections taken from the same individual 5 mm central to the optic canal and 5 mm peripheral to the optic chiasma; this difference can be recognized by light microscopy (LM), SEM, and AFM. AFM revealed such typical optic nerve fibers (taken from a point 5 mm central to the optic canal) with annular and longitudinal orientations, which were not visible by SEM in this form. By contrast, LM and SEM visualized other structures, such as pia mater and optic nerve fibers loosely arranged in bundles, none of which was visualized by AFM. The images, however, taken 5 mm peripheral from the optic chiasma show shapeless nerve fibers having a wavy course. Our results reveal that more detailed information on optic nerve morphology is obtained by exploiting the advantages of both SEM and AFM. These are the first SEM and AFM images of healthy human optic nerve fibers, containing clear representations of the three dimensions of the optic nerve.

  13. Quantitative photoacoustic microscopy of optical absorption coefficients from acoustic spectra in the optical diffusive regime.

    PubMed

    Guo, Zijian; Favazza, Christopher; Garcia-Uribe, Alejandro; Wang, Lihong V

    2012-06-01

    Photoacoustic (PA) microscopy (PAM) can image optical absorption contrast with ultrasonic spatial resolution in the optical diffusive regime. Conventionally, accurate quantification in PAM requires knowledge of the optical fluence attenuation, acoustic pressure attenuation, and detection bandwidth. We circumvent this requirement by quantifying the optical absorption coefficients from the acoustic spectra of PA signals acquired at multiple optical wavelengths. With the acoustic spectral method, the absorption coefficients of an oxygenated bovine blood phantom at 560, 565, 570, and 575 nm were quantified with errors of <3%. We also quantified the total hemoglobin concentration and hemoglobin oxygen saturation in a live mouse. Compared with the conventional amplitude method, the acoustic spectral method provides greater quantification accuracy in the optical diffusive regime. The limitations of the acoustic spectral method was also discussed.

  14. Visualizing enantioselective optical forces with chiral force microscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Saleh, Amr; van de Haar, Marie-Anne; Polman, Albert; Dionne, Jennifer A.

    2016-09-01

    Enantiomer separation is a critical step in many chemical syntheses, particularly for pharmaceuticals, but prevailing chemical methods remain inefficient. Here, we introduce an optical technique to sort chiral specimens using coaxial plasmonic apertures. These apertures are composed of a deeply subwavelength dielectric channel embedded in silver (or gold) and can stably trap sub-20-nm dielectric specimens. Using both full-field simulations and analytic calculations, we first show that selective trapping of enantiomers can be achieved with circularly polarized illumination and proper index-matching of the immersed liquid with the particles being trapped. Opposite enantiomers experience distinct trapping forces in both sign and magnitude: one is trapped in a deep potential well while the other is repelled with a potential barrier. These potentials maintain opposite signs across a range of chiral polarizabilities and enantiomer-aperture separations. We also demonstrate how atomic force microscopy can be used to directly probe the near field optical forces from our coaxial nano-aperture. Our measurement reveals the spatial distribution of the optical near-field forces on a nanometer-sized dielectric specimen. To directly visualize the enantio-selective optical forces, we pattern silicon AFM-probes with chiral patterns. Our near-field force mapping indicates a differentiable force in the piconewton range on the chiral probes, exerted by our coaxial aperture with circularly polarized illumination. Our theoretical and experimental demonstrations indicate that the interaction of chiral light and chiral specimens can be mediated by achiral plasmonic apertures, providing a possible route toward all-optical enantiopure syntheses.

  15. Using advanced electron microscopy for the characterization of catalytic materials

    NASA Astrophysics Data System (ADS)

    Pyrz, William D.

    Catalysis will continue to be vitally important to the advancement and sustainability of industrialized societies. Unfortunately, the petroleum-based resources that currently fuel the energy and consumer product needs of an advancing society are becoming increasingly difficult and expensive to extract as supplies diminish and the quality of sources degrade. Therefore, the development of sustainable energy sources and the improvement of the carbon efficiency of existing chemical processes are critical. Further challenges require that these initiatives are accomplished in an environmentally friendly fashion since the effects of carbon-based emissions are proving to be a serious threat to global climate stability. In this dissertation, materials being developed for sustainable energy and process improvement initiatives are studied. Our approach is to use materials characterization, namely advanced electron microscopy, to analyze the targeted systems at the nano- or Angstrom-scale with the goal of developing useful relationships between structure, composition, crystalline order, morphology, and catalytic performance. One area of interest is the complex Mo-V-M-O (M=Te, Sb, Ta, Nb) oxide system currently being developed for the selective oxidation/ammoxidation of propane to acrylic acid or acrylonitrile, respectively. Currently, the production of acrylic acid and acrylonitrile rely on propylene-based processes, yet significant cost savings could be realized if the olefin-based feeds could be replaced by paraffin-based ones. The major challenge preventing this feedstock replacement is the development of a suitable paraffin-activating catalyst. Currently, the best candidate is the Mo-V-Nb-Te-O complex oxide catalyst that is composed of two majority phases that are commonly referred to as M1 and M2. However, there is a limited understanding of the roles of each component with respect to how they contribute to catalyst stability and the reaction mechanism. Aberration

  16. Advanced high-bandwidth optical fuzing technology

    NASA Astrophysics Data System (ADS)

    Liu, Jony J.; von der Lippe, Christian M.

    2005-10-01

    A robust and compact photonic proximity sensor is developed for optical fuze in munitions applications. The design of the optical fuze employed advanced optoelectronic technologies including high-power vertical-cavity surface-emitting lasers (VCSELs), the p-i-n or metal-semiconductor-metal (MSM) photodetectors, SiGe ASIC driver, and miniature optics. The development combines pioneering work and unique expertise at ARDEC, ARL, and Sandia National Laboratories and synergizes the key optoelectronic technologies in components and system designs. This compact sensor will replace conventional costly assemblies based on discrete lasers, photodetectors, and bulky optics and provide a new capability for direct fire applications. It will be mass manufacturable in low cost and simplicity. In addition to the specific applications for gun-fired munitions, numerous civilian uses can be realized by this proximity sensor in automotive, robotics, and aerospace applications. This technology is also applicable to robotic ladar and short-range 3-D imaging.

  17. Hyperspectral Dark Field Optical Microscopy of Single Silver Nanospheres

    SciTech Connect

    El-Khoury, Patrick Z.; Joly, Alan G.; Hess, Wayne P.

    2016-04-07

    We record spectrally (400 nm ≤ λ ≤ 675 nm, Δλ < 4.69 nm) and spatially (diffraction-limited, sampled at 85 nm2/pixel) resolved dark field (DF) scattering from single silver nanospheres of 100 nm in diameter. Hyperspectral DF optical microscopy is achieved by coupling a hyperspectral detector to an optical microscope, whereby spectrally resolved diffraction-limited images of hundreds of silver nanoparticles can be recorded in ~30 seconds. We demonstrate how the centers and edges of individual particles can be localized in 2D to within a single pixel (85 nm2), using a statistical method for examining texture based on a co-occurrence matrix. Subsequently, spatial averaging of the spectral response in a 3x3 pixel area around the particle centers affords ample signal-to-noise to resolve the plasmon resonance of a single silver nanosphere. A close inspection of the scattering spectra of 31 different nanospheres reveals that each particle has its unique (i) relative scattering efficiency, and (ii) plasmon resonance maximum and dephasing time. These observations are suggestive of nanometric structural variations over length scales much finer than the spatial resolution attainable using the all-optical technique described herein.

  18. Automated control of optical polarization for nonlinear microscopy

    NASA Astrophysics Data System (ADS)

    Brideau, Craig; Stys, Peter K.

    2012-03-01

    Laser-scanning non-linear optical techniques such as multi-photon fluorescence excitation microscopy (MPM), Second/ Third Harmonic Generation (SHG/THG), and Coherent Anti-Stokes Raman Scattering (CARS) are being utilized in research laboratories worldwide. The efficiencies of these non-linear effects are dependent on the polarization state of the excitation light relative to the orientation of the sample being imaged. In highly ordered anisotropic biological samples this effect can become pronounced and the excitation polarization can have a dramatic impact on imaging experiments. Therefore, controlling the polarization state of the exciting light is important; however this is challenging when the excitation light passes through a complex optical system. In a typical laser-scanning microscope, components such as the dichroic filters, lenses, and even mirrors can alter the polarization state of a laser beam before it reaches the sample. We present an opto-mechanical solution to compensate for the polarization effects of an optical path, and to precisely program the polarization state of the exciting laser light. The device and accompanying procedures allow the delivery of precise laser polarization states at constant average power levels to a sample during an imaging experiment.

  19. Design of a handheld optical coherence microscopy endoscope

    NASA Astrophysics Data System (ADS)

    Korde, Vrushali R.; Liebmann, Erica; Barton, Jennifer K.

    2009-02-01

    Optical Coherence Microscopy (OCM) combines coherence gating, high numerical aperture optics, and a fiber core pinhole to provide high axial and lateral resolution with relatively large depth of imaging. We present a handheld rigid OCM endoscope with a 6 mm diameter tip, 1 mm scan width, and 1 mm imaging depth. This probe will allow noninvasive imaging of fine structural detail in vivo. X-Y scanning is performed distally with mirrors mounted to micro galvonometer scanners incorporated into the endoscope handle. Two scanning doublet lenses relay the stop from the galvonometers to the afocal relay stop. The endoscope optical design consists of an afocal Hopkins relay lens system and a 0.4 NA objective. To allow focusing at various depths in the tissue, the endoscope housing is designed in two pieces screwed together with a fine pitch threads. A small rotation of the outer housing moves the lenses proximal and distal relative to the window, causing the focal location in the tissue to change. The space between the final objective lens and the window is filled with distilled water to avoid misalignment of the focus and coherence gate. A knife edge test was performed and the line spread function FWHM was measured to be 2.25 μm. The MTF has at least 0.3 contrast at a 5 μm line pair. This rigid handheld OCM endoscope will be useful for application ranging from minimally invasive surgical imaging to assessing dysplasia and sun damage in skin.

  20. Modeling of optical quadrature microscopy for imaging mouse embryos

    NASA Astrophysics Data System (ADS)

    Warger, William C., II; DiMarzio, Charles A.

    2008-02-01

    Optical quadrature microscopy (OQM) has been shown to provide the optical path difference through a mouse embryo, and has led to a novel method to count the total number of cells further into development than current non-toxic imaging techniques used in the clinic. The cell counting method has the potential to provide an additional quantitative viability marker for blastocyst transfer during in vitro fertilization. OQM uses a 633 nm laser within a modified Mach-Zehnder interferometer configuration to measure the amplitude and phase of the signal beam that travels through the embryo. Four cameras preceded by multiple beamsplitters record the four interferograms that are used within a reconstruction algorithm to produce an image of the complex electric field amplitude. Here we present a model for the electric field through the primary optical components in the imaging configuration and the reconstruction algorithm to calculate the signal to noise ratio when imaging mouse embryos. The model includes magnitude and phase errors in the individual reference and sample paths, fixed pattern noise, and noise within the laser and detectors. This analysis provides the foundation for determining the imaging limitations of OQM and the basis to optimize the cell counting method in order to introduce additional quantitative viability markers.

  1. Near-field scanning optical microscopy investigations of conjugated polymers

    NASA Astrophysics Data System (ADS)

    Dearo, Jessie Ann

    The Near-Field Scanning Optical Microscopy (NSOM) studies of novel, optically active, conjugated polymers are presented. NSOM is a relatively new technique which produces super resolution (˜50--100 nm) optical images simultaneously with topography. The conjugated polymer poly(p-phenylene vinylene) (PPV) and derivatives of PPV are organic semiconductor-like materials with interesting and unique optical properties. Derivatives of PPV have been used in LEDs and have potential in other optoelectronic devices. NSOM provides a tool for investigation of the photoluminescence, absorption/reflection, photo-dynamics and photoconductivity of films of PPV and PPV derivatives on the length scale that these properties are fundamentally defined. The NSOM experiments have revealed mesoscale domains (˜100 nm) of varying photoluminescence emission and average molecular order in drop cast films of PPV. NSOM of stretch-oriented PPV have shown domains of perpendicular molecular orientation with low photoluminescence emission. Near-field photoconductivity experiments of stretch-oriented PPV have correlated the mesoscale topography with the photoconductivity properties of the polymer. NSOM experiments of films of poly(2-methoxy, 5-(2'-(ethyl(hexyloxy)-p-phenylene vinylene) (MEH-PPV) have shown that there is mesoscale spatial inhomogeneity in the photo-oxidation process which reduces photoluminescence emission. NSOM has also been used to create nanoscale photo-patterning in MEH-PPV films. The NSOM experiments of blended films of MEH-PPV in polystyrene have shown mesoscale phase separation directly correlated to variations in the optical properties of the film. Derivatives of PPV, stretch-oriented in polyethylene, show photoluminescence intensity variations perpendicular and parallel to the stretch-direction correlated to topography features. As a complement to the NSOM studies of conjugated polymers, single polymer molecule experiments of MEH-PPV are also presented. The

  2. Multifocus microscopy with precise color multi-phase diffractive optics applied in functional neuronal imaging

    PubMed Central

    Abrahamsson, Sara; Ilic, Rob; Wisniewski, Jan; Mehl, Brian; Yu, Liya; Chen, Lei; Davanco, Marcelo; Oudjedi, Laura; Fiche, Jean-Bernard; Hajj, Bassam; Jin, Xin; Pulupa, Joan; Cho, Christine; Mir, Mustafa; El Beheiry, Mohamed; Darzacq, Xavier; Nollmann, Marcelo; Dahan, Maxime; Wu, Carl; Lionnet, Timothée; Liddle, J. Alexander; Bargmann, Cornelia I.

    2016-01-01

    Multifocus microscopy (MFM) allows high-resolution instantaneous three-dimensional (3D) imaging and has been applied to study biological specimens ranging from single molecules inside cells nuclei to entire embryos. We here describe pattern designs and nanofabrication methods for diffractive optics that optimize the light-efficiency of the central optical component of MFM: the diffractive multifocus grating (MFG). We also implement a “precise color” MFM layout with MFGs tailored to individual fluorophores in separate optical arms. The reported advancements enable faster and brighter volumetric time-lapse imaging of biological samples. In live microscopy applications, photon budget is a critical parameter and light-efficiency must be optimized to obtain the fastest possible frame rate while minimizing photodamage. We provide comprehensive descriptions and code for designing diffractive optical devices, and a detailed methods description for nanofabrication of devices. Theoretical efficiencies of reported designs is ≈90% and we have obtained efficiencies of > 80% in MFGs of our own manufacture. We demonstrate the performance of a multi-phase MFG in 3D functional neuronal imaging in living C. elegans. PMID:27231594

  3. Advanced optical blade tip clearance measurement system

    NASA Technical Reports Server (NTRS)

    Ford, M. J.; Honeycutt, R. E.; Nordlund, R. E.; Robinson, W. W.

    1978-01-01

    An advanced electro-optical system was developed to measure single blade tip clearances and average blade tip clearances between a rotor and its gas path seal in an operating gas turbine engine. This system is applicable to fan, compressor, and turbine blade tip clearance measurement requirements, and the system probe is particularly suitable for operation in the extreme turbine environment. A study of optical properties of blade tips was conducted to establish measurement system application limitations. A series of laboratory tests was conducted to determine the measurement system's operational performance characteristics and to demonstrate system capability under simulated operating gas turbine environmental conditions. Operational and environmental performance test data are presented.

  4. Advanced optics experiments using nonuniform aperture functions

    NASA Astrophysics Data System (ADS)

    Wood, Lowell T.

    2013-05-01

    A method to create instructive, nonuniform aperture functions using spatial frequency filtering is described. The diffraction from a single slit in the Fresnel limit and the interference from a double slit in the Fraunhofer limit are spatially filtered to create electric field distributions across an aperture to produce apodization, inverse apodization or super-resolution, and apertures with phase shifts across their widths. The diffraction effects from these aperture functions are measured and calculated. The excellent agreement between the experimental results and the calculated results makes the experiment ideal for use in an advanced undergraduate or graduate optics laboratory to illustrate experimentally several effects in Fourier optics.

  5. Advanced Optical A/D Converter

    DTIC Science & Technology

    1993-05-01

    before the receiver and separately by reducing the gain in the EDFA . It is important to note that the optical power level was varied while all the...could not exceed roughly 50% of the maximum power available at full gain from the EDFA . 4.2 Baseband-Mode Testing The single-channel system was also...AD-A275 663 Advanced Optical A/D Convert M.C. Hamilton, J.A. Bell, D.A. Leep, J.P. Lin The Boeing Company Boeing Defense and Space Group P.O. Box

  6. Optical-resolution photoacoustic microscopy of ischemic stroke

    NASA Astrophysics Data System (ADS)

    Hu, Song; Gonzales, Ernie; Soetikno, Brian; Gong, Enhao; Yan, Ping; Maslov, Konstantin; Lee, Jin-Moo; Wang, Lihong V.

    2011-03-01

    A major obstacle in understanding the mechanism of ischemic stroke is the lack of a tool to noninvasively or minimally invasively monitor cerebral hemodynamics longitudinally. Here, we applied optical-resolution photoacoustic microscopy (OR-PAM) to longitudinally study ischemic stroke induced brain injury in a mouse model with transient middle cerebral artery occlusion (MCAO). OR-PAM showed that, during MCAO, the average hemoglobin oxygen saturation (sO2) values of feeder arteries and draining veins within the stroke core region dropped ~10% and ~34%, respectively. After reperfusion, arterial sO2 recovered back to the baseline; however, the venous sO2 increased above the baseline value by ~7%. Thereafter, venous sO2 values were close to the arterial sO2 values, suggesting eventual brain tissue infarction.

  7. Adaptive optics for confocal laser scanning microscopy with adjustable pinhole

    NASA Astrophysics Data System (ADS)

    Yoo, Han Woong; van Royen, Martin E.; van Cappellen, Wiggert A.; Houtsmuller, Adriaan B.; Verhaegen, Michel; Schitter, Georg

    2016-04-01

    The pinhole plays an important role in confocal laser scanning microscopy (CLSM) for adaptive optics (AO) as well as in imaging, where the size of the pinhole denotes a trade-off between out-of-focus rejection and wavefront distortion. This contribution proposes an AO system for a commercial CLSM with an adjustable square pinhole to cope with such a trade-off. The proposed adjustable pinhole enables to calibrate the AO system and to evaluate the imaging performance. Experimental results with fluorescence beads on the coverslip and at a depth of 40 μm in the human hepatocellular carcinoma cell spheroid demonstrate that the proposed AO system can improve the image quality by the proposed calibration method. The proposed pinhole intensity ratio also indicates the image improvement by the AO correction in intensity as well as resolution.

  8. Wavefront sensorless adaptive optics temporal focusing-based multiphoton microscopy.

    PubMed

    Chang, Chia-Yuan; Cheng, Li-Chung; Su, Hung-Wei; Hu, Yvonne Yuling; Cho, Keng-Chi; Yen, Wei-Chung; Xu, Chris; Dong, Chen Yuan; Chen, Shean-Jen

    2014-06-01

    Temporal profile distortions reduce excitation efficiency and image quality in temporal focusing-based multiphoton microscopy. In order to compensate the distortions, a wavefront sensorless adaptive optics system (AOS) was integrated into the microscope. The feedback control signal of the AOS was acquired from local image intensity maximization via a hill-climbing algorithm. The control signal was then utilized to drive a deformable mirror in such a way as to eliminate the distortions. With the AOS correction, not only is the axial excitation symmetrically refocused, but the axial resolution with full two-photon excited fluorescence (TPEF) intensity is also maintained. Hence, the contrast of the TPEF image of a R6G-doped PMMA thin film is enhanced along with a 3.7-fold increase in intensity. Furthermore, the TPEF image quality of 1μm fluorescent beads sealed in agarose gel at different depths is improved.

  9. Linear and Nonlinear Optical Spectroscopy at the Nanoscale with Photoinduced Force Microscopy.

    PubMed

    Jahng, Junghoon; Fishman, Dmitry A; Park, Sung; Nowak, Derek B; Morrison, Will A; Wickramasinghe, H Kumar; Potma, Eric O

    2015-10-20

    The enormous advances made in nanotechnology have also intensified the need for tools that can characterize newly synthesized nanoaterials with high sensitivity and with high spatial resolution. Many existing tools with nanoscopic resolution or better, including scanning electron microscopy (SEM), atomic force microscopy (AFM), and scanning tunneling microscopy (STM) methods, can generate highly detailed maps of nanoscopic structures. However, while these approaches provide great views of the morphological properties of nanomaterials, it has proven more challenging to derive chemical information from the corresponding images. To address this issue, attempts have been made to dress existing nanoscopy methods with spectroscopic sensitivity. A powerful approach in this direction is the combination of scan probe techniques with optical illumination, which aims to marry the nanoscopic resolution provided by a sharp tip with the chemical selectivity provided by optical spectroscopy. Examples of this approach include existing techniques such as scattering-type scanning near-field optical microscopy and tip-enhanced Raman spectroscopy. A new and emerging technique in this direction is photoinduced force microscopy (PiFM), which enables spectroscopic probing of materials with a spatial resolution well under 10 nm. In PiFM, the sample is optically excited and the response of the material is probed directly in the near-field by reading out the time-integrated force between the tip and the sample. Because the magnitude of the force is dependent on the photoinduced polarization in the sample, PiFM exhibits spectroscopic sensitivity. The photoinduced forces measured in PiFM are spatially confined on the nanometer scale, which translates into a very high spatial resolution even under ambient conditions. The PiFM approach is compatible with a wide range optical excitation frequencies, from the visible to the mid-infrared, enabling nanoscale imaging contrast based on either

  10. Advances in small animal mesentery models for in vivo flow cytometry, dynamic microscopy, and drug screening

    PubMed Central

    Galanzha, Ekaterina I; Tuchin, Valery V; Zharov, Vladimir P

    2007-01-01

    Using animal mesentery with intravital optical microscopy is a well-established experimental model for studying blood and lymph microcirculation in vivo. Recent advances in cell biology and optical techniques provide the basis for extending this model for new applications, which should generate significantly improved experimental data. This review summarizes the achievements in this specific area, including in vivo label-free blood and lymph photothermal flow cytometry, super-sensitive fluorescence image cytometry, light scattering and speckle flow cytometry, microvessel dynamic microscopy, infrared (IR) angiography, and high-speed imaging of individual cells in fast flow. The capabilities of these techniques, using the rat mesentery model, were demonstrated in various studies; e.g., real-time quantitative detection of circulating and migrating individual blood and cancer cells, studies on vascular dynamics with a focus on lymphatics under normal conditions and under different interventions (e.g. lasers, drugs, nicotine), assessment of lymphatic disturbances from experimental lymphedema, monitoring cell traffic between blood and lymph systems, and high-speed imaging of cell transient deformability in flow. In particular, the obtained results demonstrated that individual cell transportation in living organisms depends on cell type (e.g., normal blood or leukemic cells), the cell’s functional state (e.g., live, apoptotic, or necrotic), and the functional status of the organism. Possible future applications, including in vivo early diagnosis and prevention of disease, monitoring immune response and apoptosis, chemo- and radio-sensitivity tests, and drug screening, are also discussed. PMID:17226898

  11. Optical pump-probe microscopy for biomedicine and art conservation

    NASA Astrophysics Data System (ADS)

    Fischer, Martin

    2013-03-01

    Nonlinear optical microscopy can provide contrast in highly heterogeneous media and a wide range of applications has emerged, primarily in biology, medicine, and materials science. Compared to linear microscopy methods, the localized nature of nonlinear interactions leads to high spatial resolution, optical sectioning, and larger possible imaging depth in scattering media. However, nonlinear contrast (other than fluorescence, harmonic generation or CARS) is generally difficult to measure because it is overwhelmed by the large background of detected illumination light. This background can be suppressed by using femtosecond pulse or pulse train shaping to encode nonlinear interactions in background-free regions of the frequency spectrum. We have developed this shaping technology to study novel intrinsic structural and molecular contrast in biological tissue, generally using less power than a laser pointer. For example we have recently been able to sensitively measure detailed transient absorption dynamics of melanin sub-types in a variety of skin lesions, showing clinically relevant differences of melanin type and distribution between cancerous and benign tissue.[1] Recently we have also applied this technology to paint samples and to historic artwork in order to provide detailed, depth-resolved pigment identification. Initial studies in different inorganic and organic pigments have shown a rich and pigment-specific nonlinear absorption signature.[2] Some pigments, for example lapis lazuli (natural ultramarine), even show marked differences in signal depending on its geographic origin and on age, demonstrating the potential of this technique to determine authenticity, provenance, technology of manufacture, or state of preservation of historic works of art.

  12. Multimodal nonlinear optical microscopy used to discriminate human colon cancer

    NASA Astrophysics Data System (ADS)

    Adur, Javier; Pelegati, Vitor B.; Bianchi, Mariana; de Thomaz, André A.; Baratti, Mariana O.; Carvalho, Hernandes F.; Casco, Víctor H.; Cesar, Carlos L.

    2013-02-01

    Colon cancer is one of the most diffused cancers in the Western World, ranking third worldwide in frequency of incidence after lung and breast cancers. Even if it is curable when detected and treated early, a more accurate premature diagnosis would be a suitable aim for both cancer prognostic and treatment. Combined multimodal nonlinear optical (NLO) microscopies, such as two-photon excitation fluorescence (TPEF), second-harmonic generation (SHG), third harmonic generation (THG), and fluorescence lifetime imaging microscopy (FLIM) can be used to detect morphological and metabolic changes associated with stroma and epithelial transformation in colon cancer disease. NLO microscopes provide complementary information about tissue microstructure, showing distinctive patterns between normal and malignant human colonic mucosa. Using a set of scoring methods significant differences both in the content, distribution and organization of stroma collagen fibrils, and lifetime components of NADH and FAD cofactors of human colon mucosa biopsies were found. Our results provide a framework for using NLO techniques as a clinical diagnostic tool for human colon cancer, and also suggest that the SHG and FLIM metrics could be applied to other intestinal disorders, which are characterized by abnormal cell proliferation and collagen assembly.

  13. Extended focus Fourier domain optical coherence microscopy assists developmental biology

    NASA Astrophysics Data System (ADS)

    Villiger, Martin L.; Beleut, Manfred; Brisken, Cathrin; Lasser, Theo; Leitgeb, Rainer A.

    2007-07-01

    We present a novel detection scheme for Fourier domain optical coherence microscopy (FDOCM). A Bessel-like interference pattern with a strong central lobe was created with an axicon lens. This pattern was then imaged by a telescopic system into the sample space to obtain a laterally highly confined illumination needle, extending over a long axial range. For increased efficiency, the detection occurs decoupled from the illumination, avoiding a double pass through the axicon. Nearly constant transverse resolution of ~1.5μm along a focal range of 200μm with a maximum sensitivity of 105dB was obtained. A broad bandwidth Ti:Sapphire laser allowed for an axial resolution of 3μm in air, providing the nearly isotropic resolution necessary to access the microstructure of biological tissues. Together with the speed- and sensitivity-advantage of FDOCT, this system can perform in vivo measurements in a minimally invasive way. Tomograms of the mouse mammary gland and the mouse follicle, recorded in vitro, revealed biologically relevant structural details. Images acquired with classical microscopy techniques, involving stained and fluorescent samples, validate these structures and emphasize the high contrast of the tomograms. It is comparable to the contrast achieved with classical techniques, but employing neither staining, labeling nor slicing of the samples, stressing the high potential of FDOCM for minimally invasive in vivo small animal imaging.

  14. Soliton molecules for advanced optical telecommunications

    NASA Astrophysics Data System (ADS)

    Mitschke, Fedor; Hause, Alexander; Mahnke, Christoph

    2016-11-01

    Recent developments in the technology of optical telecommunications are pushed forward by the rapidly growing demand for data-carrying capacity. Current approaches are discussed; most lines of investigation are limited to the linear (i.e. low power) regime. It is shown how this restriction poses a limit for further evolution. If, on the other hand, the nonlinear regime is entered, recent developments about soliton molecules offer a possibility to advance further.

  15. Non-iterative adaptive optical microscopy using wavefront sensing

    NASA Astrophysics Data System (ADS)

    Tao, X.; Azucena, O.; Kubby, J.

    2016-03-01

    This paper will review the development of wide-field and confocal microscopes with wavefront sensing and adaptive optics for correcting refractive aberrations and compensating scattering when imaging through thick tissues (Drosophila embryos and mouse brain tissue). To make wavefront measurements in biological specimens we have modified the laser guide-star techniques used in astronomy for measuring wavefront aberrations that occur as star light passes through Earth's turbulent atmosphere. Here sodium atoms in Earth's mesosphere, at an altitude of 95 km, are excited to fluoresce at resonance by a high-power sodium laser. The fluorescent light creates a guide-star reference beacon at the top of the atmosphere that can be used for measuring wavefront aberrations that occur as the light passes through the atmosphere. We have developed a related approach for making wavefront measurements in biological specimens using cellular structures labeled with fluorescent proteins as laser guide-stars. An example is a fluorescently labeled centrosome in a fruit fly embryo or neurons and dendrites in mouse brains. Using adaptive optical microscopy we show that the Strehl ratio, the ratio of the peak intensity of an aberrated point source relative to the diffraction limited image, can be improved by an order of magnitude when imaging deeply into live dynamic specimens, enabling near diffraction limited deep tissue imaging.

  16. Full-color structured illumination optical sectioning microscopy

    PubMed Central

    Qian, Jia; Lei, Ming; Dan, Dan; Yao, Baoli; Zhou, Xing; Yang, Yanlong; Yan, Shaohui; Min, Junwei; Yu, Xianghua

    2015-01-01

    In merits of super-resolved resolution and fast speed of three-dimensional (3D) optical sectioning capability, structured illumination microscopy (SIM) has found variety of applications in biomedical imaging. So far, most SIM systems use monochrome CCD or CMOS cameras to acquire images and discard the natural color information of the specimens. Although multicolor integration scheme are employed, multiple excitation sources and detectors are required and the spectral information is limited to a few of wavelengths. Here, we report a new method for full-color SIM with a color digital camera. A data processing algorithm based on HSV (Hue, Saturation, and Value) color space is proposed, in which the recorded color raw images are processed in the Hue, Saturation, Value color channels, and then reconstructed to a 3D image with full color. We demonstrated some 3D optical sectioning results on samples such as mixed pollen grains, insects, micro-chips and the surface of coins. The presented technique is applicable to some circumstance where color information plays crucial roles, such as in materials science and surface morphology. PMID:26415516

  17. Optical Sizing of Immunolabel Clusters through Multispectral Plasmon Coupling Microscopy

    PubMed Central

    Wang, Hongyun; Rong, Guoxin; Yan, Bo; Yang, Linglu; Reinhard, Björn M.

    2011-01-01

    The wavelength dependent scattering cross-sections of self-assembled silver nanoparticle clusters of known size (n) were measured on five different wavelength channels between 427 and 510 nm through correlation of multispectral imaging and scanning electron microscopy. A multivariate statistical analysis of the spectral response of this training set provided a correlation between spectral response and cluster size and enabled a classification of new measurements into four distinct nanoparticle association levels (I1 – I4) whose compositions were dominated by monomers (I1), dimers (I2), trimers and tetramers (I3), and larger clusters (I4), respectively. One potential application of the optical sizing approach is to map association levels of silver immunolabels on cellular surfaces. We demonstrate the feasibility of this approach using silver immunolabels targeted at the epidermal growth factor receptor on A431 cells in a proof of principle experiment. The ability to measure immunolabel association levels on sub-cellular length scales in an optical microscope provides new opportunities for experimentally assessing receptor density distributions on living cells in solution. PMID:21247191

  18. Full-color structured illumination optical sectioning microscopy

    NASA Astrophysics Data System (ADS)

    Qian, Jia; Lei, Ming; Dan, Dan; Yao, Baoli; Zhou, Xing; Yang, Yanlong; Yan, Shaohui; Min, Junwei; Yu, Xianghua

    2015-09-01

    In merits of super-resolved resolution and fast speed of three-dimensional (3D) optical sectioning capability, structured illumination microscopy (SIM) has found variety of applications in biomedical imaging. So far, most SIM systems use monochrome CCD or CMOS cameras to acquire images and discard the natural color information of the specimens. Although multicolor integration scheme are employed, multiple excitation sources and detectors are required and the spectral information is limited to a few of wavelengths. Here, we report a new method for full-color SIM with a color digital camera. A data processing algorithm based on HSV (Hue, Saturation, and Value) color space is proposed, in which the recorded color raw images are processed in the Hue, Saturation, Value color channels, and then reconstructed to a 3D image with full color. We demonstrated some 3D optical sectioning results on samples such as mixed pollen grains, insects, micro-chips and the surface of coins. The presented technique is applicable to some circumstance where color information plays crucial roles, such as in materials science and surface morphology.

  19. DVD pickup head based optical resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Po-Hsun; Li, Meng-Lin

    2012-02-01

    Optical resolution photoacoustic microscopy (OR-PAM) has been shown as a promising tool for label-free microvascular and single-cell imaging in clinical and bioscientific applications. However, most OR-PAM systems are realized by using a bulky laser for photoacoustic excitation. The large volume and high price of the laser may restrain the popularity of OR-PAM. In this study, we develop a low-cost and compact OR-PAM system based on a commercially available DVD pickup head. We showed that the DVD pickup head have the required laser energy and focusing optics for OR-PAM. The firmware of a DVD burner was modified to enable its laser diode to provide a 13-ns laser pulse with 1.3-nJ energy at 650 nm. Two excitation wavelengths at 650 and 780 nm were available. The laser beam was focused onto the target after passing through a 0.6-mm thick DVD transparent polycarbonate coating, and then aligned to be confocal with a 50-MHz focused ultrasonic transducer in forward mode. To keep the target on focus, a scan involving auto-tracking procedure was performed. The lateral resolution was verified via cross-sectional imaging of a 6-μm carbon fiber. The measured -6 dB width of the carbon fiber was 6.66 μm which was in agreement with optical diffraction limit. The proposed OR-PAM has potential as an economically viable and compact blood screening tool available outside of large laboratories due to its low cost and portability. Furthermore, a better spatial resolution could be provided by using a blue ray DVD pickup head.

  20. Combined optical and mechanical scanning in optical-resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Li, Lei; Yeh, Chenghung; Hu, Song; Wang, Lidai; Soetikno, Brian T.; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk; Maslov, Konstantin I.; Wang, Lihong V.

    2014-03-01

    Combined optical and mechanical scanning (COMS) in optical-resolution photoacoustic microscopy (OR-PAM) has provided five scanning modes with fast imaging speed and wide field of view (FOV). With two-dimensional (2D) galvanometer-based optical scanning, we have achieved a 2 KHz B-scan rate and 50 Hz volumetric-scan rate, which enables real-time tracking of cell activities in vivo. With optical-mechanical hybrid 2D scanning, we are able to image a wide FOV (10×8 mm2) within 150 seconds, which is 20 times faster than the conventional mechanical scan in our second-generation OR-PAM. With three-dimensional mechanical-based contour scanning, we can maintain the optimal signal-to-noise ratio and spatial resolution of OR-PAM while imaging objects with uneven surfaces, which is ideal for fast and quantitative studies of tumors and the brain.

  1. Backscattered Electron Microscopy as an Advanced Technique in Petrography.

    ERIC Educational Resources Information Center

    Krinsley, David Henry; Manley, Curtis Robert

    1989-01-01

    Three uses of this method with sandstone, desert varnish, and granite weathering are described. Background information on this technique is provided. Advantages of this type of microscopy are stressed. (CW)

  2. Differential Polarization Nonlinear Optical Microscopy with Adaptive Optics Controlled Multiplexed Beams

    PubMed Central

    Samim, Masood; Sandkuijl, Daaf; Tretyakov, Ian; Cisek, Richard; Barzda, Virginijus

    2013-01-01

    Differential polarization nonlinear optical microscopy has the potential to become an indispensable tool for structural investigations of ordered biological assemblies and microcrystalline aggregates. Their microscopic organization can be probed through fast and sensitive measurements of nonlinear optical signal anisotropy, which can be achieved with microscopic spatial resolution by using time-multiplexed pulsed laser beams with perpendicular polarization orientations and photon-counting detection electronics for signal demultiplexing. In addition, deformable membrane mirrors can be used to correct for optical aberrations in the microscope and simultaneously optimize beam overlap using a genetic algorithm. The beam overlap can be achieved with better accuracy than diffraction limited point-spread function, which allows to perform polarization-resolved measurements on the pixel-by-pixel basis. We describe a newly developed differential polarization microscope and present applications of the differential microscopy technique for structural studies of collagen and cellulose. Both, second harmonic generation, and fluorescence-detected nonlinear absorption anisotropy are used in these investigations. It is shown that the orientation and structural properties of the fibers in biological tissue can be deduced and that the orientation of fluorescent molecules (Congo Red), which label the fibers, can be determined. Differential polarization microscopy sidesteps common issues such as photobleaching and sample movement. Due to tens of megahertz alternating polarization of excitation pulses fast data acquisition can be conveniently applied to measure changes in the nonlinear signal anisotropy in dynamically changing in vivo structures. PMID:24022688

  3. Nonlinear optical microscopy reveals invading endothelial cells anisotropically alter three-dimensional collagen matrices

    SciTech Connect

    Lee, P.-F.; Yeh, Alvin T.; Bayless, Kayla J.

    2009-02-01

    The interactions between endothelial cells (ECs) and the extracellular matrix (ECM) are fundamental in mediating various steps of angiogenesis, including cell adhesion, migration and sprout formation. Here, we used a noninvasive and non-destructive nonlinear optical microscopy (NLOM) technique to optically image endothelial sprouting morphogenesis in three-dimensional (3D) collagen matrices. We simultaneously captured signals from collagen fibers and endothelial cells using second harmonic generation (SHG) and two-photon excited fluorescence (TPF), respectively. Dynamic 3D imaging revealed EC interactions with collagen fibers along with quantifiable alterations in collagen matrix density elicited by EC movement through and morphogenesis within the matrix. Specifically, we observed increased collagen density in the area between bifurcation points of sprouting structures and anisotropic increases in collagen density around the perimeter of lumenal structures, but not advancing sprout tips. Proteinase inhibition studies revealed membrane-associated matrix metalloproteinase were utilized for sprout advancement and lumen expansion. Rho-associated kinase (p160ROCK) inhibition demonstrated that the generation of cell tension increased collagen matrix alterations. This study followed sprouting ECs within a 3D matrix and revealed that the advancing structures recognize and significantly alter their extracellular environment at the periphery of lumens as they progress.

  4. Optical and electron microscopy of WC-Co alloys

    SciTech Connect

    Yust, C S; Long, Jr, E L

    1982-02-01

    The microstructures of three commercial cobalt-bonded tungsten carbide alloys have been characterized by optical and electron microscopy and compared with a specially formulated reference alloy composed of tungsten carbide bonded by 6 wt % Co. The first alloy contained additions of chromium as chromium carbides, was similar in microstructure to the reference alloy, and contained secondary carbide grains retained from the chromium addition. An alloy containing metallic chromium also contained grains of the ternary carbide Co/sub 3/W/sub 3/C, or eta phase, which can be rationalized as having formed by reaction of the molten cobalt-chromium binder phase with the tungsten carbide matrix at the processing temperature. The third commercial alloy examined contained a coarse dendritic structure identified as a mixture of eta (Co/sub 3/W/sub 3/C) and chi (Co/sub 3/W/sub 9/C/sub 4/) phases. The reactions responsible for formation of the eta and chi phases in this alloy have not yet been determined.

  5. All-optical photoacoustic microscopy using a MEMS scanning mirror

    NASA Astrophysics Data System (ADS)

    Chen, Sung-Liang; Xie, Zhixing; Ling, Tao; Wei, Xunbin; Guo, L. Jay; Wang, Xueding

    2013-03-01

    It has been studied that a potential marker to obtain prognostic information about bladder cancer is tumor neoangiogenesis, which can be quantified by morphometric characteristics such as microvascular density. Photoacoustic microscopy (PAM) can render sensitive three-dimensional (3D) mapping of microvasculature, providing promise to evaluate the neoangiogenesis that is closely related to the diagnosis of bladder cancer. To ensure good image quality, it is desired to acquire bladder PAM images from its inside via the urethra, like conventional cystoscope. Previously, we demonstrated all-optical PAM systems using polymer microring resonators to detect photoacoustic signals and galvanometer mirrors for laser scanning. In this work, we build a miniature PAM system using a microelectromechanical systems (MEMS) scanning mirror, demonstrating a prototype of an endoscopic PAM head capable of high imaging quality of the bladder. The system has high resolutions of 17.5 μm in lateral direction and 19 μm in the axial direction at a distance of 5.4 mm. Images of printed grids and the 3D structure of microvasculature in animal bladders ex vivo by the system are demonstrated.

  6. Refractive Optics for Hard X-ray Transmission Microscopy

    SciTech Connect

    Simon, M.; Last, A.; Mohr, J.; Nazmov, V.; Reznikova, E.; Ahrens, G.; Voigt, A.

    2011-09-09

    For hard x-ray transmission microscopy at photon energies higher than 15 keV we design refractive condenser and imaging elements to be used with synchrotron light sources as well as with x-ray tube sources. The condenser lenses are optimized for low x-ray attenuation--resulting in apertures greater than 1 mm--and homogeneous intensity distribution on the detector plane, whereas the imaging enables high-resolution (<100 nm) full-field imaging. To obtain high image quality at reasonable exposure times, custom-tailored matched pairs of condenser and imaging lenses are being developed. The imaging lenses (compound refractive lenses, CRLs) are made of SU-8 negative resist by deep x-ray lithography. SU-8 shows high radiation stability. The fabrication technique enables high-quality lens structures regarding surface roughness and arrangement precision with arbitrary 2D geometry. To provide point foci, crossed pairs of lenses are used. Condenser lenses have been made utilizing deep x-ray lithographic patterning of thick SU-8 layers, too, whereas in this case, the aperture is limited due to process restrictions. Thus, in terms of large apertures, condenser lenses made of structured and rolled polyimide film are more attractive. Both condenser types, x-ray mosaic lenses and rolled x-ray prism lenses (RXPLs), are considered to be implemented into a microscope setup. The x-ray optical elements mentioned above are characterized with synchrotron radiation and x-ray laboratory sources, respectively.

  7. Precision of light intensity measurement in biological optical microscopy.

    PubMed

    Bernas, Tytus; Barnes, David; Asem, Elikplimi K; Robinson, J Paul; Rajwa, Bartek

    2007-05-01

    Standardization and calibration of optical microscopy systems have become an important issue owing to the increasing role of biological imaging in high-content screening technology. The proper interpretation of data from high-content screening imaging experiments requires detailed information about the capabilities of the systems, including their available dynamic range, sensitivity and noise. Currently available techniques for calibration and standardization of digital microscopes commonly used in cell biology laboratories provide an estimation of stability and measurement precision (noise) of an imaging system at a single level of signal intensity. In addition, only the total noise level, not its characteristics (spectrum), is measured. We propose a novel technique for estimation of temporal variability of signal and noise in microscopic imaging. The method requires registration of a time series of images of any stationary biological specimen. The subsequent analysis involves a multi-step process, which separates monotonic, periodic and random components of every pixel intensity change in time. The technique allows simultaneous determination of dark, photonic and multiplicative components of noise present in biological measurements. Consequently, a respective confidence interval (noise level) is obtained for each level of signal. The technique is validated using test sets of biological images with known signal and noise characteristics. The method is also applied to assess uncertainty of measurement obtained with two CCD cameras in a wide-field microscope.

  8. Ex vivo imaging of human thyroid pathology using integrated optical coherence tomography and optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Zhou, Chao; Wang, Yihong; Aguirre, Aaron D.; Tsai, Tsung-Han; Cohen, David W.; Connolly, James L.; Fujimoto, James G.

    2010-01-01

    We evaluate the feasibility of optical coherence tomography (OCT) and optical coherence microscopy (OCM) for imaging of benign and malignant thyroid lesions ex vivo using intrinsic optical contrast. 34 thyroid gland specimens are imaged from 17 patients, covering a spectrum of pathology ranging from normal thyroid to benign disease/neoplasms (multinodular colloid goiter, Hashimoto's thyroiditis, and follicular adenoma) and malignant thyroid tumors (papillary carcinoma and medullary carcinoma). Imaging is performed using an integrated OCT and OCM system, with <4 μm axial resolution (OCT and OCM), and 14 μm (OCT) and <2 μm (OCM) transverse resolution. The system allows seamless switching between low and high magnifications in a way similar to traditional microscopy. Good correspondence is observed between optical images and histological sections. Characteristic features that suggest malignant lesions, such as complex papillary architecture, microfollicules, psammomatous calcifications, or replacement of normal follicular architecture with sheets/nests of tumor cells, can be identified from OCT and OCM images and are clearly differentiable from normal or benign thyroid tissues. With further development of needle-based imaging probes, OCT and OCM could be promising techniques to use for the screening of thyroid nodules and to improve the diagnostic specificity of fine needle aspiration evaluation.

  9. Numerical study of super-resolved optical microscopy with partly staggered beams

    NASA Astrophysics Data System (ADS)

    He, Jinping; Wang, Nan; Kobayashi, Takayoshi

    2016-12-01

    The resolving power of optical microscopy involving two or even more beams, such as pump-probe microscopy and nonlinear optical microscopy, can be enhanced both laterally and longitudinally with partly staggered beams. A numerical study of the new super-resolution imaging technology is performed with vector diffraction theory. The influence of polarization is discussed. A resolving power of sub-100 nm and sub-300 nm in the lateral and longitudinal directions, respectively, is achievable.

  10. Neural imaging in songbirds using fiber optic fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Nooshabadi, Fatemeh; Hearn, Gentry; Lints, Thierry; Maitland, Kristen C.

    2012-02-01

    The song control system of juvenile songbirds is an important model for studying the developmental acquisition and generation of complex learned vocal motor sequences, two processes that are fundamental to human speech and language. To understand the neural mechanisms underlying song production, it is critical to characterize the activity of identified neurons in the song control system when the bird is singing. Neural imaging in unrestrained singing birds, although technically challenging, will advance our understanding of neural ensemble coding mechanisms in this system. We are exploring the use of a fiber optic microscope for functional imaging in the brain of behaving and singing birds in order to better understand the contribution of a key brain nucleus (high vocal center nucleus; HVC) to temporal aspects of song motor control. We have constructed a fluorescence microscope with LED illumination, a fiber bundle for transmission of fluorescence excitation and emission light, a ~2x GRIN lens, and a CCD for image acquisition. The system has 2 μm resolution, 375 μm field of view, 200 μm working distance, and 1 mm outer diameter. As an initial characterization of this setup, neurons in HVC were imaged using the fiber optic microscope after injection of quantum dots or fluorescent retrograde tracers into different song nuclei. A Lucid Vivascope confocal microscope was used to confirm the imaging results. Long-term imaging of the activity of these neurons in juvenile birds during singing may lead us to a better understanding of the central motor codes for song and the central mechanism by which auditory experience modifies song motor commands to enable vocal learning and imitation.

  11. Optical diagnosis of mammary ductal carcinoma using advanced optical technology

    NASA Astrophysics Data System (ADS)

    Wu, Yan; Fu, Fangmeng; Lian, Yuane; Nie, Yuting; Zhuo, Shuangmu; Wang, Chuan; Chen, Jianxin

    2015-02-01

    Clinical imaging techniques for diagnosing breast cancer mainly include X-ray mammography, ultrasound, and magnetic resonance imaging (MRI), which have respective drawbacks. Multiphoton microscopy (MPM) has become a potentially attractive optical technique to bridge the current gap in clinical utility. In this paper, MPM was used to image normal and ductal cancerous breast tissues, based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG). Our results showed that MPM has the ability to exhibit the microstructure of normal breast tissue, ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) lesions at the molecular level comparable to histopathology. These findings indicate that, with integration of MPM into currently accepted clinical imaging system, it has the potential to make a real-time histological diagnosis of mammary ductal carcinoma in vivo.

  12. Recent Advances in Miniaturized Optical Gyroscopes

    NASA Astrophysics Data System (ADS)

    Dell'Olio, F.; Tatoli, T.; Ciminelli, C.; Armenise, M. N.

    2014-03-01

    Low-cost chip-scale optoelectronic gyroscopes having a resolution ≤ 10 °/h and a good reliability also in harsh environments could have a strong impact on the medium/high performance gyro market, which is currently dominated by well-established bulk optical angular velocity sensors. The R&D activity aiming at the demonstration of those miniaturized sensors is crucial for aerospace/defense industry, and thus it is attracting an increasing research effort and notably funds. In this paper the recent technological advances on the compact optoelectronic gyroscopes with low weight and high energy saving are reviewed. Attention is paid to both the so-called gyroscope-on-a-chip, which is a novel sensor, at the infantile stage, whose optical components are monolithically integrated on a single indium phosphide chip, and to a new ultra-high Q ring resonator for gyro applications with a configuration including a 1D photonic crystal in the resonant path. The emerging field of the gyros based on passive ring cavities, which have already shown performance comparable with that of optical fiber gyros, is also discussed.

  13. Transmission Electron Microscopy Advances Reveal Subtle Comet Dust Differences

    NASA Astrophysics Data System (ADS)

    Ishii, H. A.; Bradley, J. P.

    2015-07-01

    TEM advances in multi-SDD-detector EDX mapping applied to Wild 2 dust and likely-cometary CP IDPs demonstrates chondritic fine-grained material at terminal particles is unlike GEMS and consistent with debris generated during the deceleration process.

  14. Modeling Graphene Contrast on Copper Surfaces Using Optical Microscopy

    DTIC Science & Technology

    2014-10-01

    requirement for transfer. Atomic force microscopy was used to determine copper oxide thickness, and a Matlab model based on Fresnel theory was used to...consuming process involving specialized techniques such as atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron...laser was used as the excitation source. A Cypher SPM in noncontact mode was used for topography and phase imaging characterization. 2.4 Broadband

  15. Recent advances in submolecular resolution with scanning probe microscopy.

    PubMed

    Gross, Leo

    2011-04-01

    Recently scanning probe microscopy has made tremendous progress in imaging organic molecules with high lateral resolution. Atoms and bonds within individual molecules have been clearly resolved, indicating the exciting potential of this technique for studying molecular structures, bonding within and between molecules, molecular conformational changes and chemical reactions at the single-molecule level. It turns out that the key step enabling such studies is an atomically controlled functionalization of the microscope tip. In this Perspective, the different techniques used for high-resolution molecular imaging, their implementations, advantages and limitations are described, and possible scientific areas of applications are discussed.

  16. Advances in optics for biotechnology, medicine and surgery

    PubMed Central

    Fitzmaurice, Maryann; Pogue, Brian W.; Tearney, Guillermo J.; Tunnell, James W.; Yang, Changhuei

    2014-01-01

    The guest editors introduce a Biomedical Optics Express feature issue that includes contributions from participants at the 2013 conference on Advances in Optics for Biotechnology, Medicine and Surgery XIII. PMID:24575348

  17. Advances in optics for biotechnology, medicine and surgery.

    PubMed

    Fitzmaurice, Maryann; Pogue, Brian W; Tearney, Guillermo J; Tunnell, James W; Yang, Changhuei

    2014-02-01

    The guest editors introduce a Biomedical Optics Express feature issue that includes contributions from participants at the 2013 conference on Advances in Optics for Biotechnology, Medicine and Surgery XIII.

  18. Automated interferometric synthetic aperture microscopy and computational adaptive optics for improved optical coherence tomography.

    PubMed

    Xu, Yang; Liu, Yuan-Zhi; Boppart, Stephen A; Carney, P Scott

    2016-03-10

    In this paper, we introduce an algorithm framework for the automation of interferometric synthetic aperture microscopy (ISAM). Under this framework, common processing steps such as dispersion correction, Fourier domain resampling, and computational adaptive optics aberration correction are carried out as metrics-assisted parameter search problems. We further present the results of this algorithm applied to phantom and biological tissue samples and compare with manually adjusted results. With the automated algorithm, near-optimal ISAM reconstruction can be achieved without manual adjustment. At the same time, the technical barrier for the nonexpert using ISAM imaging is also significantly lowered.

  19. Quantitative analysis of autophagy using advanced 3D fluorescence microscopy.

    PubMed

    Changou, Chun A; Wolfson, Deanna L; Ahluwalia, Balpreet Singh; Bold, Richard J; Kung, Hsing-Jien; Chuang, Frank Y S

    2013-05-03

    Prostate cancer is the leading form of malignancies among men in the U.S. While surgery carries a significant risk of impotence and incontinence, traditional chemotherapeutic approaches have been largely unsuccessful. Hormone therapy is effective at early stage, but often fails with the eventual development of hormone-refractory tumors. We have been interested in developing therapeutics targeting specific metabolic deficiency of tumor cells. We recently showed that prostate tumor cells specifically lack an enzyme (argininosuccinate synthase, or ASS) involved in the synthesis of the amino acid arginine(1). This condition causes the tumor cells to become dependent on exogenous arginine, and they undergo metabolic stress when free arginine is depleted by arginine deiminase (ADI)(1,10). Indeed, we have shown that human prostate cancer cells CWR22Rv1 are effectively killed by ADI with caspase-independent apoptosis and aggressive autophagy (or macroautophagy)(1,2,3). Autophagy is an evolutionarily-conserved process that allows cells to metabolize unwanted proteins by lysosomal breakdown during nutritional starvation(4,5). Although the essential components of this pathway are well-characterized(6,7,8,9), many aspects of the molecular mechanism are still unclear - in particular, what is the role of autophagy in the death-response of prostate cancer cells after ADI treatment? In order to address this question, we required an experimental method to measure the level and extent of autophagic response in cells - and since there are no known molecular markers that can accurately track this process, we chose to develop an imaging-based approach, using quantitative 3D fluorescence microscopy(11,12). Using CWR22Rv1 cells specifically-labeled with fluorescent probes for autophagosomes and lysosomes, we show that 3D image stacks acquired with either widefield deconvolution microscopy (and later, with super-resolution, structured-illumination microscopy) can clearly capture the early

  20. Near-Field Optical Microscopy and Spectroscopy with Pointed Probes

    DTIC Science & Technology

    2006-01-01

    metal nanostructure can be viewed as an optical antenna . Of course, the efficiency depends on the material composition and the geometry of the...nanostructure. A simple form of optical antenna is a single ellipsoidal particle. This particle ex- hibits a distinct resonance for which the field...Grober RD, Schoelkopf RJ, Prober DE. 1997. Optical antenna : towards a unity efficiency near-field optical probe. Appl. Phys. Lett. 70:1354 54. Farahani

  1. Subsurface Optical Microscopy of Coarse Grain Spinels. Phase 1

    DTIC Science & Technology

    2013-12-01

    A 456 nm LED line bar illuminated in figure 15 and a Xenon fiber optic bar illuminator is shown for figure 16. The optical in situ or subsurface ... imaging of coarse grain spinels and AlONs is optically more complex than expected. An overhead view of the side illumination field is shown in figure 20

  2. Multiscale imaging of human thyroid pathologies using integrated optical coherence tomography (OCT) and optical coherence microscopy (OCM)

    NASA Astrophysics Data System (ADS)

    Zhou, Chao; Wang, Yihong; Aguirre, Aaron D.; Tsai, Tsung-Han; Cohen, David W.; Connolly, James L.; Fujimoto, James G.

    2010-02-01

    We evaluate the feasibility of optical coherence tomography (OCT) and optical coherence microscopy (OCM) for imaging of benign and malignant thyroid lesions ex vivo using intrinsic optical contrast. Thirty four thyroid gland specimens were imaged from 17 patients, covering a spectrum of pathology, ranging from normal thyroid to neoplasia and benign disease. The integrated OCT and OCM imaging system allows seamlessly switching between low and high magnifications, in a way similar to traditional microscopy. Good correspondence was observed between optical images and histological sections. The results provide a basis for interpretation of future OCT and OCM images of the thyroid tissues and suggest the possibility of future in vivo evaluation of thyroid pathology.

  3. Plasma etching for advanced polymer optical devices

    NASA Astrophysics Data System (ADS)

    Bitting, Donald S.

    Plasma etching is a common microfabrication technique which can be applied to polymers as well as glasses, metals, and semiconductors. The fabrication of low loss and reliable polymer optical devices commonly makes use of advanced microfabrication processing techniques similar in nature to those utilized in standard semiconductor fabrication technology. Among these techniques, plasma/reactive ion etching is commonly used in the formation of waveguiding core structures. Plasma etching is a powerful processing technique with many potential applications in the emerging field of polymer optical device fabrication. One such promising application explored in this study is in the area of thin film-substrate adhesion enhancement. Two approaches involving plasma processing were evaluated to improve substrate-thin film adhesion in the production of polymer waveguide optical devices. Plasma treatment of polymer substrates such as polycarbonate has been studied to promote the adhesion of fluoropolymer thin film coatings for waveguide device fabrication. The effects of blanket oxygen plasma etchback on substrate, microstructural substrate feature formation, and the long term performance and reliability of these methods were investigated. Use of a blanket oxygen plasma to alter the polycarbonate surface prior to fluoropolymer casting was found to have positive but limited capability to improve the adhesive strength between these polymers. Experiments show a strong correlation between surface roughness and adhesion strength. The formation of small scale surface features using microlithography and plasma etching on the polycarbonate surface proved to provide outstanding adhesion strength when compared to any other known treatment methods. Long term environmental performance testing of these surface treatment methods provided validating data. Test results showed these process approaches to be effective solutions to the problem of adhesion between hydrocarbon based polymer

  4. Integrated optical coherence tomography and optical coherence microscopy imaging of human pathology

    NASA Astrophysics Data System (ADS)

    Lee, Hsiang-Chieh; Zhou, Chao; Wang, Yihong; Aquirre, Aaron D.; Tsai, Tsung-Han; Cohen, David W.; Connolly, James L.; Fujimoto, James G.

    2010-02-01

    Excisional biopsy is the current gold standard for disease diagnosis; however, it requires a relatively long processing time and it may also suffer from unacceptable false negative rates due to sampling errors. Optical coherence tomography (OCT) is a promising imaging technique that provide real-time, high resolution and three-dimensional (3D) images of tissue morphology. Optical coherence microscopy (OCM) is an extension of OCT, combining both the coherence gating and the confocal gating techniques. OCM imaging achieves cellular resolution with deeper imaging depth compared to confocal microscopy. An integrated OCT/OCM imaging system can provide co-registered multiscale imaging of tissue morphology. 3D-OCT provides architectural information with a large field of view and can be used to find regions of interest; while OCM provides high magnification to enable cellular imaging. The integrated OCT/OCM system has an axial resolution of <4um and transverse resolutions of 14um and <2um for OCT and OCM, respectively. In this study, a wide range of human pathologic specimens, including colon (58), thyroid (43), breast (34), and kidney (19), were imaged with OCT and OCM within 2 to 6 hours after excision. The images were compared with H & E histology to identify characteristic features useful for disease diagnosis. The feasibility of visualizing human pathology using integrated OCT/OCM was demonstrated in the pathology laboratory settings.

  5. Thin dielectric film thickness determination by advanced transmission electron microscopy

    SciTech Connect

    Diebold, A.C.; Foran, B.; Kisielowski, C.; Muller, D.; Pennycook, S.; Principe, E.; Stemmer, S.

    2003-09-01

    High Resolution Transmission Electron Microscopy (HR-TEM) has been used as the ultimate method of thickness measurement for thin films. The appearance of phase contrast interference patterns in HR-TEM images has long been confused as the appearance of a crystal lattice by non-specialists. Relatively easy to interpret crystal lattice images are now directly observed with the introduction of annular dark field detectors for scanning TEM (STEM). With the recent development of reliable lattice image processing software that creates crystal structure images from phase contrast data, HR-TEM can also provide crystal lattice images. The resolution of both methods was steadily improved reaching now into the sub Angstrom region. Improvements in electron lens and image analysis software are increasing the spatial resolution of both methods. Optimum resolution for STEM requires that the probe beam be highly localized. In STEM, beam localization is enhanced by selection of the correct aperture. When STEM measurement is done using a highly localized probe beam, HR-TEM and STEM measurement of the thickness of silicon oxynitride films agree within experimental error. In this paper, the optimum conditions for HR-TEM and STEM measurement are discussed along with a method for repeatable film thickness determination. The impact of sample thickness is also discussed. The key result in this paper is the proposal of a reproducible method for film thickness determination.

  6. Advancing ovarian folliculometry with selective plane illumination microscopy

    PubMed Central

    Lin, Hsiao-Chun Amy; Dutta, Rahul; Mandal, Subhamoy; Kind, Alexander; Schnieke, Angelika; Razansky, Daniel

    2016-01-01

    Determination of ovarian status and follicle monitoring are common methods of diagnosing female infertility. We evaluated the suitability of selective plane illumination microscopy (SPIM) for the study of ovarian follicles. The large field of view and fast acquisition speed of our SPIM system enables rendering of volumetric image stacks from intact whole porcine ovarian follicles, clearly visualizing follicular features including follicle volume and average diameter (70 μm–2.5 mm), their spherical asymmetry parameters, size of developing cumulus oophorus complexes (40 μm–110 μm), and follicular wall thickness (90 μm–120 μm). Follicles at all developmental stages were identified. A distribution of the theca thickness was measured for each follicle, and a relationship between these distributions and the stages of follicular development was discerned. The ability of the system to non-destructively generate sub-cellular resolution 3D images of developing follicles, with excellent image contrast and high throughput capacity compared to conventional histology, suggests that it can be used to monitor follicular development and identify structural abnormalities indicative of ovarian ailments. Accurate folliculometric measurements provided by SPIM images can immensely help the understanding of ovarian physiology and provide important information for the proper management of ovarian diseases. PMID:27905503

  7. Advancing ovarian folliculometry with selective plane illumination microscopy

    NASA Astrophysics Data System (ADS)

    Lin, Hsiao-Chun Amy; Dutta, Rahul; Mandal, Subhamoy; Kind, Alexander; Schnieke, Angelika; Razansky, Daniel

    2016-12-01

    Determination of ovarian status and follicle monitoring are common methods of diagnosing female infertility. We evaluated the suitability of selective plane illumination microscopy (SPIM) for the study of ovarian follicles. The large field of view and fast acquisition speed of our SPIM system enables rendering of volumetric image stacks from intact whole porcine ovarian follicles, clearly visualizing follicular features including follicle volume and average diameter (70 μm–2.5 mm), their spherical asymmetry parameters, size of developing cumulus oophorus complexes (40 μm–110 μm), and follicular wall thickness (90 μm–120 μm). Follicles at all developmental stages were identified. A distribution of the theca thickness was measured for each follicle, and a relationship between these distributions and the stages of follicular development was discerned. The ability of the system to non-destructively generate sub-cellular resolution 3D images of developing follicles, with excellent image contrast and high throughput capacity compared to conventional histology, suggests that it can be used to monitor follicular development and identify structural abnormalities indicative of ovarian ailments. Accurate folliculometric measurements provided by SPIM images can immensely help the understanding of ovarian physiology and provide important information for the proper management of ovarian diseases.

  8. High-resolution electron microscopy of advanced materials

    SciTech Connect

    Mitchell, T.E.; Kung, H.H.; Sickafus, K.E.; Gray, G.T. III; Field, R.D.; Smith, J.F.

    1997-11-01

    This final report chronicles a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The High-Resolution Electron Microscopy Facility has doubled in size and tripled in quality since the beginning of the three-year period. The facility now includes a field-emission scanning electron microscope, a 100 kV field-emission scanning transmission electron microscope (FE-STEM), a 300 kV field-emission high-resolution transmission electron microscope (FE-HRTEM), and a 300 kV analytical transmission electron microscope. A new orientation imaging microscope is being installed. X-ray energy dispersive spectrometers for chemical analysis are available on all four microscopes; parallel electron energy loss spectrometers are operational on the FE-STEM and FE-HRTEM. These systems enable evaluation of local atomic bonding, as well as chemical composition in nanometer-scale regions. The FE-HRTEM has a point-to-point resolution of 1.6 {angstrom}, but the resolution can be pushed to its information limit of 1 {angstrom} by computer reconstruction of a focal series of images. HRTEM has been used to image the atomic structure of defects such as dislocations, grain boundaries, and interfaces in a variety of materials from superconductors and ferroelectrics to structural ceramics and intermetallics.

  9. Advance in orientation microscopy: quantitative analysis of nanocrystalline structures.

    PubMed

    Seyring, Martin; Song, Xiaoyan; Rettenmayr, Markus

    2011-04-26

    The special properties of nanocrystalline materials are generally accepted to be a consequence of the high density of planar defects (grain and twin boundaries) and their characteristics. However, until now, nanograin structures have not been characterized with similar detail and statistical relevance as coarse-grained materials, due to the lack of an appropriate method. In the present paper, a novel method based on quantitative nanobeam diffraction in transmission electron microscopy (TEM) is presented to determine the misorientation of adjacent nanograins and subgrains. Spatial resolution of <5 nm can be achieved. This method is applicable to characterize orientation relationships in wire, film, and bulk materials with nanocrystalline structures. As a model material, nanocrystalline Cu is used. Several important features of the nanograin structure are discovered utilizing quantitative analysis: the fraction of twin boundaries is substantially higher than that observed in bright-field images in the TEM; small angle grain boundaries are prominent; there is an obvious dependence of the grain boundary characteristics on grain size distribution and mean grain size.

  10. Atomic force microscopy as an advanced tool in neuroscience

    PubMed Central

    Jembrek, Maja Jazvinšćak; Šimić, Goran; Hof, Patrick R.; Šegota, Suzana

    2015-01-01

    This review highlights relevant issues about applications and improvements of atomic force microscopy (AFM) toward a better understanding of neurodegenerative changes at the molecular level with the hope of contributing to the development of effective therapeutic strategies for neurodegenerative illnesses. The basic principles of AFM are briefly discussed in terms of evaluation of experimental data, including the newest PeakForce Quantitative Nanomechanical Mapping (QNM) and the evaluation of Young’s modulus as the crucial elasticity parameter. AFM topography, revealed in imaging mode, can be used to monitor changes in live neurons over time, representing a valuable tool for high-resolution detection and monitoring of neuronal morphology. The mechanical properties of living cells can be quantified by force spectroscopy as well as by new AFM. A variety of applications are described, and their relevance for specific research areas discussed. In addition, imaging as well as non-imaging modes can provide specific information, not only about the structural and mechanical properties of neuronal membranes, but also on the cytoplasm, cell nucleus, and particularly cytoskeletal components. Moreover, new AFM is able to provide detailed insight into physical structure and biochemical interactions in both physiological and pathophysiological conditions. PMID:28123795

  11. Sub-40 fs, 1060-nm Yb-fiber laser enhances penetration depth in nonlinear optical microscopy of human skin

    NASA Astrophysics Data System (ADS)

    Balu, Mihaela; Saytashev, Ilyas; Hou, Jue; Dantus, Marcos; Tromberg, Bruce J.

    2015-12-01

    Advancing the practical utility of nonlinear optical microscopy requires continued improvement in imaging depth and contrast. We evaluated second-harmonic generation (SHG) and third-harmonic generation images from ex vivo human skin and showed that a sub-40 fs, 1060-nm Yb-fiber laser can enhance SHG penetration depth by up to 80% compared to a >100 fs, 800 nm Ti:sapphire source. These results demonstrate the potential of fiber-based laser systems to address a key performance limitation related to nonlinear optical microscopy (NLOM) technology while providing a low-barrier-to-access alternative to Ti:sapphire sources that could help accelerate the movement of NLOM into clinical practice.

  12. Nanofabrication by advanced electron microscopy using intense and focused beam∗

    PubMed Central

    Furuya, Kazuo

    2008-01-01

    The nanogrowth and nanofabrication of solid substances using an intense and focused electron beam are reviewed in terms of the application of scanning and transmission electron microscopy (SEM, TEM and STEM) to control the size, position and structure of nanomaterials. The first example discussed is the growth of freestanding nanotrees on insulator substrates by TEM. The growth process of the nanotrees was observed in situ and analyzed by high-resolution TEM (HRTEM) and was mainly controlled by the intensity of the electron beam. The second example is position- and size-controlled nanofabrication by STEM using a focused electron beam. The diameters of the nanostructures grown ranged from 4 to 20 nm depending on the size of the electron beam. Magnetic nanostructures were also obtained using an iron-containing precursor gas, Fe(CO)5. The freestanding iron nanoantennas were examined by electron holography. The magnetic field was observed to leak from the nanostructure body which appeared to act as a ‘nanomagnet’. The third example described is the effect of a vacuum on the size and growth process of fabricated nanodots containing W in an ultrahigh-vacuum field-emission TEM (UHV-FE-TEM). The size of the dots can be controlled by changing the dose of electrons and the partial pressure of the precursor. The smallest particle size obtained was about 1.5 nm in diameter, which is the smallest size reported using this method. Finally, the importance of a smaller probe and a higher electron-beam current with atomic resolution is emphasized and an attempt to develop an ultrahigh-vacuum spherical aberration corrected STEM (Cs-corrected STEM) at NIMS is reported. PMID:27877936

  13. High precision deflection measurement of microcantilever in an optical pickup head based atomic force microscopy

    SciTech Connect

    Lee, Sang Heon

    2012-11-15

    This paper presents the methodology to measure the precise deflection of microcantilever in an optical pickup head based atomic force microscopy. In this paper, three types of calibration methods have been proposed: full linearization, sectioned linearization, and the method based on astigmatism. In addition, the probe heads for easy calibration of optical pickup head and fast replacement of optical pickup head have been developed. The performances of each method have been compared through a set of experiments and constant height mode operation which was not possible in the optical pickup head based atomic force microscopy has been carried out successfully.

  14. Optical microscopy in the study of supramolecular structure of protein systems

    NASA Astrophysics Data System (ADS)

    Buzoverya, M. E.; Shishpor, I. V.

    2016-10-01

    Fluctuations of the supramolecular structure of albumin facies are analyzed. Two stable states of the supramolecular structure of facies are revealed at room temperature. Optical microscopy is used to assess dynamic character of the supramolecular structure of human serum albumin.

  15. Wide-field optical sectioning for live-tissue imaging by plane-projection multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    Yu, Jiun-Yann; Kuo, Chun-Hung; Holland, Daniel B.; Chen, Yenyu; Ouyang, Mingxing; Blake, Geoffrey A.; Zadoyan, Ruben; Guo, Chin-Lin

    2011-11-01

    Optical sectioning provides three-dimensional (3D) information in biological tissues. However, most imaging techniques implemented with optical sectioning are either slow or deleterious to live tissues. Here, we present a simple design for wide-field multiphoton microscopy, which provides optical sectioning at a reasonable frame rate and with a biocompatible laser dosage. The underlying mechanism of optical sectioning is diffuser-based temporal focusing. Axial resolution comparable to confocal microscopy is theoretically derived and experimentally demonstrated. To achieve a reasonable frame rate without increasing the laser power, a low-repetition-rate ultrafast laser amplifier was used in our setup. A frame rate comparable to that of epifluorescence microscopy was demonstrated in the 3D imaging of fluorescent protein expressed in live epithelial cell clusters. In this report, our design displays the potential to be widely used for video-rate live-tissue and embryo imaging with axial resolution comparable to laser scanning microscopy.

  16. Gold Coating of Fiber Tips in Near-Field Scanning Optical Microscopy

    NASA Technical Reports Server (NTRS)

    Vikram, Chandra S.; Witherow, William K.

    2000-01-01

    We report what is believed to be the first experimental demonstration of gold coating by a chemical baking process on tapered fiber tips used in near-field scanning optical microscopy. Many tips can be simultaneously coated.

  17. Three-dimensional microscopy by optical scanning holography

    NASA Astrophysics Data System (ADS)

    Poon, Ting-Chung; Doh, Kyu B.; Schilling, Bradley W.; Wu, Ming H.; Shinoda, Kazunori K.; Suzuki, Yoshiji

    1995-05-01

    We first briefly review a new 3D imaging technique called optical scanning holography (OSH). We then discuss the technique's 3D holographic magnification in the context of optical scanning and digital reconstruction. Finally, we demonstrate the 3D imaging capability of OSH by holographically recording two planar objects at different depths and reconstructing the hologram digitally.

  18. Low-cost multimodal light sheet microscopy for optically cleared tissues and living specimens

    NASA Astrophysics Data System (ADS)

    Rouger, Vincent; Alchini, Ricardo; Kazarine, Alexei; Gopal, Angelica A.; Girouard, Marie-Pier; Fournier, Alyson E.; Wiseman, Paul W.

    2016-12-01

    Light sheet microscopy techniques have expanded with designs to address many new applications. Due to rapid advancements in computing power, camera/detector technologies, and tissue clearing techniques, light sheet methods are becoming increasingly popular for biomedical imaging applications at the cellular and tissue levels. Light sheet imaging modalities couple rapid imaging rates, low-levels of phototoxicity, and excellent signal to noise ratios, contributing to their popularity for experimental biology. However, the current major limitation of light sheet microscopy arises from optical aberrations, with the main drawback being the defocusing introduced by refractive index variations that accompany clearing techniques. Here, we propose an inexpensive and easy to build light sheet based instrumentation to overcome this limitation by optomechanically decoupling the sample scanning movement from the detection step. Our solution is relatively simple to implement and also provides increased modularity by using a swappable excitation arm. This expands the range of samples we can image on a single system, from high resolution for single cells at μm spatial resolution, to tissues with mm spatial resolution. We demonstrate our approach, using the system to image iDISCO cleared embryos and sciatic nerves, and provide the full three-dimensional reconstruction of these objects in minutes.

  19. Advanced Integrated Optical Signal Processing Components.

    NASA Astrophysics Data System (ADS)

    Rastani, Kasra

    This research was aimed at the development of advanced integrated optical components suitable for devices capable of processing multi-dimensional inputs. In such processors, densely packed waveguide arrays with low crosstalk are needed to provide dissection of the information that has been partially processed. Waveguide arrays also expand the information in the plane of the processor while maintaining its coherence. Rib waveguide arrays with low loss, high mode confinement and highly uniform surface quality (660 elements, 8 μm wide, 1 μm high, and 1 cm long with 2 mu m separations) were fabricated on LiNbO _3 substrates through the ion beam milling technique. A novel feature of the multi-dimensional IO processor architecture proposed herein is the implementation of large area uniform outcoupling (with low to moderate outcoupling efficiencies) from rib waveguide arrays in order to access the third dimension of the processor structure. As a means of outcoupling, uniform surface gratings (2 μm and 4 μm grating periods, 0.05 μm high and 1 mm long) with low outcoupling efficiencies (of approximately 2-18%/mm) were fabricated on the nonuniform surface of the rib waveguide arrays. As a practical technique of modulating the low outcoupling efficiencies of the surface gratings, it was proposed to alter the period of the grating as a function of position along each waveguide. Large aperture (2.5 mm) integrated lenses with short positive focal lengths (1.2-2.5 cm) were developed through a modification of the titanium-indiffused proton exchanged (TIPE) technique. Such integrated lenses were fabricated by increasing the refractive index of the slab waveguides by the TIPE process while maintaining the refractive index of the lenses at the lower level of Ti:LiNbO _3 waveguide. By means of curvature reversal of the integrated lenses, positive focal length lenses have been fabricated while providing high mode confinement for the slab waveguide. The above elements performed as

  20. Advanced optical diagnostics in hypersonic research

    NASA Astrophysics Data System (ADS)

    Cattolica, Robert J.

    1988-10-01

    The renewed emphasis on hypersonic research has stimulated a resurgence of interest in experimental methods for the study of high-speed flows. Improvement in the physical and chemical models used in computational fluid dynamic simulation of hypersonic flows requires a modern experimental data base. Optical diagnostics provide the capability to make nonintrusive measurements of density, temperature, velocity, and species concentration in hypersonic flows. The short test time available in hypersonic wind tunnels or flight experiments necessitates spectroscopic methods capable of producing high signal levels. Fluorescence methods based on laser or electron-beam excitation satisfy this requirement. For flight experiments, electron-beam excitation offers a number of advantages over laser excitation that include small device size, high electrical efficiency, and multiple-state and species-selective excitation. Disadvantages of the electron beam fluorescence (EBF) technique included a complex excitation mechanism and some limitations in high-density applications. Laser fluorescence methods (LIF) have been developed extensively in recent years for combustion research, but need further advances in miniaturization of lasers for application to in-flight hypersonic combustion and aerodynamic experiments. Both techniques require a fundamental understanding of the complications introduced by physical effects such as energy transfer and quenching of the fluorescence signal. With modern electro-optic instrumentation it is now possible to examine in detail the influence of these phenomena on EBF and LIF fluorescence spectra in the laboratory and to extend these measurement techniques for use in flight research. To illustrate some of the research required to develop these methods to address issues relevent to hypersonic flight, examples of experiments on the use of EBF and LIF spectroscopy for the measurement of nitric oxide concentration are presented.

  1. Super-resolution optical microscopy study of telomere structure

    NASA Astrophysics Data System (ADS)

    Phipps, Mary Lisa; Goodwin, Peter M.; Martinez, Jennifer S.; Goodwin, Edwin H.

    2016-09-01

    Chromosome ends are shielded from exonucleolytic attack and inappropriate end-joining by terminal structures called telomeres; these structures are potential targets for anticancer drugs. Telomeres are composed of a simple DNA sequence (5‧-TTAGGG-3‧ in humans) repeated more than a thousand times, a short 3‧ single-stranded overhang, and numerous proteins. Electron microscopy has shown that the 3‧ overhang pairs with the complementary strand at an internal site creating a small displacement loop and a large double-stranded "t-loop." Our goal is to determine whether all telomeres adopt the t-loop configuration, or whether there are two or more distinct configurations. Progress in optimizing super-resolution (SR) microscopy for this ongoing investigation is reported here. Results suggest that under certain conditions sample preparation procedures may disrupt chromatin by causing loss of nucleosomes. This finding may limit the use of SR microscopy in telomere studies.

  2. Pulse front adaptive optics in two-photon microscopy.

    PubMed

    Sun, Bangshan; Salter, Patrick S; Booth, Martin J

    2015-11-01

    Adaptive optics has been extensively studied for the correction of phase front aberrations in optical systems. In systems using ultrafast lasers, distortions can also exist in the pulse front (contour of constant intensity in space and time), but until now their correction has been mostly unexplored due to technological limitations. In this Letter, we apply newly developed pulse front adaptive optics, for the first time to our knowledge, to practical compensation of a two-photon fluorescence microscope. With adaptive correction of the system-induced pulse front distortion, improvements beyond conventional phase correction are demonstrated.

  3. GPU-based computational adaptive optics for volumetric optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Tang, Han; Mulligan, Jeffrey A.; Untracht, Gavrielle R.; Zhang, Xihao; Adie, Steven G.

    2016-03-01

    Optical coherence tomography (OCT) is a non-invasive imaging technique that measures reflectance from within biological tissues. Current higher-NA optical coherence microscopy (OCM) technologies with near cellular resolution have limitations on volumetric imaging capabilities due to the trade-offs between resolution vs. depth-of-field and sensitivity to aberrations. Such trade-offs can be addressed using computational adaptive optics (CAO), which corrects aberration computationally for all depths based on the complex optical field measured by OCT. However, due to the large size of datasets plus the computational complexity of CAO and OCT algorithms, it is a challenge to achieve high-resolution 3D-OCM reconstructions at speeds suitable for clinical and research OCM imaging. In recent years, real-time OCT reconstruction incorporating both dispersion and defocus correction has been achieved through parallel computing on graphics processing units (GPUs). We add to these methods by implementing depth-dependent aberration correction for volumetric OCM using plane-by-plane phase deconvolution. Following both defocus and aberration correction, our reconstruction algorithm achieved depth-independent transverse resolution of 2.8 um, equal to the diffraction-limited focal plane resolution. We have translated the CAO algorithm to a CUDA code implementation and tested the speed of the software in real-time using two GPUs - NVIDIA Quadro K600 and Geforce TITAN Z. For a data volume containing 4096×256×256 voxels, our system's processing speed can keep up with the 60 kHz acquisition rate of the line-scan camera, and takes 1.09 seconds to simultaneously update the CAO correction for 3 en face planes at user-selectable depths.

  4. Acute changes associated with electrode insertion measured with optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel X.; Lozzi, Andrea; Boretsky, Adam; Agrawal, Anant; Welle, Cristin G.

    2016-03-01

    Despite advances in functional neural imaging, penetrating microelectrodes provide the most direct interface for the extraction of neural signals from the nervous system and are a critical component of many high degree-of-freedom braincomputer interface devices. Electrode insertion is a traumatic event that elicits a complex neuroinflammatory response. In this investigation we applied optical coherence microscopy (OCM), particularly optical coherence angiography (OCA), to characterize the immediate tissue response during microelectrode insertion. Microelectrodes of varying dimension and footprint (one-, two-, and four-shank) were inserted into mouse motor cortex beneath a window after craniotomy surgery. The microelectrodes were inserted in 3-4 steps at 15-20°, with approximately 250 μm linear insertion distance for each step. Before insertion and between each step, OCM datasets were collected, including for quantitative capillary velocimetry. A cohort of control animals without microelectrode insertion was also imaged over a similar time period (2-3 hours). Mechanical tissue deformation was observed in all the experimental animals. The quantitative angiography results varied across animals, and were not correlated with device dimensions. In some cases, localized flow drop-out was observed in a small region surrounding the electrode, while in other instances a global disruption in flow occurred, perhaps as a result of large vessel compression caused by mechanical pressure. OCM is a tool that can be used in various neurophotonics applications, including quantification of the neuroinflammatory response to penetrating electrode insertion.

  5. Simultaneous topographical, electrical and optical microscopy of optoelectronic devices at the nanoscale.

    PubMed

    Kumar, Naresh; Zoladek-Lemanczyk, Alina; Guilbert, Anne A Y; Su, Weitao; Tuladhar, Sachetan M; Kirchartz, Thomas; Schroeder, Bob C; McCulloch, Iain; Nelson, Jenny; Roy, Debdulal; Castro, Fernando A

    2017-02-23

    Novel optoelectronic devices rely on complex nanomaterial systems where the nanoscale morphology and local chemical composition are critical to performance. However, the lack of analytical techniques that can directly probe these structure-property relationships at the nanoscale presents a major obstacle to device development. In this work, we present a novel method for non-destructive, simultaneous mapping of the morphology, chemical composition and photoelectrical properties with <20 nm spatial resolution by combining plasmonic optical signal enhancement with electrical-mode scanning probe microscopy. We demonstrate that this combined approach offers subsurface sensitivity that can be exploited to provide molecular information with a nanoscale resolution in all three spatial dimensions. By applying the technique to an organic solar cell device, we show that the inferred surface and subsurface composition distribution correlates strongly with the local photocurrent generation and explains macroscopic device performance. For instance, the direct measurement of fullerene phase purity can distinguish between high purity aggregates that lead to poor performance and lower purity aggregates (fullerene intercalated with polymer) that result in strong photocurrent generation and collection. We show that the reliable determination of the structure-property relationship at the nanoscale can remove ambiguity from macroscopic device data and support the identification of the best routes for device optimisation. The multi-parameter measurement approach demonstrated herein is expected to play a significant role in guiding the rational design of nanomaterial-based optoelectronic devices, by opening a new realm of possibilities for advanced investigation via the combination of nanoscale optical spectroscopy with a whole range of scanning probe microscopy modes.

  6. Noninvasive determination of optical lever sensitivity in atomic force microscopy

    SciTech Connect

    Higgins, M.J.; Proksch, R.; Sader, J.E.; Polcik, M.; Mc Endoo, S.; Cleveland, J.P.; Jarvis, S.P.

    2006-01-15

    Atomic force microscopes typically require knowledge of the cantilever spring constant and optical lever sensitivity in order to accurately determine the force from the cantilever deflection. In this study, we investigate a technique to calibrate the optical lever sensitivity of rectangular cantilevers that does not require contact to be made with a surface. This noncontact approach utilizes the method of Sader et al. [Rev. Sci. Instrum. 70, 3967 (1999)] to calibrate the spring constant of the cantilever in combination with the equipartition theorem [J. L. Hutter and J. Bechhoefer, Rev. Sci. Instrum. 64, 1868 (1993)] to determine the optical lever sensitivity. A comparison is presented between sensitivity values obtained from conventional static mode force curves and those derived using this noncontact approach for a range of different cantilevers in air and liquid. These measurements indicate that the method offers a quick, alternative approach for the calibration of the optical lever sensitivity.

  7. Quantitative optical microscopy: measurement of cellular biophysical features with a standard optical microscope.

    PubMed

    Phillips, Kevin G; Baker-Groberg, Sandra M; McCarty, Owen J T

    2014-04-07

    We describe the use of a standard optical microscope to perform quantitative measurements of mass, volume, and density on cellular specimens through a combination of bright field and differential interference contrast imagery. Two primary approaches are presented: noninterferometric quantitative phase microscopy (NIQPM), to perform measurements of total cell mass and subcellular density distribution, and Hilbert transform differential interference contrast microscopy (HTDIC) to determine volume. NIQPM is based on a simplified model of wave propagation, termed the paraxial approximation, with three underlying assumptions: low numerical aperture (NA) illumination, weak scattering, and weak absorption of light by the specimen. Fortunately, unstained cellular specimens satisfy these assumptions and low NA illumination is easily achieved on commercial microscopes. HTDIC is used to obtain volumetric information from through-focus DIC imagery under high NA illumination conditions. High NA illumination enables enhanced sectioning of the specimen along the optical axis. Hilbert transform processing on the DIC image stacks greatly enhances edge detection algorithms for localization of the specimen borders in three dimensions by separating the gray values of the specimen intensity from those of the background. The primary advantages of NIQPM and HTDIC lay in their technological accessibility using "off-the-shelf" microscopes. There are two basic limitations of these methods: slow z-stack acquisition time on commercial scopes currently abrogates the investigation of phenomena faster than 1 frame/minute, and secondly, diffraction effects restrict the utility of NIQPM and HTDIC to objects from 0.2 up to 10 (NIQPM) and 20 (HTDIC) μm in diameter, respectively. Hence, the specimen and its associated time dynamics of interest must meet certain size and temporal constraints to enable the use of these methods. Excitingly, most fixed cellular specimens are readily investigated with

  8. Exploring the limits of optical microscopy: live cell and superresolution fluorescence microscopy of HIV-1 Transfer Between T lymphocytes Across the Virological Synapse

    NASA Astrophysics Data System (ADS)

    McNerney, Gregory Paul

    Human immunodeficiency virus 1 (HIV-1) is a human retrovirus that efficiently, albeit gradually, overruns the immune system. An already infected T lymphocyte can latch onto another T lymphocyte whereby creating a virological synapse (VS); this junction drives viral assembly and transfer to the target cell in batches in an efficient, protective manor. My Ph.D. doctoral thesis focused on studying this transmission mechanism using advanced optical imaging modalities and the fully infectious fluorescent clone HIV Gag-iGFP. T lymphocytes are non-adherent cells (˜10 um thick) and the viral transmission process is fairly dynamic, hence we employed a custom spinning disk confocal microscope that revealed many interesting characteristics of this cooperative event. This methodology has low throughput as cell contact and transfer is at random. Optical tweezers was then added to the microscope to directly initiate cell contact at will. To assess when viral maturation occurs post-transfer, an optical assay based off of Forster resonance energy transfer was developed to monitor maturation. Structured illumination microscopy was further used to image the process at higher resolution and it showed that viral particles are not entering existing degradative compartments. Non-HIV-1 applications of the optical technologies are also reviewed.

  9. Fibre Fabry - Perot cavity-based aperture probe for near-field optical microscopy systems

    SciTech Connect

    Kulchin, Yurii N; Vitrik, O B; Bezverbnyi, A V; Pustovalov, E V; Kuchmizhak, A A; Nepomnyashchii, A V

    2011-03-31

    We report a theoretical analysis and experimental study of the possibility of producing a novel type of interferometric near-field aperture probe for near-field optical microscopy systems using a fibre Fabry - Perot microcavity with a nanometre-scale aperture made in one of its output mirrors. The probe ensures a spatial resolution no worse than {lambda}/14. (fibre optics)

  10. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy

    SciTech Connect

    Prabhakaran, Ramprashad; Joshi, Vineet V.; Rhodes, Mark A.; Schemer-Kohrn, Alan L.; Guzman, Anthony D.; Lavender, Curt A.

    2016-10-01

    The purpose of this document is to provide guidelines to prepare specimens of uranium alloyed with 10 weight percent molybdenum (U-10Mo) for optical metallography and scanning electron microscopy. This document also provides instructions to set up an optical microscope and a scanning electron microscope to analyze U-10Mo specimens and to obtain the required information.

  11. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy

    SciTech Connect

    Prabhakaran, Ramprashad; Joshi, Vineet V.; Rhodes, Mark A.; Schemer-Kohrn, Alan L.; Guzman, Anthony D.; Lavender, Curt A.

    2016-03-30

    The purpose of this document is to provide guidelines to prepare specimens of uranium alloyed with 10 weight percent molybdenum (U-10Mo) for optical metallography and scanning electron microscopy. This document also provides instructions to set up an optical microscope and a scanning electron microscope to analyze U-10Mo specimens and to obtain the required information.

  12. Sensorless adaptive optics and the effect of field of view in biological second harmonic generation microscopy

    NASA Astrophysics Data System (ADS)

    Vandendriessche, Stefaan; Vanbel, Maarten K.; Verbiest, Thierry

    2014-05-01

    In light of the population aging in many developed countries, there is a great economical interest in improving the speed and cost-efficiency of healthcare. Clinical diagnosis tools are key to these improvements, with biophotonics providing a means to achieve them. Standard optical microscopy of in vitro biological samples has been an important diagnosis tool since the invention of the microscope, with well known resolution limits. Nonlinear optical imaging improves on the resolution limits of linear microscopy, while providing higher contrast images and a greater penetration depth due to the red-shifted incident light compared to standard optical microscopy. It also provides information on molecular orientation and chirality. Adaptive optics can improve the quality of nonlinear optical images. We analyzed the effect of sensorless adaptive optics on the quality of the nonlinear optical images of biological samples. We demonstrate that care needs to be taken when using a large field of view. Our findings provide information on how to improve the quality of nonlinear optical imaging, and can be generalized to other in vitro biological samples. The image quality improvements achieved by adaptive optics should help speed up clinical diagnostics in vitro, while increasing their accuracy and helping decrease detection limits. The same principles apply to in vivo biological samples, and in the future it may be possible to extend these findings to other nonlinear optical effects used in biological imaging.

  13. Quantitative analysis with advanced compensated polarized light microscopy on wavelength dependence of linear birefringence of single crystals causing arthritis

    NASA Astrophysics Data System (ADS)

    Takanabe, Akifumi; Tanaka, Masahito; Taniguchi, Atsuo; Yamanaka, Hisashi; Asahi, Toru

    2014-07-01

    To improve our ability to identify single crystals causing arthritis, we have developed a practical measurement system of polarized light microscopy called advanced compensated polarized light microscopy (A-CPLM). The A-CPLM system is constructed by employing a conventional phase retardation plate, an optical fibre and a charge-coupled device spectrometer in a polarized light microscope. We applied the A-CPLM system to measure linear birefringence (LB) in the visible region, which is an optical anisotropic property, for tiny single crystals causing arthritis, i.e. monosodium urate monohydrate (MSUM) and calcium pyrophosphate dihydrate (CPPD). The A-CPLM system performance was evaluated by comparing the obtained experimental data using the A-CPLM system with (i) literature data for a standard sample, MgF2, and (ii) experimental data obtained using an established optical method, high-accuracy universal polarimeter, for the MSUM. The A-CPLM system was found to be applicable for measuring the LB spectra of the single crystals of MSUM and CPPD, which cause arthritis, in the visible regions. We quantitatively reveal the large difference in LB between MSUM and CPPD crystals. These results demonstrate the usefulness of the A-CPLM system for distinguishing the crystals causing arthritis.

  14. Speckle-based volume holographic microscopy for optically sectioned multi-plane fluorescent imaging.

    PubMed

    Chen, Hsi-Hsun; Singh, Vijay Raj; Luo, Yuan

    2015-03-23

    Structured illumination microscopy has been widely used to reconstruct optically sectioned fluorescence images in wide-field fashion; however, it still requires axial scanning to obtain multiple depth information of a volumetric sample. In this paper, a new imaging scheme, called speckle-based volume holographic microscopy system, is presented. The proposed system incorporates volumetric speckle illumination and multiplexed volume holographic gratings to acquire multi-plane images with optical sectioning capability, without any axial scanning. We present the design, implementation, and experimental image data demonstrating the proposed system's ability to simultaneously obtain wide-field, optically sectioned, and multi-depth resolved images of fluorescently labeled microspheres and tissue structures.

  15. Generalized model for incoherent detection in confocal optical microscopy.

    PubMed

    Hammoum, Rachid; Hamady, Sidi Ould Saad; Fontana, Marc D

    2010-06-01

    We develop a generalized model in order to calculate the point spread functions in both the focal and the detection planes for the electric field strengths. In these calculations, based on the generalized Jones matrices, we introduce all of the interdependent parameters that could influence the spatial resolution of a confocal optical microscope. Our proposed model is more nearly complete, since we make no approximations of the scattered electric fields. These results can be successfully applied to standard confocal optical techniques to get a better understanding for more quantitative interpretations of the probe.

  16. Accurate cell counts in live mouse embryos using optical quadrature and differential interference contrast microscopy

    NASA Astrophysics Data System (ADS)

    Warger, William C., II; Newmark, Judith A.; Zhao, Bing; Warner, Carol M.; DiMarzio, Charles A.

    2006-02-01

    Present imaging techniques used in in vitro fertilization (IVF) clinics are unable to produce accurate cell counts in developing embryos past the eight-cell stage. We have developed a method that has produced accurate cell counts in live mouse embryos ranging from 13-25 cells by combining Differential Interference Contrast (DIC) and Optical Quadrature Microscopy. Optical Quadrature Microscopy is an interferometric imaging modality that measures the amplitude and phase of the signal beam that travels through the embryo. The phase is transformed into an image of optical path length difference, which is used to determine the maximum optical path length deviation of a single cell. DIC microscopy gives distinct cell boundaries for cells within the focal plane when other cells do not lie in the path to the objective. Fitting an ellipse to the boundary of a single cell in the DIC image and combining it with the maximum optical path length deviation of a single cell creates an ellipsoidal model cell of optical path length deviation. Subtracting the model cell from the Optical Quadrature image will either show the optical path length deviation of the culture medium or reveal another cell underneath. Once all the boundaries are used in the DIC image, the subtracted Optical Quadrature image is analyzed to determine the cell boundaries of the remaining cells. The final cell count is produced when no more cells can be subtracted. We have produced exact cell counts on 5 samples, which have been validated by Epi-Fluorescence images of Hoechst stained nuclei.

  17. A fiber-optic system for dual-modality photoacoustic microscopy and confocal fluorescence microscopy using miniature components☆

    PubMed Central

    Chen, Sung-Liang; Xie, Zhixing; Guo, L. Jay; Wang, Xueding

    2013-01-01

    Imaging of the cells and microvasculature simultaneously is beneficial to the study of tumor angiogenesis and microenvironments. We designed and built a fiber-optic based photoacoustic microscopy (PAM) and confocal fluorescence microscopy (CFM) dual-modality imaging system. To explore the feasibility of this all-optical device for future endoscopic applications, a microelectromechanical systems (MEMS) scanner, a miniature objective lens, and a small size optical microring resonator as an acoustic detector were employed trying to meet the requirements of miniaturization. Both the lateral resolutions of PAM and CFM were quantified to be 8.8 μm. Axial resolutions of PAM and CFM were experimentally measured to be 19 μm and 53 μm, respectively. The experiments on ex vivo animal bladder tissues demonstrate the good performance of this system in imaging not only microvasculature but also cellular structure, suggesting that this novel imaging technique holds potential for improved diagnosis and guided treatment of bladder cancer. PMID:24466507

  18. Removing lateral chromatic aberration in bright field optical microscopy.

    PubMed

    Guzmán-Altamirano, Miguel; Gutiérrez-Medina, Braulio

    2015-06-01

    We present an efficient alternative to remove lateral chromatic aberration (LCA) in bright field light microscopy images. Our procedure is based on error calibration using time-sequential acquisition at different wavelengths, and error correction through digital image warping. Measurement of the displacements of fiducial marks in the red and green images relative to blue provide calibration factors that are subsequently used in test images to realign color channels digitally. We demonstrate quantitative improvement in the position and boundaries of objects in target slides and in the color content and morphology of specimens in stained biological samples. Our results show a reduction of LCA content below the 0.1% level.

  19. Single crystal optic elements for helium atom microscopy

    NASA Astrophysics Data System (ADS)

    MacLaren, D. A.; Allison, W.; Holst, B.

    2000-07-01

    Focusing characteristics of asymmetrically bent single crystal mirrors are discussed in the context of fabricating an optic element for an helium atom microscope. We demonstrate the principle that deforming a clamped, elliptical, single crystal under electrostatic pressure can produce submicron focusing of an helium beam. We present a systematic procedure that may be used to fabricate high precision mirrors close to the Cartesian ideal of any chosen optical configuration. In particular, imaging systems with asymmetric mirror profiles are discussed. Results are independent of crystal characteristics and can be adapted to fit a range of experimental geometries. The calculations indicate that mirror-induced aberrations can be eliminated to fourth order by use of a single actuation electrode in an ideal system.

  20. Precision 3-D microscopy with intensity modulated fibre optic scanners

    NASA Astrophysics Data System (ADS)

    Olmos, P.

    2016-01-01

    Optical 3-D imagers constitute a family of precision and useful instruments, easily available on the market in a wide variety of configurations and performances. However, besides their cost they usually provide an image of the object (i.e. a more or less faithful representation of the reality) instead of a truly object's reconstruction. Depending on the detailed working principles of the equipment, this reconstruction may become a challenging task. Here a very simple yet reliable device is described; it is able to form images of opaque objects by illuminating them with an optical fibre and collecting the reflected light with another fibre. Its 3-D capability comes from the spatial filtering imposed by the fibres together with their movement (scanning) along the three directions: transversal (surface) and vertical. This unsophisticated approach allows one to model accurately the entire optical process and to perform the desired reconstruction, finding that information about the surface which is of interest: its profile and its reflectance, ultimately related to the type of material.

  1. Optical Microscopy Techniques to Inspect for Metallic Whiskers

    NASA Technical Reports Server (NTRS)

    Brusse, Jay A.

    2006-01-01

    Metal surface finishes of tin, zinc and cadmium are often applied to electronic components, mechanical hardware and other structures. These finishes sometimes unpredictably may form metal whiskers over periods that can take from hours to months or even many years. The metal whiskers are crystalline structures commonly having uniform cross sectional area along their entire length. Typical whisker dimensions are nominally on the order of only a few microns (um) across while their lengths can extend from a few microns to several millimeters. Metal whiskers pose a reliability hazard to electronic systems primarily as an electrical shorting hazard. The extremely narrow dimensions of metal whiskers can make observation with optical techniques very challenging. The videos herein were compiled to demonstrate the complexities associated with optical microscope inspection of electronic and mechanical components and assemblies for the presence or absence of metal whiskers. The importance of magnification, light source and angle of illumination play critical roles in being able to detect metal whiskers when present. Furthermore, it is demonstrated how improper techniques can easily obscure detection. It is hoped that these videos will improve the probability of detecting metal whiskers with optical inspection techniques.

  2. Optical far-field super-resolution microscopy using nitrogen vacancy center ensemble in bulk diamond

    NASA Astrophysics Data System (ADS)

    Li, Shen; Chen, Xiang-dong; Zhao, Bo-Wen; Dong, Yang; Zou, Chong-Wen; Guo, Guang-Can; Sun, Fang-Wen

    2016-09-01

    We demonstrate optical far-field super-resolution microscopy using an array of nitrogen vacancy centers in bulk diamond as near-field optical probes. The local optical field, which transmits through the nanostructures on the diamond surface, is measured by detecting the charge state conversion of the nitrogen vacancy center. Locating the nitrogen vacancy center with a spatial resolution of 6.1 nm is realized with charge state depletion nanoscopy. The nanostructures on the surface of a diamond are then imaged with a resolution below the optical diffraction limit. The results offer an approach to build a general-purpose optical super-resolution microscopy technique and a convenient platform for high spatial resolution quantum sensing with nitrogen vacancy centers.

  3. Resolving the Pinning Force of Nanobubbles with Optical Microscopy

    NASA Astrophysics Data System (ADS)

    Tan, Beng Hau; An, Hongjie; Ohl, Claus-Dieter

    2017-02-01

    Many of the remarkable properties of surface nanobubbles, such as unusually small contact angles and long lifetimes, are related to the force that pins them onto their substrates. This pinning force is yet to be quantified experimentally. Here, surface-attached nanobubbles are pulled with an atomic force microscope tip while their mechanical responses are observed with total internal reflection fluorescence microscopy. We estimate that a pinning force on the order of 0.1 μ N is required to unpin a nanobubble from its substrate. The maximum force that the tip can exert on the nanobubble is limited by the stability of the neck pulled from the bubble and is enhanced by the hydrophobicity of the tip.

  4. Digital micro-mirror devices in digital optical microscopy

    NASA Astrophysics Data System (ADS)

    Adeyemi, Adekunle Adesanya

    In this thesis, studies on the applications of digital micro-mirror devices (DMD) to enhancement of digital optical microscope images are presented. This involves adaptation of the fast switching capability and high optical efficiency of DMD to control the spatial illumination of the specimen. The first study focuses on a method of using DMD to enhance the dynamic range of a digital optical microscope. Our adaptive feedback illumination control method generates a high dynamic range image through an algorithm that combines the DMD-to-camera pixel geometrical mapping and a feedback operation. The feedback process automatically generates an illumination pattern in an iterative fashion that spatially modulates the DMD array elements on a pixel-by-pixel level. Via experiment, we demonstrate a transmitted-light microscope system that uses precise DMD control of a DMD-based projector to enhance the dynamic range ideally by a factor of 573. Results are presented showing approximately 5 times the camera dynamic range, enabling visualization over a wide range of specimen characteristics. The second study presents a technique for programming the source of the spherical reference illumination in a digital in-line holographic microscope using DMD. The programmable point source is achieved by individually addressing the elements of a DMD to spatially control the illumination of the object located at some distance from the source of the spherical reference field. Translation of the ON-state DMD mirror element changes the spatial location of the point source and consequently generates a sequence of translated holograms of the object. The experimental results obtained through numerical reconstruction of translated holograms of Latex microspheres shows the possibility of expanding the field of view by about 263% and also extracting depth information between features in an object volume. The common challenges associated with the use of DMD in coherent and broadband illumination

  5. Optical ptychographic microscopy for quantitative anisotropic phase imaging

    NASA Astrophysics Data System (ADS)

    Anthony, N.; Cadenazzi, G.; Nugent, K. A.; Abbey, B.

    2016-12-01

    Ptychography has recently been adapted for the recovery of the complete Jones matrix of an anisotropic specimen, using a vectorial form of the Ptychographic Iterative Engine (vPIE) for a set of linearly polarized probes. Here we show that this method can be applied to the recovery of the in-plane components of the elastic strain tensor in a diametrically compressed disc. The advantages and disadvantages of vPIE for the recovery of strain information from `real-world' samples is discussed as well as the potential for this approach to be applied to the characterization of the mechanical properties of optically transparent materials

  6. Time-domain optical coherence tomography with digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Massatsch, Pia; Charrière, Florian; Cuche, Etienne; Marquet, Pierre; Depeursinge, Christian D.

    2005-04-01

    We show that digital holography can be combined easily with optical coherence tomography approach. Varying the reference path length is the means used to acquire a series of holograms at different depths, providing after reconstruction images of slices at different depths in the specimen thanks to the short-coherence length of light source. A metallic object, covered by a 150-µm-thick onion cell, is imaged with high resolution. Applications in ophthalmology are shown: structures of the anterior eye, the cornea, and the iris, are studied on enucleated porcine eyes. Tomographic images of the iris border close to the pupil were obtained 165 µm underneath the eye surface.

  7. X-ray microscopy using grazing-incidence reflections optics

    SciTech Connect

    Price, R.H.

    1983-06-30

    The role of Kirkpatrick-Baez microscopes as the workhorse of the x-ray imaging devices is discussed. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics.

  8. X-ray microscopy using grazing-incidence reflection optics

    SciTech Connect

    Price, R.H.

    1981-08-06

    The Kirkpatrick-Baez microscopes are described along with their role as the workhorse of the x-ray imaging devices. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics.

  9. Digital polarization holography advancing geometrical phase optics.

    PubMed

    De Sio, Luciano; Roberts, David E; Liao, Zhi; Nersisyan, Sarik; Uskova, Olena; Wickboldt, Lloyd; Tabiryan, Nelson; Steeves, Diane M; Kimball, Brian R

    2016-08-08

    Geometrical phase or the fourth generation (4G) optics enables realization of optical components (lenses, prisms, gratings, spiral phase plates, etc.) by patterning the optical axis orientation in the plane of thin anisotropic films. Such components exhibit near 100% diffraction efficiency over a broadband of wavelengths. The films are obtained by coating liquid crystalline (LC) materials over substrates with patterned alignment conditions. Photo-anisotropic materials are used for producing desired alignment conditions at the substrate surface. We present and discuss here an opportunity of producing the widest variety of "free-form" 4G optical components with arbitrary spatial patterns of the optical anisotropy axis orientation with the aid of a digital spatial light polarization converter (DSLPC). The DSLPC is based on a reflective, high resolution spatial light modulator (SLM) combined with an "ad hoc" optical setup. The most attractive feature of the use of a DSLPC for photoalignment of nanometer thin photo-anisotropic coatings is that the orientation of the alignment layer, and therefore of the fabricated LC or LC polymer (LCP) components can be specified on a pixel-by-pixel basis with high spatial resolution. By varying the optical magnification or de-magnification the spatial resolution of the photoaligned layer can be adjusted to an optimum for each application. With a simple "click" it is possible to record different optical components as well as arbitrary patterns ranging from lenses to invisible labels and other transparent labels that reveal different images depending on the side from which they are viewed.

  10. Combining microscopy with mesoscopy using optical and optoacoustic label-free modes

    NASA Astrophysics Data System (ADS)

    Soliman, Dominik; Tserevelakis, George J.; Omar, Murad; Ntziachristos, Vasilis

    2015-08-01

    Biology requires observations at multiple geometrical scales, a feature that is not typically offered by a single imaging modality. We developed a hybrid optical system that not only provides different contrast modes but also offers imaging at different geometrical scales, achieving uniquely broad resolution and a 1000-fold volume sampling increase compared to volumes scanned by optical microscopy. The system combines optoacoustic mesoscopy, optoacoustic microscopy and two-photon microscopy, the latter integrating second and third harmonic generation modes. Label-free imaging of a mouse ear and zebrafish larva ex-vivo demonstrates the contrast and scale complementarity provided by the hybrid system. We showcase the superior anatomical orientation offered by the label-free capacity and hybrid operation, over fluorescence microscopy, and the dynamic selection between field of view and resolution achieved, leading to new possibilities in biological visualization.

  11. Optical protocols for advanced spacecraft networks

    NASA Technical Reports Server (NTRS)

    Bergman, Larry A.

    1991-01-01

    Most present day fiber optic networks are in fact extensions of copper wire networks. As a result, their speed is still limited by electronics even though optics is capable of running three orders of magnitude faster. Also, the fact that photons do not interact with one another (as electrons do) provides optical communication systems with some unique properties or new functionality that is not readily taken advantage of with conventional approaches. Some of the motivation for implementing network protocols in the optical domain, a few possible approaches including optical code-division multiple-access (CDMA), and how this class of networks can extend the technology life cycle of the Space Station Freedom (SSF) with increased performance and functionality are described.

  12. Advances in telecom and datacom optical components

    NASA Astrophysics Data System (ADS)

    Eldada, Louay A.

    2001-07-01

    We review and contrast key technologies developed to address the optical components market for telecom and datacom applications. We first look at different material systems, compare their properties, and describe the functions achieved to date in each of them. The material systems reviewed include glass fiber, silica on silicon, silicon on insulator, silicon oxynitride, sol-gels, polymers, thin film dielectrics, lithium niobate, indium phosphide, gallium arsenide, magneto-optic materials, and birefringent crystals. We then look at the most commonly used classes of technology and present their pros and cons as well as the functions achieved to date in each. The technologies reviewed include passive, actuation, and active technologies. The passive technologies described include fused fibers, dispersion-compensating fiber, beam steering (e.g., AWG), Bragg gratings, diffraction gratings, holographic elements, thin film filters, photonic crystals, microrings, and birefringent elements. The actuation technologies include thermo-optics, electro-optics, acousto- optics, magneto-optics, liquid crystals, total internal reflection technologies (e.g., bubble technology), and mechanical actuation (e.g., moving fibers and MEMS). We finally describe active technologies including heterostructures, quantum wells, rare earth doping, and semiconductor optical amplifiers. We also investigate the use of different material systems and technologies to achieve building block functions including lasers, amplifiers, detectors, modulators, polarization controllers, couplers, filters, switches, attenuators, nonreciprocal elements (Faraday rotators or nonreciprocal phase shifters) for isolators and circulators, wavelength converters, and dispersion compensators.

  13. Visualization of neuritic plaques in Alzheimer’s disease by polarization-sensitive optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Baumann, Bernhard; Woehrer, Adelheid; Ricken, Gerda; Augustin, Marco; Mitter, Christian; Pircher, Michael; Kovacs, Gabor G.; Hitzenberger, Christoph K.

    2017-03-01

    One major hallmark of Alzheimer’s disease (AD) and cerebral amyloid angiopathy (CAA) is the deposition of extracellular senile plaques and vessel wall deposits composed of amyloid-beta (Aβ). In AD, degeneration of neurons is preceded by the formation of Aβ plaques, which show different morphological forms. Most of them are birefringent owing to the parallel arrangement of amyloid fibrils. Here, we present polarization sensitive optical coherence microscopy (PS-OCM) for imaging mature neuritic Aβ plaques based on their birefringent properties. Formalin-fixed, post-mortem brain samples of advanced stage AD patients were investigated. In several cortical brain regions, neuritic Aβ plaques were successfully visualized in tomographic and three-dimensional (3D) images. Cortical grey matter appeared polarization preserving, whereas neuritic plaques caused increased phase retardation. Consistent with the results from PS-OCM imaging, the 3D structure of senile Aβ plaques was computationally modelled for different illumination settings and plaque sizes. Furthermore, the birefringent properties of cortical and meningeal vessel walls in CAA were investigated in selected samples. Significantly increased birefringence was found in smaller vessels. Overall, these results provide evidence that PS-OCM is able to assess amyloidosis based on intrinsic birefringent properties.

  14. Visualization of neuritic plaques in Alzheimer’s disease by polarization-sensitive optical coherence microscopy

    PubMed Central

    Baumann, Bernhard; Woehrer, Adelheid; Ricken, Gerda; Augustin, Marco; Mitter, Christian; Pircher, Michael; Kovacs, Gabor G.; Hitzenberger, Christoph K.

    2017-01-01

    One major hallmark of Alzheimer’s disease (AD) and cerebral amyloid angiopathy (CAA) is the deposition of extracellular senile plaques and vessel wall deposits composed of amyloid-beta (Aβ). In AD, degeneration of neurons is preceded by the formation of Aβ plaques, which show different morphological forms. Most of them are birefringent owing to the parallel arrangement of amyloid fibrils. Here, we present polarization sensitive optical coherence microscopy (PS-OCM) for imaging mature neuritic Aβ plaques based on their birefringent properties. Formalin-fixed, post-mortem brain samples of advanced stage AD patients were investigated. In several cortical brain regions, neuritic Aβ plaques were successfully visualized in tomographic and three-dimensional (3D) images. Cortical grey matter appeared polarization preserving, whereas neuritic plaques caused increased phase retardation. Consistent with the results from PS-OCM imaging, the 3D structure of senile Aβ plaques was computationally modelled for different illumination settings and plaque sizes. Furthermore, the birefringent properties of cortical and meningeal vessel walls in CAA were investigated in selected samples. Significantly increased birefringence was found in smaller vessels. Overall, these results provide evidence that PS-OCM is able to assess amyloidosis based on intrinsic birefringent properties. PMID:28262719

  15. Dynamics of solid lubrication as observed by optical microscopy

    NASA Technical Reports Server (NTRS)

    Sliney, H. E.

    1976-01-01

    A bench metallograph was converted into a micro contact imager by the addition of a tribometer employing a steel ball in sliding contact with a glass disk. The sliding contact was viewed in real time by means of projection microscope optics. The dynamics of abrasive particles and of solid lubricant particles within the contact were observed in detail. The contact was characterized by a constantly changing pattern of elastic strain with the passage of surface discontinuities and solid particles. Abrasive particles fragmented upon entering the contact, embedded in one surface and scratched the other; in contrast, the solid lubricant particles flowed plastically into thin films. The rheological behavior of the lubricating solids gave every appearance of a paste-like consistency within the Hertzian contact.

  16. Nonlinear optical microscopy and ultrasound imaging of human cervical structure

    NASA Astrophysics Data System (ADS)

    Reusch, Lisa M.; Feltovich, Helen; Carlson, Lindsey C.; Hall, Gunnsteinn; Campagnola, Paul J.; Eliceiri, Kevin W.; Hall, Timothy J.

    2013-03-01

    The cervix softens and shortens as its collagen microstructure rearranges in preparation for birth, but premature change may lead to premature birth. The global preterm birth rate has not decreased despite decades of research, likely because cervical microstructure is poorly understood. Our group has developed a multilevel approach to evaluating the human cervix. We are developing quantitative ultrasound (QUS) techniques for noninvasive interrogation of cervical microstructure and corroborating those results with high-resolution images of microstructure from second harmonic generation imaging (SHG) microscopy. We obtain ultrasound measurements from hysterectomy specimens, prepare the tissue for SHG, and stitch together several hundred images to create a comprehensive view of large areas of cervix. The images are analyzed for collagen orientation and alignment with curvelet transform, and registered with QUS data, facilitating multiscale analysis in which the micron-scale SHG images and millimeter-scale ultrasound data interpretation inform each other. This novel combination of modalities allows comprehensive characterization of cervical microstructure in high resolution. Through a detailed comparative study, we demonstrate that SHG imaging both corroborates the quantitative ultrasound measurements and provides further insight. Ultimately, a comprehensive understanding of specific microstructural cervical change in pregnancy should lead to novel approaches to the prevention of preterm birth.

  17. Nonlinear optical microscopy and ultrasound imaging of human cervical structure

    PubMed Central

    Reusch, Lisa M.; Feltovich, Helen; Carlson, Lindsey C.; Hall, Gunnsteinn; Campagnola, Paul J.; Eliceiri, Kevin W.

    2013-01-01

    Abstract. The cervix softens and shortens as its collagen microstructure rearranges in preparation for birth, but premature change may lead to premature birth. The global preterm birth rate has not decreased despite decades of research, likely because cervical microstructure is poorly understood. Our group has developed a multilevel approach to evaluating the human cervix. We are developing quantitative ultrasound (QUS) techniques for noninvasive interrogation of cervical microstructure and corroborating those results with high-resolution images of microstructure from second harmonic generation imaging (SHG) microscopy. We obtain ultrasound measurements from hysterectomy specimens, prepare the tissue for SHG, and stitch together several hundred images to create a comprehensive view of large areas of cervix. The images are analyzed for collagen orientation and alignment with curvelet transform, and registered with QUS data, facilitating multiscale analysis in which the micron-scale SHG images and millimeter-scale ultrasound data interpretation inform each other. This novel combination of modalities allows comprehensive characterization of cervical microstructure in high resolution. Through a detailed comparative study, we demonstrate that SHG imaging both corroborates the quantitative ultrasound measurements and provides further insight. Ultimately, a comprehensive understanding of specific microstructural cervical change in pregnancy should lead to novel approaches to the prevention of preterm birth. PMID:23412434

  18. Integrated acoustic-resolution and optical-resolution photoacoustic microscopy using a single multifunctional acoustic lens

    NASA Astrophysics Data System (ADS)

    Guo, Heng; Xi, Lei

    2016-10-01

    With the rapid development of photoacoustic imaging, it has been widely used in various research fields such as biology, medicine and nanotechnology. Due to the huge difference among photoacoustic imaging systems, it is hard to integrate them in one platform. To solve this problem, we propose to develop a new universal photoacoustic imaging platform that integrates acoustic-resolution photoacoustic microscopy and optical-resolution photoacoustic microscopy through a multifunctional liquid lens. This lens takes advantage of an inherently low acoustic impedance and a tunable focal length that was characterized by the infusion volume of the liquid. In this paper, the liquid lens was used to realize confocal of laser illumination and acoustic detection for both acoustic-resolution and optical-resolution photoacoustic microscopy. The home-made polyvinylidene fluoride (PVDF) acoustic transducer had a center frequency of 10MHz and -6dB frequency spectrum from 4MHz to 15MHz which yielded to an axial resolution of 70 μm. The lateral resolutions of acoustic- and optical-resolution photoacoustic microscopy were evaluated to be 180 μm and 4.8 μm, respectively. The vasculature of rat ears was carried out to evaluate the performance of optical-resolution photoacoustic microscopy.

  19. Axial range of conjugate adaptive optics in two-photon microscopy.

    PubMed

    Paudel, Hari P; Taranto, John; Mertz, Jerome; Bifano, Thomas

    2015-08-10

    We describe an adaptive optics technique for two-photon microscopy in which the deformable mirror used for aberration compensation is positioned in a plane conjugate to the plane of the aberration. We demonstrate in a proof-of-principle experiment that this technique yields a large field of view advantage in comparison to standard pupil-conjugate adaptive optics. Further, we show that the extended field of view in conjugate AO is maintained over a relatively large axial translation of the deformable mirror with respect to the conjugate plane. We conclude with a discussion of limitations and prospects for the conjugate AO technique in two-photon biological microscopy.

  20. Optical Microscopy Characterization for Borehole U-15n#12 in Support of NCNS Source Physics Experiment

    SciTech Connect

    Wilson, Jennifer E.; Sussman, Aviva Joy

    2015-05-22

    Optical microscopy characterization of thin sections from corehole U-15n#12 is part of a larger material characterization effort for the Source Physics Experiment (SPE). The SPE program was conducted in Nevada with a series of explosive tests designed to study the generation and propagation of seismic waves inside Stock quartz monzonite. Optical microscopy analysis includes the following: 1) imaging of full thin sections (scans and mosaic maps); 2) high magnification imaging of petrographic texture (grain size, foliations, fractures, etc.); and 3) measurement of microfracture density.

  1. Super-resolution optical microscopy based on scannable cantilever-combined microsphere.

    PubMed

    Wang, Shuying; Zhang, Dongxian; Zhang, Haijun; Han, Xu; Xu, Rui

    2015-12-01

    We report an ingenious method of super-resolution optical microscopy utilizing scannable cantilever-combined microsphere. By scanning the microsphere over the sample surface in a cantilever-combined microsphere-sample contact state, super-resolution images can be acquired at arbitrary sample regions through near-field information collection by the microsphere. In addition, such a state can effectively reduce the possibility of breaking the cantilever and damaging the microsphere or sample surface. This work has developed a new method and technique of sub-diffraction-limit optical microscopy, and can be practically applied in various fields of micro/nanoscopy.

  2. Follow-up review: recent progress in the development of super-resolution optical microscopy.

    PubMed

    Fujita, Katsumasa

    2016-08-01

    The advent of super-resolution microscopy brought a huge impact to various research fields ranging from the fundamental science to medical and industrial applications. The technological development is still ongoing with involving different scientific disciplines and often changing the standard of optical imaging. In this review, I would like to introduce the recent research progress in super-resolution microscopy as a follow-up for the featured issue in Microscopy (Vol. 64, No. 4, 2015) with discussions especially on the current trends and new directions in the technological development.

  3. Analysis of advanced optical glass and systems

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry; Feng, Chen

    1991-01-01

    Optical lens systems performance utilizing optical materials comprising reluctant glass forming compositions was studied. Such special glasses are being explored by NASA/Marshall Space Flight Center (MSFC) researchers utilizing techniques such as containerless processing in space on the MSFC Acoustic Levitation Furnace and on the High Temperature Acoustic Levitation Furnace in the conceptual design phase for the United States Microgravity Laboratory (USML) series of shuttle flights. The application of high refractive index and low dispersive power glasses in optical lens design was investigated. The potential benefits and the impacts to the optical lens design performance were evaluated. The results of the studies revealed that the use of these extraordinary glasses can result in significant optical performance improvements. Recommendations of proposed optical properties for potential new glasses were also made. Applications of these new glasses are discussed, including the impact of high refractive index and low dispersive power, improvements of the system performance by using glasses which are located outside of traditional glass map, and considerations in establishing glass properties beyond conventional glass map limits.

  4. Transparent thin-film characterization by using differential optical sectioning interference microscopy.

    PubMed

    Wang, Chun-Chieh; Lin, Jiunn-Yuan; Jian, Hung-Jhang; Lee, Chau-Hwang

    2007-10-20

    We propose an optical thin-film characterization technique, differential optical sectioning interference microscopy (DOSIM), for simultaneously measuring the refractive indices and thicknesses of transparent thin films with submicrometer lateral resolution. DOSIM obtains the depth and optical phase information of a thin film by using a dual-scan concept in differential optical sectioning microscopy combined with the Fabry-Perot interferometric effect and allows the solution of refractive index and thickness without the 2pi phase-wrapping ambiguity. Because DOSIM uses a microscope objective as the probe, its lateral resolution achieves the diffraction limit. As a demonstration, we measure the refractive indices and thicknesses of SiO2 thin films grown on Si substrate and indium-tin-oxide thin films grown on a glass substrate. We also compare the measurement results of DOSIM with those of a conventional ellipsometer and an atomic force microscope.

  5. Chip-based optical microscopy for imaging membrane sieve plates of liver scavenger cells

    NASA Astrophysics Data System (ADS)

    Helle, Øystein I.; Øie, Cristina I.; McCourt, Peter; Ahluwalia, Balpreet S.

    2015-08-01

    The evanescent field on top of optical waveguides is used to image membrane network and sieve-plates of liver endothelial cells. In waveguide excitation, the evanescent field is dominant only near the surface (~100-150 nm) providing a default optical sectioning by illuminating fluorophores in close proximity to the surface and thus benefiting higher signal-to-noise ratio. The sieve plates of liver sinusoidal endothelial cells are present on the cell membrane, thus near-field waveguide chip-based microscopy configuration is preferred over epi-fluorescence. The waveguide chip is compatible with optical fiber components allowing easy multiplexing to different wavelengths. In this paper, we will discuss the challenges and opportunities provided by integrated optical microscopy for imaging cell membranes.

  6. Ultra-sensitive Magnetic Microscopy with an Optically Pumped Magnetometer

    NASA Astrophysics Data System (ADS)

    Kim, Young Jin; Savukov, Igor

    2016-04-01

    Optically pumped magnetometers (OPMs) based on lasers and alkali-metal vapor cells are currently the most sensitive non-cryogenic magnetic field sensors. Many applications in neuroscience and other fields require high-resolution, high-sensitivity magnetic microscopic measurements. In order to meet this demand we combined a cm-size spin-exchange relaxation-free (SERF) OPM and flux guides (FGs) to realize an ultra-sensitive FG-OPM magnetic microscope. The FGs serve to transmit the target magnetic flux to the OPM thus improving both the resolution and sensitivity to small magnetic objects. We investigated the performance of the FG-OPM device using experimental and numerical methods, and demonstrated that an optimized device can achieve a unique combination of high resolution (80 μm) and high sensitivity (8.1 pT/). In addition, we also performed numerical calculations of the magnetic field distribution in the FGs to estimate the magnetic noise originating from the domain fluctuations in the material of the FGs. We anticipate many applications of the FG-OPM device such as the detection of micro-biological magnetic fields; the detection of magnetic nano-particles; and non-destructive testing. From our theoretical estimate, an FG-OPM could detect the magnetic field of a single neuron, which would be an important milestone in neuroscience.

  7. Ultra-sensitive magnetic microscopy with an optically pumped magnetometer

    SciTech Connect

    Kim, Young Jin; Savukov, Igor Mykhaylovich

    2016-04-22

    Optically pumped magnetometers (OPMs) based on lasers and alkali-metal vapor cells are currently the most sensitive non-cryogenic magnetic field sensors. Many applications in neuroscience and other fields require high-resolution, high-sensitivity magnetic microscopic measurements. In order to meet this demand we combined a cm-size spin-exchange relaxation-free (SERF) OPM and flux guides (FGs) to realize an ultra-sensitive FG-OPM magnetic microscope. The FGs serve to transmit the target magnetic flux to the OPM thus improving both the resolution and sensitivity to small magnetic objects. We investigated the performance of the FG-OPM device using experimental and numerical methods, and demonstrated that an optimized device can achieve a unique combination of high resolution (80 μm) and high sensitivity (8.1 pT/). Additionally, we also performed numerical calculations of the magnetic field distribution in the FGs to estimate the magnetic noise originating from the domain fluctuations in the material of the FGs. We anticipate many applications of the FG-OPM device such as the detection of micro-biological magnetic fields; the detection of magnetic nano-particles; and non-destructive testing. From our theoretical estimate, an FG-OPM could detect the magnetic field of a single neuron, which would be an important milestone in neuroscience.

  8. Ultra-sensitive magnetic microscopy with an optically pumped magnetometer

    DOE PAGES

    Kim, Young Jin; Savukov, Igor Mykhaylovich

    2016-04-22

    Optically pumped magnetometers (OPMs) based on lasers and alkali-metal vapor cells are currently the most sensitive non-cryogenic magnetic field sensors. Many applications in neuroscience and other fields require high-resolution, high-sensitivity magnetic microscopic measurements. In order to meet this demand we combined a cm-size spin-exchange relaxation-free (SERF) OPM and flux guides (FGs) to realize an ultra-sensitive FG-OPM magnetic microscope. The FGs serve to transmit the target magnetic flux to the OPM thus improving both the resolution and sensitivity to small magnetic objects. We investigated the performance of the FG-OPM device using experimental and numerical methods, and demonstrated that an optimized devicemore » can achieve a unique combination of high resolution (80 μm) and high sensitivity (8.1 pT/). Additionally, we also performed numerical calculations of the magnetic field distribution in the FGs to estimate the magnetic noise originating from the domain fluctuations in the material of the FGs. We anticipate many applications of the FG-OPM device such as the detection of micro-biological magnetic fields; the detection of magnetic nano-particles; and non-destructive testing. From our theoretical estimate, an FG-OPM could detect the magnetic field of a single neuron, which would be an important milestone in neuroscience.« less

  9. Ultra-sensitive Magnetic Microscopy with an Optically Pumped Magnetometer.

    PubMed

    Kim, Young Jin; Savukov, Igor

    2016-04-22

    Optically pumped magnetometers (OPMs) based on lasers and alkali-metal vapor cells are currently the most sensitive non-cryogenic magnetic field sensors. Many applications in neuroscience and other fields require high-resolution, high-sensitivity magnetic microscopic measurements. In order to meet this demand we combined a cm-size spin-exchange relaxation-free (SERF) OPM and flux guides (FGs) to realize an ultra-sensitive FG-OPM magnetic microscope. The FGs serve to transmit the target magnetic flux to the OPM thus improving both the resolution and sensitivity to small magnetic objects. We investigated the performance of the FG-OPM device using experimental and numerical methods, and demonstrated that an optimized device can achieve a unique combination of high resolution (80 μm) and high sensitivity (8.1 pT/). In addition, we also performed numerical calculations of the magnetic field distribution in the FGs to estimate the magnetic noise originating from the domain fluctuations in the material of the FGs. We anticipate many applications of the FG-OPM device such as the detection of micro-biological magnetic fields; the detection of magnetic nano-particles; and non-destructive testing. From our theoretical estimate, an FG-OPM could detect the magnetic field of a single neuron, which would be an important milestone in neuroscience.

  10. Generalized spectral method for near-field optical microscopy

    SciTech Connect

    Jiang, B.-Y.; Zhang, L. M.; Basov, D. N.; Fogler, M. M.; Castro Neto, A. H.

    2016-02-07

    Electromagnetic interaction between a sub-wavelength particle (the “probe”) and a material surface (the “sample”) is studied theoretically. The interaction is shown to be governed by a series of resonances corresponding to surface polariton modes localized near the probe. The resonance parameters depend on the dielectric function and geometry of the probe as well as on the surface reflectivity of the material. Calculation of such resonances is carried out for several types of axisymmetric probes: spherical, spheroidal, and pear-shaped. For spheroids, an efficient numerical method is developed, capable of handling cases of large or strongly momentum-dependent surface reflectivity. Application of the method to highly resonant materials, such as aluminum oxide (by itself or covered with graphene), reveals a rich structure of multi-peak spectra and nonmonotonic approach curves, i.e., the probe-sample distance dependence. These features also strongly depend on the probe shape and optical constants of the model. For less resonant materials such as silicon oxide, the dependence is weak, so that the spheroidal model is reliable. The calculations are done within the quasistatic approximation with radiative damping included perturbatively.

  11. Generalized spectral method for near-field optical microscopy

    NASA Astrophysics Data System (ADS)

    Jiang, B.-Y.; Zhang, L. M.; Castro Neto, A. H.; Basov, D. N.; Fogler, M. M.

    2016-02-01

    Electromagnetic interaction between a sub-wavelength particle (the "probe") and a material surface (the "sample") is studied theoretically. The interaction is shown to be governed by a series of resonances corresponding to surface polariton modes localized near the probe. The resonance parameters depend on the dielectric function and geometry of the probe as well as on the surface reflectivity of the material. Calculation of such resonances is carried out for several types of axisymmetric probes: spherical, spheroidal, and pear-shaped. For spheroids, an efficient numerical method is developed, capable of handling cases of large or strongly momentum-dependent surface reflectivity. Application of the method to highly resonant materials, such as aluminum oxide (by itself or covered with graphene), reveals a rich structure of multi-peak spectra and nonmonotonic approach curves, i.e., the probe-sample distance dependence. These features also strongly depend on the probe shape and optical constants of the model. For less resonant materials such as silicon oxide, the dependence is weak, so that the spheroidal model is reliable. The calculations are done within the quasistatic approximation with radiative damping included perturbatively.

  12. Ultra-sensitive Magnetic Microscopy with an Optically Pumped Magnetometer

    PubMed Central

    Kim, Young Jin; Savukov, Igor

    2016-01-01

    Optically pumped magnetometers (OPMs) based on lasers and alkali-metal vapor cells are currently the most sensitive non-cryogenic magnetic field sensors. Many applications in neuroscience and other fields require high-resolution, high-sensitivity magnetic microscopic measurements. In order to meet this demand we combined a cm-size spin-exchange relaxation-free (SERF) OPM and flux guides (FGs) to realize an ultra-sensitive FG-OPM magnetic microscope. The FGs serve to transmit the target magnetic flux to the OPM thus improving both the resolution and sensitivity to small magnetic objects. We investigated the performance of the FG-OPM device using experimental and numerical methods, and demonstrated that an optimized device can achieve a unique combination of high resolution (80 μm) and high sensitivity (8.1 pT/). In addition, we also performed numerical calculations of the magnetic field distribution in the FGs to estimate the magnetic noise originating from the domain fluctuations in the material of the FGs. We anticipate many applications of the FG-OPM device such as the detection of micro-biological magnetic fields; the detection of magnetic nano-particles; and non-destructive testing. From our theoretical estimate, an FG-OPM could detect the magnetic field of a single neuron, which would be an important milestone in neuroscience. PMID:27103463

  13. Multicolor 3D super-resolution imaging by quantum dot stochastic optical reconstruction microscopy.

    PubMed

    Xu, Jianquan; Tehrani, Kayvan F; Kner, Peter

    2015-03-24

    We demonstrate multicolor three-dimensional super-resolution imaging with quantum dots (QSTORM). By combining quantum dot asynchronous spectral blueing with stochastic optical reconstruction microscopy and adaptive optics, we achieve three-dimensional imaging with 24 nm lateral and 37 nm axial resolution. By pairing two short-pass filters with two appropriate quantum dots, we are able to image single blueing quantum dots on two channels simultaneously, enabling multicolor imaging with high photon counts.

  14. X-ray Laue Diffraction Microscopy in 3D at the Advanced Photon Source

    SciTech Connect

    Liu, W.; Zschack, P.; Tischler, Jonathan Zachary; Ice, Gene E; Larson, Ben C

    2011-01-01

    Studies of materials on mesoscopic length-scales require a penetrating structural probe with submicron point-to-point spatial resolution. The principle research activities at beamline 34-ID-E of the Advanced Photon Source (APS) involve development of exciting new micro-/nano-diffraction techniques for characterization and microscopy in support of both applied engineering and fundamental materials research. Taking advantage of the high brightness of the source, advanced focusing mirrors, a novel depth profiling technique, and high-speed area detectors, three-dimensional scanning Laue diffraction microscopy provides detailed local structural information of crystalline materials, such as crystallographic orientation, orientation gradients, and strain tensors. It is general and applicable to single-crystal, polycrystalline, composite, deformed, and functionally graded materials. Applications include 3D diffraction investigations for a diverse and growing user community with interests in materials deformation, electro-migration, recrystallization, fatigue, solid-solution precipitation, high-pressure environments, and condensed matter physics.

  15. Harmonic demodulation and minimum enhancement factors in field-enhanced near-field optical microscopy.

    PubMed

    Scarpettini, A F; Bragas, A V

    2015-01-01

    Field-enhanced scanning optical microscopy relies on the design and fabrication of plasmonic probes which had to provide optical and chemical contrast at the nanoscale. In order to do so, the scattering containing the near-field information recorded in a field-enhanced scanning optical microscopy experiment, has to surpass the background light, always present due to multiple interferences between the macroscopic probe and sample. In this work, we show that when the probe-sample distance is modulated with very low amplitude, the higher the harmonic demodulation is, the better the ratio between the near-field signal and the interferometric background results. The choice of working at a given n harmonic is dictated by the experiment when the signal at the n + 1 harmonic goes below the experimental noise. We demonstrate that the optical contrast comes from the nth derivative of the near-field scattering, amplified by the interferometric background. By modelling the far and near field we calculate the probe-sample approach curves, which fit very well the experimental ones. After taking a great amount of experimental data for different probes and samples, we conclude with a table of the minimum enhancement factors needed to have optical contrast with field-enhanced scanning optical microscopy.

  16. Advanced silicon device technologies for optical interconnects

    NASA Astrophysics Data System (ADS)

    Wosinski, Lech; Wang, Zhechao; Lou, Fei; Dai, Daoxin; Lourdudoss, Sebastian; Thylen, Lars

    2012-01-01

    Silicon photonics is an emerging technology offering novel solutions in different areas requiring highly integrated communication systems for optical networking, sensing, bio-applications and computer interconnects. Silicon photonicsbased communication has many advantages over electric wires for multiprocessor and multicore macro-chip architectures including high bandwidth data transmission, high speed and low power consumption. Following the INTEL's concept to "siliconize" photonics, silicon device technologies should be able to solve the fabrication problems for six main building blocks for realization of optical interconnects: light generation, guiding of light including wavelength selectivity, light modulation for signal encoding, detection, low cost assembly including optical connecting of the devices to the real world and finally the electronic control systems.

  17. Advanced Imaging Optics Utilizing Wavefront Coding.

    SciTech Connect

    Scrymgeour, David; Boye, Robert; Adelsberger, Kathleen

    2015-06-01

    Image processing offers a potential to simplify an optical system by shifting some of the imaging burden from lenses to the more cost effective electronics. Wavefront coding using a cubic phase plate combined with image processing can extend the system's depth of focus, reducing many of the focus-related aberrations as well as material related chromatic aberrations. However, the optimal design process and physical limitations of wavefront coding systems with respect to first-order optical parameters and noise are not well documented. We examined image quality of simulated and experimental wavefront coded images before and after reconstruction in the presence of noise. Challenges in the implementation of cubic phase in an optical system are discussed. In particular, we found that limitations must be placed on system noise, aperture, field of view and bandwidth to develop a robust wavefront coded system.

  18. Recent advancements in optical microstructure fabrication through glass molding process

    NASA Astrophysics Data System (ADS)

    Zhou, Tianfeng; Liu, Xiaohua; Liang, Zhiqiang; Liu, Yang; Xie, Jiaqing; Wang, Xibin

    2017-02-01

    Optical microstructures are increasingly applied in several fields, such as optical systems, precision measurement, and microfluid chips. Microstructures include microgrooves, microprisms, and microlenses. This paper presents an overview of optical microstructure fabrication through glass molding and highlights the applications of optical microstructures in mold fabrication and glass molding. The glass-mold interface friction and adhesion are also discussed. Moreover, the latest advancements in glass molding technologies are detailed, including new mold materials and their fabrication methods, viscoelastic constitutive modeling of glass, and microstructure molding process, as well as ultrasonic vibrationassisted molding technology.

  19. Micro-optics metrology using advanced interferometry

    NASA Astrophysics Data System (ADS)

    Reichelt, Stephan; Bieber, Alexander; Aatz, Bernd; Zappe, Hans

    2005-06-01

    Interferometric testing of micro-optical components involves some challenges due to problems such as Fresnel diffraction artefacts, the non-common path interferometer configuration, coherent noise as well disturbing interferences, and uncertainties in distance measurements. Recently we have developed a versatile Mach-Zehnder / Twyman-Green hybride interferometer for micro-optics testing. The system combines the advantages of both interferometer types and allows full characterization of lens and surface figure errors as well as radius of curvature and focal length measurements. The interferometer system is explained and measurement results of micro-lenses are presented. Furthermore, this paper is concerned with the metrology challenges of interferometric testing on microscopic scales.

  20. Characterization of X-ray polycapillary optics by LiF crystal radiation detectors through confocal fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Bonfigli, Francesca; Hampai, Dariush; Dabagov, Sultan B.; Montereali, Rosa Maria

    2016-08-01

    Solid-state radiation imaging detectors based on photoluminescent colour centres in lithium fluoride (LiF) crystals have been successfully tested for both advanced 2D and 3D characterizations of X-ray polycapillary optics by a table-top laboratory system. Polycapillary optics can control X-ray beams propagation and allows obtaining quasi-parallel beam (half-lens) or focused beams (full-lens). The combination of a fine-focused micro X-ray tube and a polycapillary lens can provide the high intensity radiation fluxes that are necessary for high resolution X-ray imaging. In this paper we present novel results about advanced characterization of these complex optics by 2D as well as 3D confocal laser fluorescence microscopy of X-ray irradiated LiF crystal detectors. Two dimensional high spatial resolution images on a wide field of view of transmitted X-rays through a semi-lens and 3D direct inspection of the coloured volumes produced in LiF crystals by both focused and parallel X-ray beam transmitted by a full and a semi-lens, respectively, as well as their 3D reconstructions were obtained. The results show that the photoluminescent colour centres volume in LiF crystals combined with an optical sectioning reading system provide information about tomography of transmitted X-ray beams by policapillary optics in a single exposure process. For the first time, the use of LiF crystal plates as versatile radiation imaging luminescent detectors have been used to characterize the operation of polycapillary optics as X-ray lens, in focusing and parallel mode.

  1. Optical heterodyne-detected Raman-Induced Kerr Effect (OHD-RIKE) microscopy

    PubMed Central

    Freudiger, Christian W.; Roeffaers, Maarten B. J.; Zhang, Xu; Saar, Brian G.; Min, X., Wei; Xie, Sunney

    2012-01-01

    Label-free microscopy based on Raman scattering has been increasingly used in biomedical research to image samples that cannot be labeled or stained. Stimulated Raman scattering (SRS) microscopy, allows signal amplification of the weak Raman signal for fast imaging speeds without introducing the non-resonant background and coherent image artifacts that are present in coherent anti-Stokes Raman scattering (CARS) microscopy. Here we present the Raman-induced Kerr effect (RIKE) as a contrast for label-free microscopy. RIKE allows us to measure different elements of the non-linear susceptibility tensor, both the real and imaginary parts by optical heterodyne detection (OHD-RIKE). OHD-RIKE microscopy provides information similar to polarization CARS (P-CARS) and interferometric CARS (I-CARS) microscopy, with a simple modification of the two-beam SRS microscopy setup. We show that while OHD-RIKE micro-spectroscopy can be in principle more sensitive than SRS, it does not supersede SRS microscopy of heterogeneous biological samples, such as mouse skin tissue, because it is complicated by variations of linear birefringence across the sample. PMID:21504149

  2. Modulated-alignment dual-axis (MAD) confocal microscopy for deep optical sectioning in tissues

    PubMed Central

    Leigh, Steven Y.; Chen, Ye; Liu, Jonathan T.C.

    2014-01-01

    A strategy is presented to enable optical-sectioning microscopy with improved contrast and imaging depth using low-power (0.5 - 1 mW) diode laser illumination. This technology combines the inherent strengths of focal-modulation microscopy and dual-axis confocal (DAC) microscopy for rejecting out-of-focus and multiply scattered background light in tissues. The DAC architecture is unique in that it utilizes an intersecting pair of illumination and collection beams to improve the spatial-filtering and optical-sectioning performance of confocal microscopy while focal modulation selectively ‘labels’ in-focus signals via amplitude modulation. Simulations indicate that modulating the spatial alignment of dual-axis beams at a frequency f generates signals from the focal volume of the microscope that are modulated at 2f with minimal modulation of background signals, thus providing nearly an order-of-magnitude improvement in optical-sectioning contrast compared to DAC microscopy alone. Experiments show that 2f lock-in detection enhances contrast and imaging depth within scattering phantoms and fresh tissues. PMID:24940534

  3. Nonlinear optical microscopy for immunoimaging: a custom optimized system of high-speed, large-area, multicolor imaging

    PubMed Central

    Li, Hui; Cui, Quan; Zhang, Zhihong; Luo, Qingming

    2015-01-01

    Background The nonlinear optical microscopy has become the current state-of-the-art for intravital imaging. Due to its advantages of high resolution, superior tissue penetration, lower photodamage and photobleaching, as well as intrinsic z-sectioning ability, this technology has been widely applied in immunoimaging for a decade. However, in terms of monitoring immune events in native physiological environment, the conventional nonlinear optical microscope system has to be optimized for live animal imaging. Generally speaking, three crucial capabilities are desired, including high-speed, large-area and multicolor imaging. Among numerous high-speed scanning mechanisms used in nonlinear optical imaging, polygon scanning is not only linearly but also dispersion-freely with high stability and tunable rotation speed, which can overcome disadvantages of multifocal scanning, resonant scanner and acousto-optical deflector (AOD). However, low frame rate, lacking large-area or multicolor imaging ability make current polygonbased nonlinear optical microscopes unable to meet the requirements of immune event monitoring. Methods We built up a polygon-based nonlinear optical microscope system which was custom optimized for immunoimaging with high-speed, large-are and multicolor imaging abilities. Results Firstly, we validated the imaging performance of the system by standard methods. Then, to demonstrate the ability to monitor immune events, migration of immunocytes observed by the system based on typical immunological models such as lymph node, footpad and dorsal skinfold chamber are shown. Finally, we take an outlook for the possible advance of related technologies such as sample stabilization and optical clearing for more stable and deeper intravital immunoimaging. Conclusions This study will be helpful for optimizing nonlinear optical microscope to obtain more comprehensive and accurate information of immune events. PMID:25694951

  4. Single-molecule force spectroscopy: optical tweezers, magnetic tweezers and atomic force microscopy

    PubMed Central

    Neuman, Keir C.; Nagy, Attila

    2012-01-01

    Single-molecule force spectroscopy has emerged as a powerful tool to investigate the forces and motions associated with biological molecules and enzymatic activity. The most common force spectroscopy techniques are optical tweezers, magnetic tweezers and atomic force microscopy. These techniques are described and illustrated with examples highlighting current capabilities and limitations. PMID:18511917

  5. Single-molecule force spectroscopy: optical tweezers, magnetic tweezers and atomic force microscopy.

    PubMed

    Neuman, Keir C; Nagy, Attila

    2008-06-01

    Single-molecule force spectroscopy has emerged as a powerful tool to investigate the forces and motions associated with biological molecules and enzymatic activity. The most common force spectroscopy techniques are optical tweezers, magnetic tweezers and atomic force microscopy. Here we describe these techniques and illustrate them with examples highlighting current capabilities and limitations.

  6. Fast Calcium Imaging with Optical Sectioning via HiLo Microscopy.

    PubMed

    Lauterbach, Marcel A; Ronzitti, Emiliano; Sternberg, Jenna R; Wyart, Claire; Emiliani, Valentina

    2015-01-01

    Imaging intracellular calcium concentration via reporters that change their fluorescence properties upon binding of calcium, referred to as calcium imaging, has revolutionized our way to probe neuronal activity non-invasively. To reach neurons densely located deep in the tissue, optical sectioning at high rate of acquisition is necessary but difficult to achieve in a cost effective manner. Here we implement an accessible solution relying on HiLo microscopy to provide robust optical sectioning with a high frame rate in vivo. We show that large calcium signals can be recorded from dense neuronal populations at high acquisition rates. We quantify the optical sectioning capabilities and demonstrate the benefits of HiLo microscopy compared to wide-field microscopy for calcium imaging and 3D reconstruction. We apply HiLo microscopy to functional calcium imaging at 100 frames per second deep in biological tissues. This approach enables us to discriminate neuronal activity of motor neurons from different depths in the spinal cord of zebrafish embryos. We observe distinct time courses of calcium signals in somata and axons. We show that our method enables to remove large fluctuations of the background fluorescence. All together our setup can be implemented to provide efficient optical sectioning in vivo at low cost on a wide range of existing microscopes.

  7. DMD-based LED-illumination super-resolution and optical sectioning microscopy.

    PubMed

    Dan, Dan; Lei, Ming; Yao, Baoli; Wang, Wen; Winterhalder, Martin; Zumbusch, Andreas; Qi, Yujiao; Xia, Liang; Yan, Shaohui; Yang, Yanlong; Gao, Peng; Ye, Tong; Zhao, Wei

    2013-01-01

    Super-resolution three-dimensional (3D) optical microscopy has incomparable advantages over other high-resolution microscopic technologies, such as electron microscopy and atomic force microscopy, in the study of biological molecules, pathways and events in live cells and tissues. We present a novel approach of structured illumination microscopy (SIM) by using a digital micromirror device (DMD) for fringe projection and a low-coherence LED light for illumination. The lateral resolution of 90 nm and the optical sectioning depth of 120 μm were achieved. The maximum acquisition speed for 3D imaging in the optical sectioning mode was 1.6×10(7) pixels/second, which was mainly limited by the sensitivity and speed of the CCD camera. In contrast to other SIM techniques, the DMD-based LED-illumination SIM is cost-effective, ease of multi-wavelength switchable and speckle-noise-free. The 2D super-resolution and 3D optical sectioning modalities can be easily switched and applied to either fluorescent or non-fluorescent specimens.

  8. Optics for Advanced Neutron Imaging and Scattering

    SciTech Connect

    Moncton, David E.; Khaykovich, Boris

    2016-03-30

    During the report period, we continued the work as outlined in the original proposal. We have analyzed potential optical designs of Wolter mirrors for the neutron-imaging instrument VENUS, which is under construction at SNS. In parallel, we have conducted the initial polarized imaging experiment at Helmholtz Zentrum, Berlin, one of very few of currently available polarized-imaging facilities worldwide.

  9. Advanced lightweight optics development for space applications

    SciTech Connect

    Bilbro, James W.

    1998-01-15

    A considerable amount of effort over the past year has been devoted to exploring ultra-lightweight optics for two specific NASA programs, the Next Generation Space Telescope (NGST), and the High Throughput X-ray Spectrometer (HTXS). Experimental investigations have been undertaken in a variety of materials including glass, composites, nickel, beryllium, Carbon fiber reinforced Silicon Carbide (CSiC), Reaction Bonded Silicon Carbide, Chemical Vapor Deposited Silicon Carbide, and Silicon. Overall results of these investigations will be summarized, and specific details will be provided concerning the in-house development of ultra-lightweight nickel replication for both grazing incidence and normal incidence optics. This will include x-ray test results of the grazing incidence optic and cryogenic test results of the normal incidence optic. The status of two 1.5 meter diameter demonstration mirrors for NGST will also be presented. These two demonstrations are aimed at establishing the capability to manufacture and test mirrors that have an areal density of 15 kilograms per square meter. Efforts in thin membrane mirrors and Fresnel lenses will also be briefly discussed.

  10. Advances in superresolution optical fluctuation imaging (SOFI)

    PubMed Central

    Dertinger, Thomas; Pallaoro, Alessia; Braun, Gary; Ly, Sonny; Laurence, Ted A.; Weiss, Shimon

    2013-01-01

    We review the concept of superresolution optical fluctuation imaging (SOFI), discuss its attributes and trade-offs (in comparison with other superresolution methods), and present superresolved images taken on samples stained with quantum dots, organic dyes, and plasmonic metal nanoparticles. We also discuss the prospects of SOFI for live cell superresolution imaging and for imaging with other (non-fluorescent) contrasts. PMID:23672771

  11. Defect study in fused silica using near field scanning optical microscopy

    SciTech Connect

    Yan, M.; Wang, L.; Siekhaus, W.; Kozlowski, M.; Yang, J.; Mohideen, U.

    1998-01-21

    Surface defects in fused silica have been characterized using Near Field Scanning Optical Microscopy (NSOM). Using total internal reflection of a p- or s- polarized laser beam, optical scattering from defects located on the surface itself as well as in the subsurface layer of polished fused silica has been measured by NSOM. The local scattering intensity has been compared with simultaneously measured surface topography. In addition, surface defects intentionally created on a fused silica surface by nano-indentation have been used to establish a correlation between optical scattering of s- and p- polarized light, surface morphology and the well known subsurface stress-field associated with nano-indentation.

  12. Photonic Torque Microscopy of the Nonconservative Force Field for Optically Trapped Silicon Nanowires.

    PubMed

    Irrera, Alessia; Magazzù, Alessandro; Artoni, Pietro; Simpson, Stephen H; Hanna, Simon; Jones, Philip H; Priolo, Francesco; Gucciardi, Pietro Giuseppe; Maragò, Onofrio M

    2016-07-13

    We measure, by photonic torque microscopy, the nonconservative rotational motion arising from the transverse components of the radiation pressure on optically trapped, ultrathin silicon nanowires. Unlike spherical particles, we find that nonconservative effects have a significant influence on the nanowire dynamics in the trap. We show that the extreme shape of the trapped nanowires yields a transverse component of the radiation pressure that results in an orbital rotation of the nanowire about the trap axis. We study the resulting motion as a function of optical power and nanowire length, discussing its size-scaling behavior. These shape-dependent nonconservative effects have implications for optical force calibration and optomechanics with levitated nonspherical particles.

  13. Super-resolution spinning-disk confocal microscopy using optical photon reassignment.

    PubMed

    Azuma, Takuya; Kei, Takayuki

    2015-06-01

    Spinning-disk confocal microscopy is a proven technology for investigating 3D structures of biological specimens. Here we report a super-resolution method based on spinning-disk confocal microscopy that optically improves lateral resolution by a factor of 1.37 with a single exposure. Moreover, deconvolution yields twofold improvement over the diffraction limit. With the help of newly modified Nipkow disk which comprises pinholes and micro-lenses on the front and back respectively, emitted photons from specimen can be optically reassigned to the most probable locations they originate from. Consequently, the improvement in resolution is achieved preserving inherent sectioning capabilities of confocal microscopy. This extremely simple implementation will enable reliable observations at super high resolution in biomedical routine research.

  14. Multimodal super-resolution optical microscopy visualizes the close connection between membrane and the cytoskeleton in liver sinusoidal endothelial cell fenestrations

    NASA Astrophysics Data System (ADS)

    Mönkemöller, Viola; Øie, Cristina; Hübner, Wolfgang; Huser, Thomas; McCourt, Peter

    2015-11-01

    Liver sinusoidal endothelial cells (LSECs) act as a filter between blood and the hepatocytes. LSECs are highly fenestrated cells; they contain transcellular pores with diameters between 50 to 200 nm. The small sizes of the fenestrae have so far prohibited any functional analysis with standard and advanced light microscopy techniques. Only the advent of super-resolution optical fluorescence microscopy now permits the recording of such small cellular structures. Here, we demonstrate the complementary use of two different super-resolution optical microscopy modalities, 3D structured illumination microscopy (3D-SIM) and single molecule localization microscopy in a common optical platform to obtain new insights into the association between the cytoskeleton and the plasma membrane that supports the formation of fenestrations. We applied 3D-SIM to multi-color stained LSECs to acquire highly resolved overviews of large sample areas. We then further increased the spatial resolution for imaging fenestrations by single molecule localization microscopy applied to select small locations of interest in the same sample on the same microscope setup. We optimized the use of fluorescent membrane stains for these imaging conditions. The combination of these techniques offers a unique opportunity to significantly improve studies of subcellular ultrastructures such as LSEC fenestrations.

  15. Multimodal super-resolution optical microscopy visualizes the close connection between membrane and the cytoskeleton in liver sinusoidal endothelial cell fenestrations.

    PubMed

    Mönkemöller, Viola; Øie, Cristina; Hübner, Wolfgang; Huser, Thomas; McCourt, Peter

    2015-11-09

    Liver sinusoidal endothelial cells (LSECs) act as a filter between blood and the hepatocytes. LSECs are highly fenestrated cells; they contain transcellular pores with diameters between 50 to 200 nm. The small sizes of the fenestrae have so far prohibited any functional analysis with standard and advanced light microscopy techniques. Only the advent of super-resolution optical fluorescence microscopy now permits the recording of such small cellular structures. Here, we demonstrate the complementary use of two different super-resolution optical microscopy modalities, 3D structured illumination microscopy (3D-SIM) and single molecule localization microscopy in a common optical platform to obtain new insights into the association between the cytoskeleton and the plasma membrane that supports the formation of fenestrations. We applied 3D-SIM to multi-color stained LSECs to acquire highly resolved overviews of large sample areas. We then further increased the spatial resolution for imaging fenestrations by single molecule localization microscopy applied to select small locations of interest in the same sample on the same microscope setup. We optimized the use of fluorescent membrane stains for these imaging conditions. The combination of these techniques offers a unique opportunity to significantly improve studies of subcellular ultrastructures such as LSEC fenestrations.

  16. Ultrasonic near-field optical microscopy using a plasmonic nanofocusing probe

    NASA Astrophysics Data System (ADS)

    Ahn, Phillip; Zhang, Zhen; Sun, Cheng; Balogun, Oluwaseyi

    2013-06-01

    Ultrasonic waves are sensitive to the elastic properties of solids and have been applied in a variety of nondestructive materials characterization and metrology applications. The spatial resolution of established ultrasound techniques is limited to the order of the ultrasound wavelength, which is insufficient for nanomechanical characterization and imaging of nanoscale aspects of a material microstructure. Here, we report of an ultrasonic near-field optical microscopy (UNOM) technique that enables local mapping of ultrasound with deep sub-optical wavelength spatial resolution. In this technique, ultrasonic waves generated by a pulsed laser are detected by a scanning near-field optical probe over a broad frequency bandwidth. The scanning probe features a plasmonic nano-focusing lens that concentrates light to a strongly localized focal spot at the tip of the probe. The plasmonic probe enhances the scattering of evanescent light at the probe-tip and enables reliable measurement of the dynamic motion of a vibrating surface. The measurements made by the UNOM are purely optical; therefore, it is independent of mechanical coupling between the probe and the sample, which is one of the limitations of force based scanning probe microscopy methods. The UNOM technique allows for spatially and temporally resolved optical measurements of ultrasound with greater penetration depth, and it combines the benefits of local sensitivity to elastic and optical properties. Experimental results are presented, which demonstrate the potential of the technique for local mapping of subsurface optical absorbers in a soft material with high spatial resolution.

  17. An integrated instrumental setup for the combination of atomic force microscopy with optical spectroscopy.

    PubMed

    Owen, R J; Heyes, C D; Knebel, D; Röcker, C; Nienhaus, G U

    2006-07-01

    In recent years, the study of single biomolecules using fluorescence microscopy and atomic force microscopy (AFM) techniques has resulted in a plethora of new information regarding the physics underlying these complex biological systems. It is especially advantageous to be able to measure the optical, topographical, and mechanical properties of single molecules simultaneously. Here an AFM is used that is especially designed for integration with an inverted optical microscope and that has a near-infrared light source (850 nm) to eliminate interference between the optical experiment and the AFM operation. The Tip Assisted Optics (TAO) system consists of an additional 100 x 100-microm(2) X-Y scanner for the sample, which can be independently and simultaneously used with the AFM scanner. This allows the offset to be removed between the confocal optical image obtained with the sample scanner and the simultaneously acquired AFM topography image. The tip can be positioned exactly into the optical focus while the user can still navigate within the AFM image for imaging or manipulation of the sample. Thus the tip-enhancement effect can be maximized and it becomes possible to perform single molecule manipulation experiments within the focus of a confocal optical image. Here this is applied to simultaneous measurement of single quantum dot fluorescence and topography with high spatial resolution.

  18. Adaptive optics in spinning disk microscopy: improved contrast and brightness by a simple and fast method.

    PubMed

    Fraisier, V; Clouvel, G; Jasaitis, A; Dimitrov, A; Piolot, T; Salamero, J

    2015-09-01

    Multiconfocal microscopy gives a good compromise between fast imaging and reasonable resolution. However, the low intensity of live fluorescent emitters is a major limitation to this technique. Aberrations induced by the optical setup, especially the mismatch of the refractive index and the biological sample itself, distort the point spread function and further reduce the amount of detected photons. Altogether, this leads to impaired image quality, preventing accurate analysis of molecular processes in biological samples and imaging deep in the sample. The amount of detected fluorescence can be improved with adaptive optics. Here, we used a compact adaptive optics module (adaptive optics box for sectioning optical microscopy), which was specifically designed for spinning disk confocal microscopy. The module overcomes undesired anomalies by correcting for most of the aberrations in confocal imaging. Existing aberration detection methods require prior illumination, which bleaches the sample. To avoid multiple exposures of the sample, we established an experimental model describing the depth dependence of major aberrations. This model allows us to correct for those aberrations when performing a z-stack, gradually increasing the amplitude of the correction with depth. It does not require illumination of the sample for aberration detection, thus minimizing photobleaching and phototoxicity. With this model, we improved both signal-to-background ratio and image contrast. Here, we present comparative studies on a variety of biological samples.

  19. Optical biopsy in high-speed handheld miniaturized multifocal multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    Kim, Daekeun; Kim, Ki Hean; Yazdanfar, Siavash; So, Peter T. C.

    2005-03-01

    Histological analysis is the clinical standard for assessing tissue health and the identification of pathological states. Its invasive nature dictates that its use should be minimized without compromising diagnostic accuracy. A promising method for minimally invasive histological analysis is optical biopsy, which provides cross sectional or 3D images without any physical sectionings. Optical biopsy method based on multiphoton excitation microscopy can image cross-sectional image for deep tissue structures with subcellular resolution based on tissue endogenous fluorescence molecules. Despite its suitability for tissue imaging, multiphoton microscopy has not been used for in vivo clinical applications due to both compactness and imaging speed problems. We are developing a high-speed, handheld, miniaturized multifocal multiphoton microscope (H2M4) as an optical biopsy probe to enable optical biopsy with subcellular resolution. We incorporate a compact raster scanning actuator based on optimizing a piezo-driven tip tilt mirror by increasing its bandwidth, and reducing its nonlinearity. For flexible light delivery, we choose a photonic bandgap crystal fiber, which transmits ultrashort pulsed laser delivery with reduced spectral distortion and pulse width broadening. We further demonstrate that this fiber produces minimal spatial mode distortion and can achieve comparable image point spread function (PSF) as free space delivery. We further investigate the applicability of multiphoton microscopy for clinical dermal investigation by imaging ex vivo human skins with both normal and abnormal physiologies. This demonstrates the performance of H2M4 and the possibility of optical biopsy for diagnosing skin diseases.

  20. Optical Measurements On Advanced Performance Domes

    NASA Astrophysics Data System (ADS)

    Archibald, P. C.; Burge, D. K.

    1984-12-01

    Sapphire, spinel, and ALON (aluminum oxynitride) have been identified as candidate dome materials for ultraviolet through 5 μm wavelength applications. They possess optical, mechanical, and thermal properties that are superior to those of currently used Irtran-1 domes. Optical performance of these materials in the visible wavelength region far exceeds that of Irtran-1, while infrared properties reported here vary from worse than to better than Irtran-1 domes. Reported in this paper are measurements of optical scatter and transmittance at 0.4762, 0.6471, and 3.39 μm, which represent a large range of values obtained on these materials in dome form. Processing changes over the last few years have produced improvements in both scatter and transmittance, provided that a good surface finish is maintained. Higher index of refraction will, of course, limit the ultimate transmittance for uncoated domes of these materials to slightly less than that of Irtran-1, which has also improved in the same time period. Calculations indicate maximum transmittance at 3.39 pm to be 0.95 to 0.96 for Irtran-1 and 0.87 to 0.88 for spinel, a difference of 0.08. Current measurements at the Naval Weapons Center confirm values of 0.88 for spinel, while the best Irtran-1 dome gave a value of less than 0.92.

  1. Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda

    2015-01-01

    Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology" project will investigate newly developed optic gas sensors delivered from a Small Business Innovative Research (SBIR) Phase II effort. A ventilation test rig will be designed and fabricated to test the sensors while integrated with a Suited Manikin Test Apparatus (SMTA). Once the sensors are integrated, a series of test points will be completed to verify that the sensors can withstand Advanced Suit Portable Life Support System (PLSS) environments and associated human metabolic profiles for changes in pressure and levels of Oxygen (ppO2), carbon dioxide (ppCO2), and humidity (ppH2O).

  2. Linear semiconductor optical amplifiers for amplification of advanced modulation formats.

    PubMed

    Bonk, R; Huber, G; Vallaitis, T; Koenig, S; Schmogrow, R; Hillerkuss, D; Brenot, R; Lelarge, F; Duan, G-H; Sygletos, S; Koos, C; Freude, W; Leuthold, J

    2012-04-23

    The capability of semiconductor optical amplifiers (SOA) to amplify advanced optical modulation format signals is investigated. The input power dynamic range is studied and especially the impact of the SOA alpha factor is addressed. Our results show that the advantage of a lower alpha-factor SOA decreases for higher-order modulation formats. Experiments at 20 GBd BPSK, QPSK and 16QAM with two SOAs with different alpha factors are performed. Simulations for various modulation formats support the experimental findings.

  3. Recent advancement in optical fiber sensing for aerospace composite structures

    NASA Astrophysics Data System (ADS)

    Minakuchi, Shu; Takeda, Nobuo

    2013-12-01

    Optical fiber sensors have attracted considerable attention in health monitoring of aerospace composite structures. This paper briefly reviews our recent advancement mainly in Brillouin-based distributed sensing. Damage detection, life cycle monitoring and shape reconstruction systems applicable to large-scale composite structures are presented, and new technical concepts, "smart crack arrester" and "hierarchical sensing system", are described as well, highlighting the great potential of optical fiber sensors for the structural health monitoring (SHM) field.

  4. Advances in Optical Spectroscopy and Imaging of Breast Lesions

    SciTech Connect

    Demos, S; Vogel, A J; Gandjbakhche, A H

    2006-01-03

    A review is presented of recent advances in optical imaging and spectroscopy and the use of light for addressing breast cancer issues. Spectroscopic techniques offer the means to characterize tissue components and obtain functional information in real time. Three-dimensional optical imaging of the breast using various illumination and signal collection schemes in combination with image reconstruction algorithms may provide a new tool for cancer detection and monitoring of treatment.

  5. Advanced Sensors Boost Optical Communication, Imaging

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Brooklyn, New York-based Amplification Technologies Inc. (ATI), employed Phase I and II SBIR funding from NASA s Jet Propulsion Laboratory to forward the company's solid-state photomultiplier technology. Under the SBIR, ATI developed a small, energy-efficient, extremely high-gain sensor capable of detecting light down to single photons in the near infrared wavelength range. The company has commercialized this technology in the form of its NIRDAPD photomultiplier, ideal for use in free space optical communications, lidar and ladar, night vision goggles, and other light sensing applications.

  6. Recognition of serous ovarian tumors in human samples by multimodal nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Adur, Javier; Pelegati, Vitor B.; Costa, Leverson F. L.; Pietro, Luciana; de Thomaz, Andre A.; Almeida, Diogo B.; Bottcher-Luiz, Fatima; Andrade, Liliana A. L. A.; Cesar, Carlos L.

    2011-09-01

    We used a multimodal nonlinear optics microscopy, specifically two-photon excited fluorescence (TPEF), second and third harmonic generation (SHG/THG) microscopies, to observe pathological conditions of ovarian tissues obtained from human samples. We show that strong TPEF + SHG + THG signals can be obtained in fixed samples stained with hematoxylin and eosin (H&E) stored for a very long time, and that H&E staining enhanced the THG signal. We then used the multimodal TPEF-SHG-THG microscopies in a stored file of H&E stained samples of human ovarian cancer to obtain complementary information about the epithelium/stromal interface, such as the transformation of epithelium surface (THG) and the overall fibrillary tissue architecture (SHG). This multicontrast nonlinear optics microscopy is able to not only differentiate between cancerous and healthy tissue, but can also distinguish between normal, benign, borderline, and malignant specimens according to their collagen disposition and compression levels within the extracellular matrix. The dimensions of the layers of epithelia can also be measured precisely and automatically. Our data demonstrate that optical techniques can detect pathological changes associated with ovarian cancer.

  7. Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials.

    PubMed

    Ke, Xiaoxing; Bittencourt, Carla; Van Tendeloo, Gustaaf

    2015-01-01

    A major revolution for electron microscopy in the past decade is the introduction of aberration correction, which enables one to increase both the spatial resolution and the energy resolution to the optical limit. Aberration correction has contributed significantly to the imaging at low operating voltages. This is crucial for carbon-based nanomaterials which are sensitive to electron irradiation. The research of carbon nanomaterials and nanohybrids, in particular the fundamental understanding of defects and interfaces, can now be carried out in unprecedented detail by aberration-corrected transmission electron microscopy (AC-TEM). This review discusses new possibilities and limits of AC-TEM at low voltage, including the structural imaging at atomic resolution, in three dimensions and spectroscopic investigation of chemistry and bonding. In situ TEM of carbon-based nanomaterials is discussed and illustrated through recent reports with particular emphasis on the underlying physics of interactions between electrons and carbon atoms.

  8. Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

    PubMed Central

    Bittencourt, Carla; Van Tendeloo, Gustaaf

    2015-01-01

    Summary A major revolution for electron microscopy in the past decade is the introduction of aberration correction, which enables one to increase both the spatial resolution and the energy resolution to the optical limit. Aberration correction has contributed significantly to the imaging at low operating voltages. This is crucial for carbon-based nanomaterials which are sensitive to electron irradiation. The research of carbon nanomaterials and nanohybrids, in particular the fundamental understanding of defects and interfaces, can now be carried out in unprecedented detail by aberration-corrected transmission electron microscopy (AC-TEM). This review discusses new possibilities and limits of AC-TEM at low voltage, including the structural imaging at atomic resolution, in three dimensions and spectroscopic investigation of chemistry and bonding. In situ TEM of carbon-based nanomaterials is discussed and illustrated through recent reports with particular emphasis on the underlying physics of interactions between electrons and carbon atoms. PMID:26425406

  9. Recent advances in ALON optical ceramic

    NASA Astrophysics Data System (ADS)

    Wahl, Joseph M.; Hartnett, Thomas M.; Goldman, Lee M.; Twedt, Richard; Warner, Charles

    2005-05-01

    Aluminum Oxynitride (ALONTM Optical Ceramic) is a transparent ceramic material which combines transparency from the UV to the MWIR with excellent mechanical properties. ALON"s optical and mechanical properties are isotropic by virtue of its cubic crystalline structure. Consequently, ALON is transparent in its polycrystalline form and can be made by conventional powder processing techniques. This combination of properties and manufacturability make ALON suitable for a range of applications from IR windows, domes and lenses to transparent armor. The technology for producing transparent ALON was developed at Raytheon and has been transferred to Surmet Corporation where it is currently in production. Surmet is currently selling ALON into a number of military (e.g., windows and domes) and commercial (e.g., supermarket scanner windows) applications. The capability to manufacture large ALON windows for both sensor window and armor applications is in place. ALON windows up to 20x30 inches have been fabricated. In addition, the capability to shape and polish these large and curved windows is being developed and demonstrated at Surmet. Complex shapes, both hyper-hemispherical and conformal, are also under development and will be described.

  10. Integrated modeling of advanced optical systems

    NASA Technical Reports Server (NTRS)

    Briggs, Hugh C.; Needels, Laura; Levine, B. Martin

    1993-01-01

    This poster session paper describes an integrated modeling and analysis capability being developed at JPL under funding provided by the JPL Director's Discretionary Fund and the JPL Control/Structure Interaction Program (CSI). The posters briefly summarize the program capabilities and illustrate them with an example problem. The computer programs developed under this effort will provide an unprecedented capability for integrated modeling and design of high performance optical spacecraft. The engineering disciplines supported include structural dynamics, controls, optics and thermodynamics. Such tools are needed in order to evaluate the end-to-end system performance of spacecraft such as OSI, POINTS, and SMMM. This paper illustrates the proof-of-concept tools that have been developed to establish the technology requirements and demonstrate the new features of integrated modeling and design. The current program also includes implementation of a prototype tool based upon the CAESY environment being developed under the NASA Guidance and Control Research and Technology Computational Controls Program. This prototype will be available late in FY-92. The development plan proposes a major software production effort to fabricate, deliver, support and maintain a national-class tool from FY-93 through FY-95.

  11. Fluorescent Nanodiamond-Gold Hybrid Particles for Multimodal Optical and Electron Microscopy Cellular Imaging.

    PubMed

    Liu, Weina; Naydenov, Boris; Chakrabortty, Sabyasachi; Wuensch, Bettina; Hübner, Kristina; Ritz, Sandra; Cölfen, Helmut; Barth, Holger; Koynov, Kaloian; Qi, Haoyuan; Leiter, Robert; Reuter, Rolf; Wrachtrup, Jörg; Boldt, Felix; Scheuer, Jonas; Kaiser, Ute; Sison, Miguel; Lasser, Theo; Tinnefeld, Philip; Jelezko, Fedor; Walther, Paul; Wu, Yuzhou; Weil, Tanja

    2016-10-12

    There is a continuous demand for imaging probes offering excellent performance in various microscopy techniques for comprehensive investigations of cellular processes by more than one technique. Fluorescent nanodiamond-gold nanoparticles (FND-Au) constitute a new class of "all-in-one" hybrid particles providing unique features for multimodal cellular imaging including optical imaging, electron microscopy, and, and potentially even quantum sensing. Confocal and optical coherence microscopy of the FND-Au allow fast investigations inside living cells via emission, scattering, and photothermal imaging techniques because the FND emission is not quenched by AuNPs. In electron microscopy, transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) analysis of FND-Au reveals greatly enhanced contrast due to the gold particles as well as an extraordinary flickering behavior in three-dimensional cellular environments originating from the nanodiamonds. The unique multimodal imaging characteristics of FND-Au enable detailed studies inside cells ranging from statistical distributions at the entire cellular level (micrometers) down to the tracking of individual particles in subcellular organelles (nanometers). Herein, the processes of endosomal membrane uptake and release of FNDs were elucidated for the first time by the imaging of individual FND-Au hybrid nanoparticles with single-particle resolution. Their convenient preparation, the availability of various surface groups, their flexible detection modalities, and their single-particle contrast in combination with the capability for endosomal penetration and low cytotoxicity make FND-Au unique candidates for multimodal optical-electronic imaging applications with great potential for emerging techniques, such as quantum sensing inside living cells.

  12. Grid-enhanced X-ray coded aperture microscopy with polycapillary optics.

    PubMed

    Sowa, Katarzyna M; Last, Arndt; Korecki, Paweł

    2017-03-21

    Polycapillary devices focus X-rays by means of multiple reflections of X-rays in arrays of bent glass capillaries. The size of the focal spot (typically 10-100 μm) limits the resolution of scanning, absorption and phase-contrast X-ray imaging using these devices. At the expense of a moderate resolution, polycapillary elements provide high intensity and are frequently used for X-ray micro-imaging with both synchrotrons and X-ray tubes. Recent studies have shown that the internal microstructure of such an optics can be used as a coded aperture that encodes high-resolution information about objects located inside the focal spot. However, further improvements to this variant of X-ray microscopy will require the challenging fabrication of tailored devices with a well-defined capillary microstructure. Here, we show that submicron coded aperture microscopy can be realized using a periodic grid that is placed at the output surface of a polycapillary optics. Grid-enhanced X-ray coded aperture microscopy with polycapillary optics does not rely on the specific microstructure of the optics but rather takes advantage only of its focusing properties. Hence, submicron X-ray imaging can be realized with standard polycapillary devices and existing set-ups for micro X-ray fluorescence spectroscopy.

  13. Grid-enhanced X-ray coded aperture microscopy with polycapillary optics

    NASA Astrophysics Data System (ADS)

    Sowa, Katarzyna M.; Last, Arndt; Korecki, Paweł

    2017-03-01

    Polycapillary devices focus X-rays by means of multiple reflections of X-rays in arrays of bent glass capillaries. The size of the focal spot (typically 10–100 μm) limits the resolution of scanning, absorption and phase-contrast X-ray imaging using these devices. At the expense of a moderate resolution, polycapillary elements provide high intensity and are frequently used for X-ray micro-imaging with both synchrotrons and X-ray tubes. Recent studies have shown that the internal microstructure of such an optics can be used as a coded aperture that encodes high-resolution information about objects located inside the focal spot. However, further improvements to this variant of X-ray microscopy will require the challenging fabrication of tailored devices with a well-defined capillary microstructure. Here, we show that submicron coded aperture microscopy can be realized using a periodic grid that is placed at the output surface of a polycapillary optics. Grid-enhanced X-ray coded aperture microscopy with polycapillary optics does not rely on the specific microstructure of the optics but rather takes advantage only of its focusing properties. Hence, submicron X-ray imaging can be realized with standard polycapillary devices and existing set-ups for micro X-ray fluorescence spectroscopy.

  14. X-ray optics for scanning fluorescence microscopy and other applications

    SciTech Connect

    Ryon, R.W.; Warburton, W.K.

    1992-05-01

    Scanning x-ray fluorescence microscopy is analogous to scanning electron microscopy. Maps of chemical element distribution are produced by scanning with a very small x-ray beam. Goal is to perform such scanning microscopy with resolution in the range of <1 to 10 {mu}m, using standard laboratory x-ray tubes. We are investigating mirror optics in the Kirkpatrick-Baez (K-B) configuration. K-B optics uses two curved mirrors mounted orthogonally along the optical axis. The first mirror provides vertical focus, the second mirror provides horizontal focus. We have used two types of mirrors: synthetic multilayers and crystals. Multilayer mirrors are used with lower energy radiation such as Cu K{alpha}. At higher energies such as Ag K{alpha}, silicon wafers are used in order to increase the incidence angles and thereby the photon collection efficiency. In order to increase the surface area of multilayers which reflects x-rays at the Bragg angle, we have designed mirrors with the spacing between layers graded along the optic axis in order to compensate for the changing angle of incidence. Likewise, to achieve a large reflecting surface with silicon, the wafers are placed on a specially designed lever arm which is bent into a log spiral by applying force at one end. In this way, the same diffracting angle is maintained over the entire surface of the wafer, providing a large solid angle for photon collection.

  15. Grid-enhanced X-ray coded aperture microscopy with polycapillary optics

    PubMed Central

    Sowa, Katarzyna M.; Last, Arndt; Korecki, Paweł

    2017-01-01

    Polycapillary devices focus X-rays by means of multiple reflections of X-rays in arrays of bent glass capillaries. The size of the focal spot (typically 10–100 μm) limits the resolution of scanning, absorption and phase-contrast X-ray imaging using these devices. At the expense of a moderate resolution, polycapillary elements provide high intensity and are frequently used for X-ray micro-imaging with both synchrotrons and X-ray tubes. Recent studies have shown that the internal microstructure of such an optics can be used as a coded aperture that encodes high-resolution information about objects located inside the focal spot. However, further improvements to this variant of X-ray microscopy will require the challenging fabrication of tailored devices with a well-defined capillary microstructure. Here, we show that submicron coded aperture microscopy can be realized using a periodic grid that is placed at the output surface of a polycapillary optics. Grid-enhanced X-ray coded aperture microscopy with polycapillary optics does not rely on the specific microstructure of the optics but rather takes advantage only of its focusing properties. Hence, submicron X-ray imaging can be realized with standard polycapillary devices and existing set-ups for micro X-ray fluorescence spectroscopy. PMID:28322316

  16. Polarized 3D Raman and nanoscale near-field optical microscopy of optically inscribed surface relief gratings: chromophore orientation in azo-doped polymer films.

    PubMed

    Di Florio, Giuseppe; Bründermann, Erik; Yadavalli, Nataraja Sekhar; Santer, Svetlana; Havenith, Martina

    2014-03-14

    We have used polarized confocal Raman microspectroscopy and scanning near-field optical microscopy with a resolution of 60 nm to characterize photoinscribed grating structures of azobenzene doped polymer films on a glass support. Polarized Raman microscopy allowed determining the reorientation of the chromophores as a function of the grating phase and penetration depth of the inscribing laser in three dimensions. We found periodic patterns, which are not restricted to the surface alone, but appear also well below the surface in the bulk of the material. Near-field optical microscopy with nanoscale resolution revealed lateral two-dimensional optical contrast, which is not observable by atomic force and Raman microscopy.

  17. Advanced NDE research in electromagnetic, thermal, and coherent optics

    NASA Astrophysics Data System (ADS)

    Skinner, S. Ballou

    1992-09-01

    A new inspection technology called magneto-optic/eddy current imaging was investigated. The magneto-optic imager makes readily visible irregularities and inconsistencies in airframe components. Other research observed in electromagnetics included (1) disbond detection via resonant modal analysis; (2) AC magnetic field frequency dependence of magnetoacoustic emission; and (3) multi-view magneto-optic imaging. Research observed in the thermal group included (1) thermographic detection and characterization of corrosion in aircraft aluminum; (2) a multipurpose infrared imaging system for thermoelastic stress detection; (3) thermal diffusivity imaging of stress induced damage in composites; and (4) detection and measurement of ice formation on the space shuttle main fuel tank. Research observed in the optics group included advancements in optical nondestructive evaluation (NDE).

  18. Advanced Optical Technologies for Space Exploration

    NASA Technical Reports Server (NTRS)

    Clark, Natalie

    2007-01-01

    NASA Langley Research Center is involved in the development of photonic devices and systems for space exploration missions. Photonic technologies of particular interest are those that can be utilized for in-space communication, remote sensing, guidance navigation and control, lunar descent and landing, and rendezvous and docking. NASA Langley has recently established a class-100 clean-room which serves as a Photonics Fabrication Facility for development of prototype optoelectronic devices for aerospace applications. In this paper we discuss our design, fabrication, and testing of novel active pixels, deformable mirrors, and liquid crystal spatial light modulators. Successful implementation of these intelligent optical devices and systems in space, requires careful consideration of temperature and space radiation effects in inorganic and electronic materials. Applications including high bandwidth inertial reference units, lightweight, high precision star trackers for guidance, navigation, and control, deformable mirrors, wavefront sensing, and beam steering technologies are discussed. In addition, experimental results are presented which characterize their performance in space exploration systems.

  19. Recent advancements towards green optical networks

    NASA Astrophysics Data System (ADS)

    Davidson, Alan; Glesk, Ivan; Buis, Adrianus; Wang, Junjia; Chen, Lawrence

    2014-12-01

    Recent years have seen a rapid growth in demand for ultra high speed data transmission with end users expecting fast, high bandwidth network access. With this rapid growth in demand, data centres are under pressure to provide ever increasing data rates through their networks and at the same time improve the quality of data handling in terms of reduced latency, increased scalability and improved channel speed for users. However as data rates increase, present technology based on well-established CMOS technology is becoming increasingly difficult to scale and consequently data networks are struggling to satisfy current network demand. In this paper the interrelated issues of electronic scalability, power consumption, limited copper interconnect bandwidth and the limited speed of CMOS electronics will be explored alongside the tremendous bandwidth potential of optical fibre based photonic networks. Some applications of photonics to help alleviate the speed and latency in data networks will be discussed.

  20. Advanced optical technologies for space exploration

    NASA Astrophysics Data System (ADS)

    Clark, Natalie

    2007-09-01

    NASA Langley Research Center is involved in the development of photonic devices and systems for space exploration missions. Photonic technologies of particular interest are those that can be utilized for in-space communication, remote sensing, guidance navigation and control, lunar descent and landing, and rendezvous and docking. NASA Langley has recently established a class-100 clean-room which serves as a Photonics Fabrication Facility for development of prototype optoelectronic devices for aerospace applications. In this paper we discuss our design, fabrication, and testing of novel active pixels, deformable mirrors, and liquid crystal spatial light modulators. Successful implementation of these intelligent optical devices and systems in space, requires careful consideration of temperature and space radiation effects in inorganic and electronic materials. Applications including high bandwidth inertial reference units, lightweight, high precision star trackers for guidance, navigation, and control, deformable mirrors, wavefront sensing, and beam steering technologies are discussed. In addition, experimental results are presented which characterize their performance in space exploration systems

  1. Advanced Heat Pipes For Optical Applications

    NASA Astrophysics Data System (ADS)

    Shaubach, Robert M.; Eastman, G. Yale

    1984-12-01

    Heat pipes offer the potential of vibrationless cooling of optical surfaces while maintaining a high degree of temperature uniformity on the cooled surface. The objective of the present program is to develop and demonstrate prototype heat pipes for this application. The material of construction is silicon; the pqwer density range is 5 to 50 Watts/per square centimeter with a nominal objective of 30 W/cm2. This paper describes the first eighteen months of work, during which the contract goals were met. The program was carried out by Thermacore on Contract F33615-82-C-5127 for the Department of the Air Force, Aeronautical Systems Division, Wright-Patterson Air Force Base, Ohio. Dr. Alan K. Hopkins of the Materials Laboratory supplied technical supervision of the program for the Air Force.

  2. Advanced Time-Resolved Fluorescence Microscopy Techniques for the Investigation of Peptide Self-Assembly

    NASA Astrophysics Data System (ADS)

    Anthony, Neil R.

    The ubiquitous cross beta sheet peptide motif is implicated in numerous neurodegenerative diseases while at the same time offers remarkable potential for constructing isomorphic high-performance bionanomaterials. Despite an emerging understanding of the complex folding landscape of cross beta structures in determining disease etiology and final structure, we lack knowledge of the critical initial stages of nucleation and growth. In this dissertation, I advance our understanding of these key stages in the cross-beta nucleation and growth pathways using cutting-edge microscopy techniques. In addition, I present a new combined time-resolved fluorescence analysis technique with the potential to advance our current understanding of subtle molecular level interactions that play a pivotal role in peptide self-assembly. Using the central nucleating core of Alzheimer's Amyloid-beta protein, Abeta(16 22), as a model system, utilizing electron, time-resolved, and non-linear microscopy, I capture the initial and transient nucleation stages of peptide assembly into the cross beta motif. In addition, I have characterized the nucleation pathway, from monomer to paracrystalline nanotubes in terms of morphology and fluorescence lifetime, corroborating the predicted desolvation process that occurs prior to cross-beta nucleation. Concurrently, I have identified unique heterogeneous cross beta domains contained within individual nanotube structures, which have potential bionanomaterials applications. Finally, I describe a combined fluorescence theory and analysis technique that dramatically increases the sensitivity of current time-resolved techniques. Together these studies demonstrate the potential for advanced microscopy techniques in the identification and characterization of the cross-beta folding pathway, which will further our understanding of both amyloidogenesis and bionanomaterials.

  3. Measurement of dynamic cell-induced 3D displacement fields in vitro for traction force optical coherence microscopy

    PubMed Central

    Mulligan, Jeffrey A.; Bordeleau, François; Reinhart-King, Cynthia A.; Adie, Steven G.

    2017-01-01

    Traction force microscopy (TFM) is a method used to study the forces exerted by cells as they sense and interact with their environment. Cell forces play a role in processes that take place over a wide range of spatiotemporal scales, and so it is desirable that TFM makes use of imaging modalities that can effectively capture the dynamics associated with these processes. To date, confocal microscopy has been the imaging modality of choice to perform TFM in 3D settings, although multiple factors limit its spatiotemporal coverage. We propose traction force optical coherence microscopy (TF-OCM) as a novel technique that may offer enhanced spatial coverage and temporal sampling compared to current methods used for volumetric TFM studies. Reconstructed volumetric OCM data sets were used to compute time-lapse extracellular matrix deformations resulting from cell forces in 3D culture. These matrix deformations revealed clear differences that can be attributed to the dynamic forces exerted by normal versus contractility-inhibited NIH-3T3 fibroblasts embedded within 3D Matrigel matrices. Our results are the first step toward the realization of 3D TF-OCM, and they highlight the potential use of OCM as a platform for advancing cell mechanics research. PMID:28271010

  4. Potential Challenges in Near-Field Scanning Optical Microscopy for Space Applications

    NASA Technical Reports Server (NTRS)

    Vikram, Chandra S.; Witherow, William K.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Near-field scanning optical microscopy (NSOM) also called scanning near-field optical microscopy (SNOM) is now well accepted as a powerful tool for sub-wavelength (nanoscale in the optical region) spatial resolution microscopy and a large number of related tasks. The importance lies in the fact of strategic advantages of standard microscopy but with significantly enhanced resolution. Since many modern optical diagnostic techniques have found useful applications in space, it is logical to consider the future role of NSOM in such situations. For example, protein crystal growth study under microgravity conditions is a valid candidate. If applied successfully, processes at molecular level can be studied during the growth. NSOM has already been demonstrated to be useful for the study of such crystals here on earth. The basic principle of NSOM can be illustrated. The illumination-collection mode is shown although several other possible approaches exist. In this, the sample is illuminated and the light from the sample is collected through the same tiny aperture opening. A tapered optical fiber is scanned near the sample surface. The tip is coated generally with a metal with a sub-wavelength aperture opening. The tip-sample distance is maintained constant while scanning. Thus, the optical signal available for collection is generally a function of the optical properties of the sample surface. Since the aperture is sub-wavelength in diameter and the tip is held very close (again in the sub-wavelength domain) to the surface, the lateral resolution in the sub-wavelength domain is obtained. Thus, the typical wavelength- order resolution of ordinary microscopy can be significantly enhanced while maintaining the strategic advantages (no need of sample in vacuum chamber, electron beams, etc). Commercial NSOM systems play a key role in the success and widespread acceptance of the tool. These commercial systems work fairly well in laboratory conditions on earth. However, they may

  5. A versatile implementation of pulsed optical excitation in scanning tunneling microscopy.

    PubMed

    Kloth, P; Thias, T; Bunjes, O; von der Haar, J; Wenderoth, M

    2016-12-01

    We present a combination of pulsed optical excitation and scanning tunneling microscopy with a highly flexible pulse generation method. A high frequency arbitrary wave generator drives a gigahertz electro-optical modulator, which processes a continuous-wave laser beam of a low-noise laser diode into the desired wave shape. For pump-probe excitation we generate optical pulse series in an all-electronic way. Thereby we can easily adapt parameters like pulse amplitude, width, or repetition cycle to the demands of the experiment. This setup is used to study different dynamic processes at the GaAs(110) surface. Separating thermally induced effects from electrically induced effects allows us to quantify the thermal contribution of the optical excitation in STM experiments. Time-resolved decay spectra of the photo-generated electron-hole pairs demonstrate the nanoscale spatial resolution.

  6. Simultaneous imaging of magnetic field and temperature distributions by magneto optical indicator microscopy.

    PubMed

    Lee, Hanju; Jeon, Sunghoon; Friedman, Barry; Lee, Kiejin

    2017-03-02

    We report a simultaneous imaging method of the temperature and the magnetic field distributions based on the magneto optical indicator microscopy. The present method utilizes an optical indicator composed of a bismuth-substituted yttrium iron garnet thin film, and visualizes the magnetic field and temperature distributions through the magneto-optical effect and the temperature dependent optical absorption of the garnet thin film. By using a printed circuit board that carries an electric current as a device under test, we showed that the present method can visualize the magnetic field and temperature distribution simultaneously with a comparable temperature sensitivity (0.2 K) to that of existing conventional thermal imagers. The present technique provides a practical way to get a high resolution magnetic and thermal image at the same time, which is valuable in investigating how thermal variation results in a change of the operation state of a micrometer sized electronic device or material.

  7. A versatile implementation of pulsed optical excitation in scanning tunneling microscopy

    NASA Astrophysics Data System (ADS)

    Kloth, P.; Thias, T.; Bunjes, O.; von der Haar, J.; Wenderoth, M.

    2016-12-01

    We present a combination of pulsed optical excitation and scanning tunneling microscopy with a highly flexible pulse generation method. A high frequency arbitrary wave generator drives a gigahertz electro-optical modulator, which processes a continuous-wave laser beam of a low-noise laser diode into the desired wave shape. For pump-probe excitation we generate optical pulse series in an all-electronic way. Thereby we can easily adapt parameters like pulse amplitude, width, or repetition cycle to the demands of the experiment. This setup is used to study different dynamic processes at the GaAs(110) surface. Separating thermally induced effects from electrically induced effects allows us to quantify the thermal contribution of the optical excitation in STM experiments. Time-resolved decay spectra of the photo-generated electron-hole pairs demonstrate the nanoscale spatial resolution.

  8. Simultaneous imaging of magnetic field and temperature distributions by magneto optical indicator microscopy

    PubMed Central

    Lee, Hanju; Jeon, Sunghoon; Friedman, Barry; Lee, Kiejin

    2017-01-01

    We report a simultaneous imaging method of the temperature and the magnetic field distributions based on the magneto optical indicator microscopy. The present method utilizes an optical indicator composed of a bismuth-substituted yttrium iron garnet thin film, and visualizes the magnetic field and temperature distributions through the magneto-optical effect and the temperature dependent optical absorption of the garnet thin film. By using a printed circuit board that carries an electric current as a device under test, we showed that the present method can visualize the magnetic field and temperature distribution simultaneously with a comparable temperature sensitivity (0.2 K) to that of existing conventional thermal imagers. The present technique provides a practical way to get a high resolution magnetic and thermal image at the same time, which is valuable in investigating how thermal variation results in a change of the operation state of a micrometer sized electronic device or material. PMID:28252018

  9. Simultaneous imaging of magnetic field and temperature distributions by magneto optical indicator microscopy

    NASA Astrophysics Data System (ADS)

    Lee, Hanju; Jeon, Sunghoon; Friedman, Barry; Lee, Kiejin

    2017-03-01

    We report a simultaneous imaging method of the temperature and the magnetic field distributions based on the magneto optical indicator microscopy. The present method utilizes an optical indicator composed of a bismuth-substituted yttrium iron garnet thin film, and visualizes the magnetic field and temperature distributions through the magneto-optical effect and the temperature dependent optical absorption of the garnet thin film. By using a printed circuit board that carries an electric current as a device under test, we showed that the present method can visualize the magnetic field and temperature distribution simultaneously with a comparable temperature sensitivity (0.2 K) to that of existing conventional thermal imagers. The present technique provides a practical way to get a high resolution magnetic and thermal image at the same time, which is valuable in investigating how thermal variation results in a change of the operation state of a micrometer sized electronic device or material.

  10. Advanced optical interference filters based on metal and dielectric layers.

    PubMed

    Begou, Thomas; Lemarchand, Fabien; Lumeau, Julien

    2016-09-05

    In this paper, we investigate the design and the fabrication of an advanced optical interference filter based on metal and dielectric layers. This filter respects the specifications of the 2016 OIC manufacturing problem contest. We study and present all the challenges and solutions that allowed achieving a low deviation between the fabricated prototype and the target.

  11. Revealing T-Tubules in Striated Muscle with New Optical Super-Resolution Microscopy Techniquess.

    PubMed

    Jayasinghe, Isuru D; Clowsley, Alexander H; Munro, Michelle; Hou, Yufeng; Crossman, David J; Soeller, Christian

    2015-01-07

    The t-tubular system plays a central role in the synchronisation of calcium signalling and excitation-contraction coupling in most striated muscle cells. Light microscopy has been used for imaging t-tubules for well over 100 years and together with electron microscopy (EM), has revealed the three-dimensional complexities of the t-system topology within cardiomyocytes and skeletal muscle fibres from a range of species. The emerging super-resolution single molecule localisation microscopy (SMLM) techniques are offering a near 10-fold improvement over the resolution of conventional fluorescence light microscopy methods, with the ability to spectrally resolve nanometre scale distributions of multiple molecular targets. In conjunction with the next generation of electron microscopy, SMLM has allowed the visualisation and quantification of intricate t-tubule morphologies within large areas of muscle cells at an unprecedented level of detail. In this paper, we review recent advancements in the t-tubule structural biology with the utility of various microscopy techniques. We outline the technical considerations in adapting SMLM to study t-tubules and its potential to further our understanding of the molecular processes that underlie the sub-micron scale structural alterations observed in a range of muscle pathologies.

  12. Multimodal optical microscopy in combination with gold nanorods for cancer cell imaging.

    PubMed

    Cao, Cai-jun; Li, De-rong; Chen, Chao-xiong; Yang, Xiao-yun; Hu, Juan; Yang, Yong; Zhang, Chun-yang

    2012-12-01

    The multimodal optical imaging technique, which utilizes nonlinear and linear optical processes, plays an important role in biological and biomedical research. As second-order nonlinear phenomenon, the two-photon luminescence (TPL) results from the nonlinear excitation of fluorescent molecules, while the second harmonic generation (SHG) depends on the second order nonlinear polarization, orientation, and noncentrosymmetric properties of molecules. In contrast, the linear resonance light scattering (RLS) occurs when the molecules are excited by a light beam with a wavelength close to their absorption bands. Since SHG, TPL, and RLS involve different kinds of optical processes, they might be used in parallel to provide complementary information about the structure and function of cells and tissues. Herein, we develop for the first time a multimodal optical microscopy with the capability of simultaneous SHG, TPL, and RLS imaging. We analyze theoretically and demonstrate experimentally the near-infrared irradiation-induced SHG, TPL, and RLS from the gold nanorods with nanometer spatial resolution. With the gold nanorods as the contrast agents, we further demonstrate the simultaneous SHG, TPL, and RLS imaging of A431 human epithelial skin cancer cells. This multimodal optical microscopy might provide a reliable and complementary approach for biological and biomedical research.

  13. Structured light optical microscopy for three-dimensional reconstruction of technical surfaces

    NASA Astrophysics Data System (ADS)

    Kettel, Johannes; Reinecke, Holger; Müller, Claas

    2016-04-01

    In microsystems technology quality control of micro structured surfaces with different surface properties is playing an ever more important role. The process of quality control incorporates three-dimensional (3D) reconstruction of specularand diffusive reflecting technical surfaces. Due to the demand on high measurement accuracy and data acquisition rates, structured light optical microscopy has become a valuable solution to solve this problem providing high vertical and lateral resolution. However, 3D reconstruction of specular reflecting technical surfaces still remains a challenge to optical measurement principles. In this paper we present a measurement principle based on structured light optical microscopy which enables 3D reconstruction of specular- and diffusive reflecting technical surfaces. It is realized using two light paths of a stereo microscope equipped with different magnification levels. The right optical path of the stereo microscope is used to project structured light onto the object surface. The left optical path is used to capture the structured illuminated object surface with a camera. Structured light patterns are generated by a Digital Light Processing (DLP) device in combination with a high power Light Emitting Diode (LED). Structured light patterns are realized as a matrix of discrete light spots to illuminate defined areas on the object surface. The introduced measurement principle is based on multiple and parallel processed point measurements. Analysis of the measured Point Spread Function (PSF) by pattern recognition and model fitting algorithms enables the precise calculation of 3D coordinates. Using exemplary technical surfaces we demonstrate the successful application of our measurement principle.

  14. Multimodal optical microscopy in combination with gold nanorods for cancer cell imaging

    NASA Astrophysics Data System (ADS)

    Cao, Cai-jun; Li, De-rong; Chen, Chao-xiong; Yang, Xiao-yun; Hu, Juan; Yang, Yong; Zhang, Chun-yang

    2012-12-01

    The multimodal optical imaging technique, which utilizes nonlinear and linear optical processes, plays an important role in biological and biomedical research. As second-order nonlinear phenomenon, the two-photon luminescence (TPL) results from the nonlinear excitation of fluorescent molecules, while the second harmonic generation (SHG) depends on the second order nonlinear polarization, orientation, and noncentrosymmetric properties of molecules. In contrast, the linear resonance light scattering (RLS) occurs when the molecules are excited by a light beam with a wavelength close to their absorption bands. Since SHG, TPL, and RLS involve different kinds of optical processes, they might be used in parallel to provide complementary information about the structure and function of cells and tissues. Herein, we develop for the first time a multimodal optical microscopy with the capability of simultaneous SHG, TPL, and RLS imaging. We analyze theoretically and demonstrate experimentally the near-infrared irradiation-induced SHG, TPL, and RLS from the gold nanorods with nanometer spatial resolution. With the gold nanorods as the contrast agents, we further demonstrate the simultaneous SHG, TPL, and RLS imaging of A431 human epithelial skin cancer cells. This multimodal optical microscopy might provide a reliable and complementary approach for biological and biomedical research.

  15. Absorption Coefficient Imaging by Near-Field Scanning Optical Microscopy in Bacteria

    NASA Astrophysics Data System (ADS)

    de Paula, Ana M.; Chaves, Claudilene R.; Silva, Haroldo B.; Weber, Gerald

    2003-06-01

    We present a method for obtaining a position-dependent absorption coefficient from near-field scanning optical transmission microscopy. We show that the optical transmission intensity can be combined with the topography, resulting into an absorption coefficient that simplifies the analysis of different materials within a sample. The method is tested with the dye rhodamine 6G, and we show some analysis in biological samples such as bacteria Klebsiella pneumoniae and Pseudomonas aeruginosa . The calculated absorption coefficient images show important details of the bacteria, in particular for P. aeruginosa , in which membrane vesicles are clearly seen.

  16. Multifrequency-swept optical coherence microscopy for highspeed full-field tomographic vibrometry in biological tissues

    PubMed Central

    Choi, Samuel; Sato, Keita; Ota, Takeru; Nin, Fumiaki; Muramatsu, Shogo; Hibino, Hiroshi

    2017-01-01

    Because conventional laser Doppler vibrometry or Doppler optical coherence tomography require mechanical scanning probes that cannot simultaneously measure the wide-range dynamics of bio-tissues, a multifrequency-swept optical coherence microscopy with wide-field heterodyne detection technique was developed. A 1024 × 1024 × 2000 voxel volume was acquired with an axial resolution of ~1.8 μm and an acquisition speed of 2 s. Vibration measurements at 10 kHz were performed over a wide field of view. Wide-field tomographic vibration measurements of a mouse tympanic membrane are demonstrated to illustrate the applicability of this method to live animals. PMID:28270971

  17. Swept source optical coherence microscopy using a Fourier domain mode-locked laser

    NASA Astrophysics Data System (ADS)

    Huang, Shu-Wei; Aguirre, Aaron D.; Huber, Robert A.; Adler, Desmond C.; Fujimoto, James G.

    2007-05-01

    Swept source optical coherence microscopy (OCM) enables cellular resolution en face imaging as well as integration with optical coherence tomography (OCT) cross sectional imaging. A buffered Fourier domain mode-locked (FDML) laser light source provides high speed, three dimensional imaging. Image resolutions of 1.6 µm × 8 µm (transverse × axial) with a 220 µm × 220 µm field of view and sensitivity higher than 98 dB are achieved. Three dimensional cellular imaging is demonstrated in vivo in the Xenopus laevis tadpole and ex vivo in the rat kidney and human colon.

  18. Perfect optical vortex enhanced surface plasmon excitation for plasmonic structured illumination microscopy imaging

    NASA Astrophysics Data System (ADS)

    Zhang, Chonglei; Min, Changjun; Du, Luping; Yuan, X.-C.

    2016-05-01

    We propose an all-optical technique for plasmonic structured illumination microscopy (PSIM) with perfect optical vortex (POV). POV can improve the efficiency of the excitation of surface plasma and reduce the background noise of the excited fluorescence. The plasmonic standing wave patterns are excited by POV with fractional topological charges for accurate phase shift of {-2π/3, 0, and 2π/3}. The imaging resolution of less than 200 nm was produced. This PSIM technique is expected to be used as a wide field, super resolution imaging technique in dynamic biological imaging.

  19. Quantitative optical coherence microscopy for the in situ investigation of the biofilm

    NASA Astrophysics Data System (ADS)

    Meleppat, Ratheesh Kumar; Shearwood, Christopher; Keey, Seah Leong; Matham, Murukeshan Vadakke

    2016-12-01

    This paper explores the potential of optical coherence microscopy (OCM) for the in situ monitoring of biofilm growth. The quantitative imaging of the early developmental biology of a representative biofilm, Klebsiella pneumonia (KP-1), was performed using a swept source-based Fourier domain OCM system. The growth dynamics of the KP-1 biofilms and their transient response under perturbation was investigated using the enface visualization of microcolonies and their spatial localization. Furthermore, the optical density (OD) and planar density of the biofilms are calculated using an OCM technique and compared with OD and colony forming units measured using standard procedures via the sampling of the flow-cell effluent.

  20. Performance Characterization of a Switchable Acoustic Resolution and Optical Resolution Photoacoustic Microscopy System.

    PubMed

    Moothanchery, Mohesh; Pramanik, Manojit

    2017-02-12

    Photoacoustic microscopy (PAM) is a scalable bioimaging modality; one can choose low acoustic resolution with deep penetration depth or high optical resolution with shallow imaging depth. High spatial resolution and deep penetration depth is rather difficult to achieve using a single system. Here we report a switchable acoustic resolution and optical resolution photoacoustic microscopy (AR-OR-PAM) system in a single imaging system capable of both high resolution and low resolution on the same sample. Lateral resolution of 4.2 µm (with ~1.4 mm imaging depth) and lateral resolution of 45 μm (with ~7.6 mm imaging depth) was successfully demonstrated using a switchable system. In vivo blood vasculature imaging was also performed for its biological application.

  1. Vertically integrated optics for ballistic electron emission luminescence: Device and microscopy characterizations

    NASA Astrophysics Data System (ADS)

    Yi, Wei; Appelbaum, Ian; Russell, Kasey J.; Narayanamurti, Venkatesh; Schalek, Richard; Hanson, Micah P.; Gossard, Arthur C.

    2006-07-01

    By integrating a p-i-n photodiode photodetector directly into a ballistic electron emission luminescence (BEEL) heterostructure with GaAs quantum-well active region, we have obtained a photon detection efficiency of more than 10%. This is many orders of magnitude higher than conventional far-field detection scheme with the most sensitive single-photon counters, enabling BEEL microscopy in systems with no optical components. Detailed analysis shows found a parasitic bipolar injection in parallel with the desired optical coupling between the BEEL heterostructure and the integrated photodiode beyond a characteristic collector bias, which may be solved by improved device design or limiting the operating window of the collector bias. Preliminary BEEL microscopy images of a homogeneous GaAs quantum-well luminescent layer show lateral variations of photon emission correlated with the collector current injection level modulated by surface features or interface defects.

  2. Performance Characterization of a Switchable Acoustic Resolution and Optical Resolution Photoacoustic Microscopy System

    PubMed Central

    Moothanchery, Mohesh; Pramanik, Manojit

    2017-01-01

    Photoacoustic microscopy (PAM) is a scalable bioimaging modality; one can choose low acoustic resolution with deep penetration depth or high optical resolution with shallow imaging depth. High spatial resolution and deep penetration depth is rather difficult to achieve using a single system. Here we report a switchable acoustic resolution and optical resolution photoacoustic microscopy (AR-OR-PAM) system in a single imaging system capable of both high resolution and low resolution on the same sample. Lateral resolution of 4.2 µm (with ~1.4 mm imaging depth) and lateral resolution of 45 μm (with ~7.6 mm imaging depth) was successfully demonstrated using a switchable system. In vivo blood vasculature imaging was also performed for its biological application. PMID:28208676

  3. Multimodal optical workstation for simultaneous linear, nonlinear microscopy and nanomanipulation: upgrading a commercial confocal inverted microscope.

    PubMed

    Mathew, Manoj; Santos, Susana I C O; Zalvidea, Dobryna; Loza-Alvarez, Pablo

    2009-07-01

    In this work we propose and build a multimodal optical workstation that extends a commercially available confocal microscope (Nikon Confocal C1-Si) to include nonlinear/multiphoton microscopy and optical manipulation/stimulation tools such as nanosurgery. The setup allows both subsystems (confocal and nonlinear) to work independently and simultaneously. The workstation enables, for instance, nanosurgery along with simultaneous confocal and brightfield imaging. The nonlinear microscopy capabilities are added around the commercial confocal microscope by exploiting all the flexibility offered by this microscope and without need for any mechanical or electronic modification of the confocal microscope systems. As an example, the standard differential interference contrast condenser and diascopic detector in the confocal microscope are readily used as a forward detection mount for second harmonic generation imaging. The various capabilities of this workstation, as applied directly to biology, are demonstrated using the model organism Caenorhabditis elegans.

  4. Optical and confocal microscopy observations of screw dislocations in smectic-A liquid crystals.

    PubMed

    Lelidis, I; Blanc, C; Kléman, M

    2006-11-01

    We present experimental evidence of the presence of isolated screw dislocations in smectic-A liquid crystals observed by polarizing microscopy. In a wedge-shaped homeotropic cell, the edge and screw dislocations interaction gives rise to a strong-enough optical contrast and makes visible their mutual intersections at temperatures close to the smectic-A to smectic-C phase transition temperature. The nature of the defects is confirmed by confocal microscopy observations. At large scale we observe a forest of screw dislocations, perpendicular to the smectic layers, across the thickness of the cell (end-on configuration). Their density varies between 10(9) and 10(12) m-2. In situ observations of dislocations under stress, in the optical microscope, provide quantitative information about the screw-edge dislocation interactions. The latter interaction is calculated in the unharmonic approximation and it gives rise to an observed yield stress.

  5. Stochastic optical reconstruction microscopy (STORM) in comparison with stimulated emission depletion (STED) and other imaging methods.

    PubMed

    Tam, Johnny; Merino, David

    2015-11-01

    Stochastic optical reconstruction microscopy (STORM) and stimulated emission depletion (STED) microscopy are two super-resolution optical microscopy approaches that have rapidly gained popularity in recent years. Both modalities offer super-resolution imaging capabilities with the potential for imaging in multiple colors, three-dimensions, and the possibility to image in live cells. In this review, we focus on the specific advantages and disadvantages of each technique in the context of each other. STORM has been reported to achieve higher spatial resolution when compared to STED, but a lengthy acquisition may be required. STED utilizes relatively higher laser intensities, but is able to generate a super-resolution image immediately after acquisition without the need for any additional data processing. Ultimately, the choice between STORM and STED will depend not only on the specific application, but also on the users' ability to understand and optimize the various parameters ranging from sample preparation to image acquisition, which determine the quality of the final image. Stochastic optical reconstruction microscopy (STORM) and stimulated emission depletion (STED) are two super-resolution microscopy approaches that have rapidly gained popularity in recent years. STORM is based on the precise localization of a large number of individual molecules that together form a super-resolved image (bottom), whereas STED is based on the scanning of two super-imposed light sources which together allow for a super-resolved spot on the sample to be imaged (top). We discuss the specific advantages and disadvantages of each technique and explain the various parameters that affect image quality, which should be taken into consideration when planning experiments.

  6. Combination of widefield fluorescence imaging and nonlinear optical microscopy of oral epithelial neoplasia

    NASA Astrophysics Data System (ADS)

    Pal, Rahul; Edward, Kert; Brown, Tyra; Ma, Liang; Yang, Jinping; McCammon, Susan; Motamedi, Massoud; Vargas, Gracie

    2013-03-01

    Multiphoton Autofluorescence Microscopy (MPAM) and Second Harmonic Generation Microscopy (SHGM) have shown the potential for noninvasive assessment of oral precancers and cancers. We have explored a combination of these nonlinear optical microscopic imaging techniques with widefield fluorescence imaging to assess morphometry similar to that of pathologic evaluation as well as information from endogenous fluorophores, which are altered with neoplastic transformation. Widefield fluorescence revealed areas of interest corresponding to sites with precancers or early tumors, generally resulting in a decrease in green emission or increase in red emission. Subsequent microscopy revealed significant differences in morphology between normal, dysplastic/neoplastic mucosa for all layers. Combination of a widefield and a microscopic technique provides a novel approach for tissue morphometric analysis along with large area assessment of tissue autofluorescence properties.

  7. High Resolution Phase-Sensitive Magnetomotive Optical Coherence Microscopy for Tracking Magnetic Microbeads and Cellular Mechanics

    PubMed Central

    Crecea, Vasilica; Graf, Benedikt W.; Kim, Taewoo; Popescu, Gabriel; Boppart, Stephen A.

    2014-01-01

    We present a real-time multimodal near-infrared imaging technology that tracks externally induced axial motion of magnetic microbeads in single cells in culture. The integrated multimodal imaging technique consists of phase-sensitive magnetomotive optical coherence microscopy (MM-OCM) and multiphoton microscopy (MPM).MPMis utilized for the visualization of multifunctional fluorescent and magnetic microbeads, while MM-OCM detects, with nanometer-scale sensitivity, periodic displacements of the microbeads induced by the modulation of an external magnetic field. Magnetomotive signals are measured from mouse macrophages, human breast primary ductal carcinoma cells, and human breast epithelial cells in culture, and validated with full-field phase-sensitive microscopy. This methodology demonstrates the capability for imaging controlled cell dynamics and has the potential for measuring cell biomechanical properties, which are important in assessing the health and pathological state of cells. PMID:25400496

  8. Optical characters and texture maps of skin and the aging mechanism by use of multiphoton microscopy and optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Wu, Shulian; Li, Hui; Zhang, Xiaoman; Huang, Yudian; Xu, Xiaohui

    2012-03-01

    Cutaneous aging is a complicated biological process affecting different constituents of skin, which can be divided into two types: the chronological aging and the photo-aging. The two cutaneous aging processes often co-exist accompanying with each other. The effects are often overlapped including changes in epithelium and dermis. The degeneration of collagen is a major factor in dermal alteration with aging. In this study, multiphoton microscopy (MPM) with its high resolution imaging and optical coherence tomography (OCT) with its depth resolved imaging were used to study the anti-aging dermatology in vivo. It was attempted to make the optical parameter and texture feature to evaluate the process of aging skin using mathematical image processing. The links among optical parameter, spectrum and texture feature in collagen with aging process were established to uncover mechanism of aging skin.

  9. An advanced optical system for laser ablation propulsion in space

    NASA Astrophysics Data System (ADS)

    Bergstue, Grant; Fork, Richard; Reardon, Patrick

    2014-03-01

    We propose a novel space-based ablation driven propulsion engine concept utilizing transmitted energy in the form of a series of ultra-short optical pulses. Key differences are generating the pulses at the transmitting spacecraft and the safe delivery of that energy to the receiving spacecraft for propulsion. By expanding the beam diameter during transmission in space, the energy can propagate at relatively low intensity and then be refocused and redistributed to create an array of ablation sites at the receiver. The ablation array strategy allows greater control over flight dynamics and eases thermal management. Research efforts for this transmission and reception of ultra-short optical pulses include: (1) optical system design; (2) electrical system requirements; (3) thermal management; (4) structured energy transmission safety. Research has also been focused on developing an optical switch concept for the multiplexing of the ultra-short pulses. This optical switch strategy implements multiple reflectors polished into a rotating momentum wheel device to combine the pulses from different laser sources. The optical system design must minimize the thermal load on any one optical element. Initial specifications and modeling for the optical system are being produced using geometrical ray-tracing software to give a better understanding of the optical requirements. In regards to safety, we have advanced the retro-reflective beam locking strategy to include look-ahead capabilities for long propagation distances. Additional applications and missions utilizing multiplexed pulse transmission are also presented. Because the research is in early development, it provides an opportunity for new and valuable advances in the area of transmitted energy for propulsion as well as encourages joint international efforts. Researchers from different countries can cooperate in order to find constructive and safe uses of ordered pulse transmission for propulsion in future space

  10. Optical axial scanning in confocal microscopy using an electrically tunable lens.

    PubMed

    Jabbour, Joey M; Malik, Bilal H; Olsovsky, Cory; Cuenca, Rodrigo; Cheng, Shuna; Jo, Javier A; Cheng, Yi-Shing Lisa; Wright, John M; Maitland, Kristen C

    2014-02-01

    This paper presents the use and characterization of an electrically focus tunable lens to perform axial scanning in a confocal microscope. Lateral and axial resolution are characterized over a >250 µm axial scan range. Confocal microscopy using optical axial scanning is demonstrated in epithelial tissue and compared to traditional stage scanning. By enabling rapid axial scanning, minimizing motion artifacts, and reducing mechanical complexity, this technique has potential to enhance in vivo three-dimensional imaging in confocal endomicroscopy.

  11. Digital polarization holography advancing 4G optics (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    De Sio, Luciano; Roberts, David E.; Tabiryan, Nelson V.; Steeves, Diane M.; Kimball, Brian R.

    2016-09-01

    The fourth generation optics (4G optics) enables the realization of novel optical components (lenses, gratings, vector vortices, etc.) by patterning the optical axis orientation in the plane of an anisotropic film. Such components exhibit near 100% diffraction efficiency for wavelengths meeting half-wave retardation condition. In this framework, we have advanced a step-forward by realizing different diffractive waveplates (DWs) with arbitrary spatial patterns of the optical axis orientation by exploiting the capability of a Digital Spatial Light Polarization Converter (DSLPC). The DSLPC is based on a reflective, high resolution Spatial Light Modulator (SLM) combined with an "ad hoc" optical setup. The most attractive feature of the use of a DSLPC for photoalignment is that the orientation of the alignment layer, and therefore of the fabricated liquid crystal (LC) or liquid crystal polymer (LCP) DWs, can be specified on a pixel-by-pixel basis. By varying the optical magnification or de-magnification between the SLM and the alignment layer, the spatial resolution of the photoaligned layer can be adjusted to be optimal for each application. We show that with a simple "click" it is possible to record different high resolution optical components as well as arbitrary patterns ranging from lenses to invisible and even dual labels.

  12. Optically sectioned in vivo imaging with speckle illumination HiLo microscopy

    NASA Astrophysics Data System (ADS)

    Lim, Daryl; Ford, Tim N.; Chu, Kengyeh K.; Mertz, Jerome

    2011-01-01

    We present a simple wide-field imaging technique, called HiLo microscopy, that is capable of producing optically sectioned images in real time, comparable in quality to confocal laser scanning microscopy. The technique is based on the fusion of two raw images, one acquired with speckle illumination and another with standard uniform illumination. The fusion can be numerically adjusted, using a single parameter, to produce optically sectioned images of varying thicknesses with the same raw data. Direct comparison between our HiLo microscope and a commercial confocal laser scanning microscope is made on the basis of sectioning strength and imaging performance. Specifically, we show that HiLo and confocal 3-D imaging of a GFP-labeled mouse brain hippocampus are comparable in quality. Moreover, HiLo microscopy is capable of faster, near video rate imaging over larger fields of view than attainable with standard confocal microscopes. The goal of this paper is to advertise the simplicity, robustness, and versatility of HiLo microscopy, which we highlight with in vivo imaging of common model organisms including planaria, C. elegans, and zebrafish.

  13. Optical tweezers and multiphoton microscopies integrated photonic tool for mechanical and biochemical cell processes studies

    NASA Astrophysics Data System (ADS)

    de Thomaz, A. A.; Faustino, W. M.; Fontes, A.; Fernandes, H. P.; Barjas-Castro, M. d. L.; Metze, K.; Giorgio, S.; Barbosa, L. C.; Cesar, C. L.

    2007-09-01

    The research in biomedical photonics is clearly evolving in the direction of the understanding of biological processes at the cell level. The spatial resolution to accomplish this task practically requires photonics tools. However, an integration of different photonic tools and a multimodal and functional approach will be necessary to access the mechanical and biochemical cell processes. This way we can observe mechanicaly triggered biochemical events or biochemicaly triggered mechanical events, or even observe simultaneously mechanical and biochemical events triggered by other means, e.g. electricaly. One great advantage of the photonic tools is its easiness for integration. Therefore, we developed such integrated tool by incorporating single and double Optical Tweezers with Confocal Single and Multiphoton Microscopies. This system can perform 2-photon excited fluorescence and Second Harmonic Generation microscopies together with optical manipulations. It also can acquire Fluorescence and SHG spectra of specific spots. Force, elasticity and viscosity measurements of stretched membranes can be followed by real time confocal microscopies. Also opticaly trapped living protozoas, such as leishmania amazonensis. Integration with CARS microscopy is under way. We will show several examples of the use of such integrated instrument and its potential to observe mechanical and biochemical processes at cell level.

  14. Identification and evaluation on the phagocytic function of human neutrophils in diabetic patients by optical microscopy with cellular monolayer techniques and electron microscopy

    NASA Astrophysics Data System (ADS)

    Yu, Ye-Rong; Liang, Jing-Zhong

    1995-01-01

    A comparative study on phagocytosis of P. Aeruginosa by human neutrophils in diabetic patients and healthy volunteers was carried out by means of the monolayer of neutrophils in optical microscopy and ultrastructural observation in electronic microscopy. The results demonstrated that the level of phagocytosis in diabetics is lower than health people. The impairment in phagocytosis of neutrophils may be the important cause of severe and repeated infection in diabetic patients.

  15. Gold-copper nanostars as photo-thermal agents: synthesis and advanced electron microscopy characterization

    NASA Astrophysics Data System (ADS)

    Bazán-Díaz, Lourdes; Mendoza-Cruz, Rubén; Velázquez-Salazar, J. Jesús; Plascencia-Villa, Germán; Romeu, David; Reyes-Gasga, José; Herrera-Becerra, Raúl; José-Yacamán, Miguel; Guisbiers, Grégory

    2015-12-01

    Nanoalloys have emerged as multi-functional nanoparticles with applications in biomedicine and catalysis. This work reports the efficient production and the advanced transmission electron microscopy characterization of gold-copper pentagonal nanostars. The morphology of the branches is controlled by the adequate choice of the capping agent. When oleylamine is used rounded nanostars are produced, while pointed nanostars are obtained by using hexadecylamine. Both types of nanostars were proved to be thermally stable and could therefore be used as therapeutic agents in photo-thermal therapies as confirmed by the near-infrared absorption spectra.Nanoalloys have emerged as multi-functional nanoparticles with applications in biomedicine and catalysis. This work reports the efficient production and the advanced transmission electron microscopy characterization of gold-copper pentagonal nanostars. The morphology of the branches is controlled by the adequate choice of the capping agent. When oleylamine is used rounded nanostars are produced, while pointed nanostars are obtained by using hexadecylamine. Both types of nanostars were proved to be thermally stable and could therefore be used as therapeutic agents in photo-thermal therapies as confirmed by the near-infrared absorption spectra. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06491k

  16. Advanced Optical Burst Switched Network Concepts

    NASA Astrophysics Data System (ADS)

    Nejabati, Reza; Aracil, Javier; Castoldi, Piero; de Leenheer, Marc; Simeonidou, Dimitra; Valcarenghi, Luca; Zervas, Georgios; Wu, Jian

    In recent years, as the bandwidth and the speed of networks have increased significantly, a new generation of network-based applications using the concept of distributed computing and collaborative services is emerging (e.g., Grid computing applications). The use of the available fiber and DWDM infrastructure for these applications is a logical choice offering huge amounts of cheap bandwidth and ensuring global reach of computing resources [230]. Currently, there is a great deal of interest in deploying optical circuit (wavelength) switched network infrastructure for distributed computing applications that require long-lived wavelength paths and address the specific needs of a small number of well-known users. Typical users are particle physicists who, due to their international collaborations and experiments, generate enormous amounts of data (Petabytes per year). These users require a network infrastructures that can support processing and analysis of large datasets through globally distributed computing resources [230]. However, providing wavelength granularity bandwidth services is not an efficient and scalable solution for applications and services that address a wider base of user communities with different traffic profiles and connectivity requirements. Examples of such applications may be: scientific collaboration in smaller scale (e.g., bioinformatics, environmental research), distributed virtual laboratories (e.g., remote instrumentation), e-health, national security and defense, personalized learning environments and digital libraries, evolving broadband user services (i.e., high resolution home video editing, real-time rendering, high definition interactive TV). As a specific example, in e-health services and in particular mammography applications due to the size and quantity of images produced by remote mammography, stringent network requirements are necessary. Initial calculations have shown that for 100 patients to be screened remotely, the network

  17. Lithographic measurement of EUV flare in the 0.3-NA Micro ExposureTool optic at the Advanced Light Source

    SciTech Connect

    Cain, Jason P.; Naulleau, Patrick; Spanos, Costas J.

    2005-01-01

    The level of flare present in a 0.3-NA EUV optic (the MET optic) at the Advanced Light Source at Lawrence Berkeley National Laboratory is measured using a lithographic method. Photoresist behavior at high exposure doses makes analysis difficult. Flare measurement analysis under scanning electron microscopy (SEM) and optical microscopy is compared, and optical microscopy is found to be a more reliable technique. In addition, the measured results are compared with predictions based on surface roughness measurement of the MET optical elements. When the fields in the exposure matrix are spaced far enough apart to avoid influence from surrounding fields and the data is corrected for imperfect mask contrast and aerial image proximity effects, the results match predicted values quite well. The amount of flare present in this optic ranges from 4.7% for 2 {micro}m features to 6.8% for 500 nm features.

  18. Individual Particle Analysis of Ambient PM 2.5 Using Advanced Electron Microscopy Techniques

    SciTech Connect

    Gerald J. Keeler; Masako Morishita

    2006-12-31

    The overall goal of this project was to demonstrate a combination of advanced electron microscopy techniques that can be effectively used to identify and characterize individual particles and their sources. Specific techniques to be used include high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM energy dispersive X-ray spectrometry (EDX), and energy-filtered TEM (EFTEM). A series of ambient PM{sub 2.5} samples were collected in communities in southwestern Detroit, MI (close to multiple combustion sources) and Steubenville, OH (close to several coal fired utility boilers). High-resolution TEM (HRTEM) -imaging showed a series of nano-metal particles including transition metals and elemental composition of individual particles in detail. Submicron and nano-particles with Al, Fe, Ti, Ca, U, V, Cr, Si, Ba, Mn, Ni, K and S were observed and characterized from the samples. Among the identified nano-particles, combinations of Al, Fe, Si, Ca and Ti nano-particles embedded in carbonaceous particles were observed most frequently. These particles showed very similar characteristics of ultrafine coal fly ash particles that were previously reported. By utilizing HAADF-STEM, STEM-EDX, and EF-TEM, this investigation was able to gain information on the size, morphology, structure, and elemental composition of individual nano-particles collected in Detroit and Steubenville. The results showed that the contributions of local combustion sources - including coal fired utilities - to ultrafine particle levels were significant. Although this combination of advanced electron microscopy techniques by itself can not identify source categories, these techniques can be utilized as complementary analytical tools that are capable of providing detailed information on individual particles.

  19. Advanced materials and techniques for fibre-optic sensing

    NASA Astrophysics Data System (ADS)

    Henderson, Philip J.

    2014-06-01

    Fibre-optic monitoring systems came of age in about 1999 upon the emergence of the world's first significant commercialising company - a spin-out from the UK's collaborative MAST project. By using embedded fibre-optic technology, the MAST project successfully measured transient strain within high-performance composite yacht masts. Since then, applications have extended from smart composites into civil engineering, energy, military, aerospace, medicine and other sectors. Fibre-optic sensors come in various forms, and may be subject to embedment, retrofitting, and remote interrogation. The unique challenges presented by each implementation require careful scrutiny before widespread adoption can take place. Accordingly, various aspects of design and reliability are discussed spanning a range of representative technologies that include resonant microsilicon structures, MEMS, Bragg gratings, advanced forms of spectroscopy, and modern trends in nanotechnology. Keywords: Fibre-optic sensors, fibre Bragg gratings, MEMS, MOEMS, nanotechnology, plasmon.

  20. Simple fiber-optic confocal microscopy with nanoscale depth resolution beyond the diffraction barrier.

    PubMed

    Ilev, Ilko; Waynant, Ronald; Gannot, Israel; Gandjbakhche, Amir

    2007-09-01

    A novel fiber-optic confocal approach for ultrahigh depth-resolution (microscopy beyond the diffraction barrier in the subwavelength nanometric range below 200 nm is presented. The key idea is based on a simple fiber-optic confocal microscope approach that is compatible with a differential confocal microscope technique. To improve the dynamic range of the resolving laser power and to achieve a high resolution in the nanometric range, we have designed a simple apertureless reflection confocal microscope with a highly sensitive single-mode-fiber confocal output. The fiber-optic design is an effective alternative to conventional pinhole-based confocal systems and offers a number of advantages in terms of spatial resolution, flexibility, miniaturization, and scanning potential. Furthermore, the design is compatible with the differential confocal pinhole microscope based on the use of the sharp diffraction-free slope of the axial confocal response curve rather than the area around the maximum of that curve. Combining the advantages of ultrahigh-resolution fiber-optic confocal microscopy, we can work beyond the diffraction barrier in the subwavelength (below 200 nm) nanometric range exploiting confocal nanobioimaging of single cell and intracellular analytes.

  1. Sub-cellular resolution imaging with Gabor domain optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Meemon, P.; Lee, K. S.; Murali, S.; Kaya, I.; Thompson, K. P.; Rolland, J. P.

    2010-02-01

    Optical Coherence Microscopy (OCM) utilizes a high NA microscope objective in the sample arm to achieve an axially and laterally high resolution OCT image. An increase in NA, however, leads to a dramatically decreased depth of focus (DOF), and hence shortens the imaging depth range so that high lateral resolution is maintained only within a small depth region around the focal plane. One solution to increase the depth of imaging while keeping a high lateral resolution is dynamic-focusing. Utilizing the voltage controlled refocus capability of a liquid lens, we have recently presented a solution for invariant high resolution imaging using the liquid lens embedded within a fixed optics hand-held custom microscope designed specifically for optical imaging systems using a broadband light source at 800 nm center wavelength. Subsequently, we have developed a Gabor-Domain Optical Coherence Microscopy (GD-OCM) that utilizes the high speed imaging of spectral domain OCT, the high lateral resolution of OCM, and the ability of real time refocusing of our custom design variable focus objective. In this paper we demonstrate in detail how portions of the infocus cross-sectional images can be extracted and fused to form an invariant lateral resolution image with multiple crosssectional images acquired corresponding to a discrete refocusing step along depth enabled by the varifocal probe. We demonstrate sub-cellular resolution imaging of an African frog tadpole (Xenopus Laevis) taken from a 500 μm x 500 μm cross-section.

  2. Scattering-type scanning near-field optical microscopy with reconstruction of vertical interaction

    NASA Astrophysics Data System (ADS)

    Wang, Le; Xu, Xiaoji G.

    2015-11-01

    Scattering-type scanning near-field optical microscopy provides access to super-resolution spectroscopic imaging of the surfaces of a variety of materials and nanostructures. In addition to chemical identification, it enables observations of nano-optical phenomena, such as mid-infrared plasmons in graphene and phonon polaritons in boron nitride. Despite the high lateral spatial resolution, scattering-type near-field optical microscopy is not able to provide characteristics of near-field responses in the vertical dimension, normal to the sample surface. Here, we present an accurate and fast reconstruction method to obtain vertical characteristics of near-field interactions. For its first application, we investigated the bound electromagnetic field component of surface phonon polaritons on the surface of boron nitride nanotubes and found that it decays within 20 nm with a considerable phase change in the near-field signal. The method is expected to provide characterization of the vertical field distribution of a wide range of nano-optical materials and structures.

  3. Optical coherence microscopy for deep tissue imaging of the cerebral cortex with intrinsic contrast

    PubMed Central

    Srinivasan, Vivek J.; Radhakrishnan, Harsha; Jiang, James Y.; Barry, Scott; Cable, Alex E.

    2012-01-01

    In vivo optical microscopic imaging techniques have recently emerged as important tools for the study of neurobiological development and pathophysiology. In particular, two-photon microscopy has proved to be a robust and highly flexible method for in vivo imaging in highly scattering tissue. However, two-photon imaging typically requires extrinsic dyes or contrast agents, and imaging depths are limited to a few hundred microns. Here we demonstrate Optical Coherence Microscopy (OCM) for in vivo imaging of neuronal cell bodies and cortical myelination up to depths of ~1.3 mm in the rat neocortex. Imaging does not require the administration of exogenous dyes or contrast agents, and is achieved through intrinsic scattering contrast and image processing alone. Furthermore, using OCM we demonstrate in vivo, quantitative measurements of optical properties (index of refraction and attenuation coefficient) in the cortex, and correlate these properties with laminar cellular architecture determined from the images. Lastly, we show that OCM enables direct visualization of cellular changes during cell depolarization and may therefore provide novel optical markers of cell viability. PMID:22330462

  4. Investigating the transverse optical structure of spider silk micro-fibers using quantitative optical microscopy

    NASA Astrophysics Data System (ADS)

    Little, Douglas J.; Kane, Deb M.

    2016-10-01

    The transverse optical structure of two orb-weaver (family Araneidae) spider dragline silks was investigated using a variant of the inverse-scattering technique. Immersing the silks in a closely refractive index-matched liquid, the minimum achievable image contrast was greater than expected for an optically homogeneous silk, given what is currently known about the optical absorption of these silks. This "excess contrast" indicated the presence of transverse optical structure within the spider silk. Applying electromagnetic scattering theory to a transparent double cylinder, the minimum achievable irradiance contrast for the Plebs eburnus and Argiope keyserlingi dragline silks was determined to be consistent with step index refractive index contrasts of 1-4×10-4 and 6-7×10-4, respectively, supposing outer-layer thicknesses consistent with previous TEM studies (50 nm and 100 nm, respectively). The possibility of graded index refractive index contrasts within the spider silks is also discussed. This is the strongest evidence, to date, that there is a refractive index contrast associated with the layered morphology of spider silks and/or variation of proportion of nanocrystalline components within the spider silk structure. The method is more generally applicable to optical micro-fibers, including those with refractive index variations on a sub-wavelength scale.

  5. Investigating the transverse optical structure of spider silk micro-fibers using quantitative optical microscopy

    NASA Astrophysics Data System (ADS)

    Little, Douglas J.; Kane, Deb M.

    2017-01-01

    The transverse optical structure of two orb-weaver (family Araneidae) spider dragline silks was investigated using a variant of the inverse-scattering technique. Immersing the silks in a closely refractive index-matched liquid, the minimum achievable image contrast was greater than expected for an optically homogeneous silk, given what is currently known about the optical absorption of these silks. This "excess contrast" indicated the presence of transverse optical structure within the spider silk. Applying electromagnetic scattering theory to a transparent double cylinder, the minimum achievable irradiance contrast for the Plebs eburnus and Argiope keyserlingi dragline silks was determined to be consistent with step index refractive index contrasts of 1-4×10-4 and 6-7×10-4, respectively, supposing outer-layer thicknesses consistent with previous TEM studies (50 nm and 100 nm, respectively). The possibility of graded index refractive index contrasts within the spider silks is also discussed. This is the strongest evidence, to date, that there is a refractive index contrast associated with the layered morphology of spider silks and/or variation of proportion of nanocrystalline components within the spider silk structure. The method is more generally applicable to optical micro-fibers, including those with refractive index variations on a sub-wavelength scale.

  6. Optical spatial solitons: historical overview and recent advances.

    PubMed

    Chen, Zhigang; Segev, Mordechai; Christodoulides, Demetrios N

    2012-08-01

    Solitons, nonlinear self-trapped wavepackets, have been extensively studied in many and diverse branches of physics such as optics, plasmas, condensed matter physics, fluid mechanics, particle physics and even astrophysics. Interestingly, over the past two decades, the field of solitons and related nonlinear phenomena has been substantially advanced and enriched by research and discoveries in nonlinear optics. While optical solitons have been vigorously investigated in both spatial and temporal domains, it is now fair to say that much soliton research has been mainly driven by the work on optical spatial solitons. This is partly due to the fact that although temporal solitons as realized in fiber optic systems are fundamentally one-dimensional entities, the high dimensionality associated with their spatial counterparts has opened up altogether new scientific possibilities in soliton research. Another reason is related to the response time of the nonlinearity. Unlike temporal optical solitons, spatial solitons have been realized by employing a variety of noninstantaneous nonlinearities, ranging from the nonlinearities in photorefractive materials and liquid crystals to the nonlinearities mediated by the thermal effect, thermophoresis and the gradient force in colloidal suspensions. Such a diversity of nonlinear effects has given rise to numerous soliton phenomena that could otherwise not be envisioned, because for decades scientists were of the mindset that solitons must strictly be the exact solutions of the cubic nonlinear Schrödinger equation as established for ideal Kerr nonlinear media. As such, the discoveries of optical spatial solitons in different systems and associated new phenomena have stimulated broad interest in soliton research. In particular, the study of incoherent solitons and discrete spatial solitons in optical periodic media not only led to advances in our understanding of fundamental processes in nonlinear optics and photonics, but also had a

  7. Volumetric optical mapping in early embryonic hearts using light-sheet microscopy

    PubMed Central

    Ma, Pei; Chan, Dennis C.; Gu, Shi; Watanabe, Michiko; Jenkins, Michael W.; Rollins, Andrew M.

    2016-01-01

    Optical mapping (OM) of electrical activity using voltage-sensitive fluorescent dyes is a powerful tool for the investigation of embryonic cardiac electrophysiology. However, because conventional OM integrates the signal in depth and projects it to a two-dimensional plane, information acquired is incomplete and dependent upon the orientation of the sample. This complicates interpretation of data, especially when comparing one heart to another. To overcome this limitation, we present volumetric OM using light-sheet microscopy, which enables high-speed capture of optically sectioned slices. Voltage-sensitive fluorescence images from multiple planes across entire early embryonic quail hearts were acquired, and complete, orientation-independent, four-dimensional maps of transmembrane potential are demonstrated. Volumetric OM data were collected while using optical pacing to control the heart rate, paving the way for physiological measurements and precise manipulation of the heartbeat in the future. PMID:28018729

  8. Field of view advantage of conjugate adaptive optics in microscopy applications.

    PubMed

    Mertz, Jerome; Paudel, Hari; Bifano, Thomas G

    2015-04-10

    The imaging performance of an optical microscope can be degraded by sample-induced aberrations. A general strategy to undo the effect of these aberrations is to apply wavefront correction with a deformable mirror (DM). In most cases the DM is placed conjugate to the microscope pupil, called pupil adaptive optics (AO). When the aberrations are spatially variant an alternative configuration involves placing the DM conjugate to the main source of aberrations, called conjugate AO. We provide a theoretical and experimental comparison of both configurations for the simplified case where spatially variant aberrations are produced by a well-defined phase screen. We pay particular attention to the resulting correction field of view (FOV). Conjugate AO is found to provide a significant FOV advantage. While this result is well known in the astronomical community, our goal here is to recast it specifically for the optical microscopy community.

  9. Three-dimensional deep sub-wavelength defect detection using λ = 193 nm optical microscopy.

    PubMed

    Barnes, Bryan M; Sohn, Martin Y; Goasmat, Francois; Zhou, Hui; Vladár, András E; Silver, Richard M; Arceo, Abraham

    2013-11-04

    Optical microscopy is sensitive both to arrays of nanoscale features and to their imperfections. Optimizing scattered electromagnetic field intensities from deep sub-wavelength nanometer scale structures represents an important element of optical metrology. Current, well-established optical methods used to identify defects in semiconductor patterning are in jeopardy by upcoming sub-20 nm device dimensions. A novel volumetric analysis for processing focus-resolved images of defects is presented using simulated and experimental examples. This new method allows defects as narrow as (16 ± 2) nm (k = 1) to be revealed using 193 nm light with focus and illumination conditions optimized for three-dimensional data analysis. Quantitative metrics to compare two-dimensional and three-dimensional imaging indicate possible fourfold improvements in sensitivity using these methods.

  10. All-optical photoacoustic microscopy based on plasmonic detection of broadband ultrasound

    NASA Astrophysics Data System (ADS)

    Wang, Tianxiong; Cao, Rui; Ning, Bo; Dixon, Adam J.; Hossack, John A.; Klibanov, Alexander L.; Zhou, Qifa; Wang, Anbo; Hu, Song

    2015-10-01

    We report on an implementation of all-optical photoacoustic microscopy (PAM), which capitalizes on the effect of surface plasmon resonance (SPR) for optical detection of ultrasound. The SPR sensor in our all-optical PAM shows, experimentally, a linear response to the acoustic pressure from 5.2 kPa to 2.1 MPa, an ultra-flat frequency response (±0.7 dB) from 680 kHz to 126 MHz, and a noise-equivalent pressure sensitivity of 3.3 kPa. With the broadband ultrasonic detection, our SPR-PAM has achieved high spatial resolution with relatively low anisotropy (i.e., 2.0 μm laterally and 8.4 μm axially). Three-dimensional high-resolution imaging of a single melanoma cell is demonstrated.

  11. Extended-focus optical coherence microscopy for high-resolution imaging of the murine brain

    PubMed Central

    Tamborski, Szymon; Lyu, Hong Chou; Dolezyczek, Hubert; Malinowska, Monika; Wilczynski, Grzegorz; Szlag, Daniel; Lasser, Theo; Wojtkowski, Maciej; Szkulmowski, Maciej

    2016-01-01

    We propose a new method and optical instrumentation for mouse brain imaging based on extended-focus optical coherence microscopy. This in vivo imaging technique allows the evaluation of the cytoarchitecture at cellular level and the circulation system dynamics in three dimensions. This minimally invasive and non-contact approach is performed without the application of contrasting agents. The optical design achieved a resolution of 2.2 μm over a distance of 800 μm, which was sufficient to obtain a detailed three-dimensional image of a wild-type mouse’s brain down to the layer III of the cortex. Intrinsically contrasted microvessels and structures similar to the bodies of neurons were distinguishable. PMID:27895982

  12. An optical scan-calibration system in scanning near-field optical microscopy

    NASA Astrophysics Data System (ADS)

    Wu, Yunliang; Zhang, Hao; Wang, Keyi

    2009-11-01

    Scanning Probe Microscopes(SPM) use piezoelectric actuators to generate the scans. But the nonlinearities inherent in the piezoelectric actuators limit the usefulness of the instruments in precision metrology. This paper describes a simple optical beam displacement sensor that is used to accurately measure the (x,y) position of a piezoelectric tube scanner used in Scanning Near-field Optical Microscope(SNOM). As the nonlinearities is too complex to make up a simple math model, this paper use the Artificial neural network to Calibrate the nonlinearities.

  13. EDITORIAL: Special issue on optical neural engineering: advances in optical stimulation technology Special issue on optical neural engineering: advances in optical stimulation technology

    NASA Astrophysics Data System (ADS)

    Shoham, Shy; Deisseroth, Karl

    2010-08-01

    a single spine, with two-photon uncaging) and in rapid, flexible spatial-temporal patterns [10-14]. Nevertheless, current technology generally requires damaging doses of UV or violet illumination and the continuous re-introduction of the caged compound, which, despite interest, makes for a difficult transition beyond in vitro preparations. Thus, the tremendous progress in the in vivo application of photo-stimulation tools over the past five years has been largely facilitated by two 'exciting' new photo-stimulation technologies: photo-biological stimulation of a rapidly increasing arsenal of light-sensitive ion channels and pumps ('optogenetic' probes[15-18]) and direct photo-thermal stimulation of neural tissue with an IR laser [19-21]. The Journal of Neural Engineering has dedicated a special section in this issue to highlight advances in optical stimulation technology, which includes original peer-reviewed contributions dealing with the design of modern optical systems for spatial-temporal control of optical excitation patterns and with the biophysics of neural-thermal interaction mediated by electromagnetic waves. The paper by Nikolenko, Peterka and Yuste [22] presents a compact design of a microscope-photo-stimulator based on a transmissive phase-modulating spatial-light modulator (SLM). Computer-generated holographic photo-stimulation using SLMs [12-14, 23] allows the efficient parallel projection of intense sparse patterns of light, and the welcome development of compact, user-friendly systems will likely reduce the barrier to its widespread adoption. The paper by Losavio et al [24] presents the design and functional characteristics of their acousto-optical deflector (AOD) systems for studying spatial-temporal dendritic integration in single neurons in vitro. Both single-photon (UV) and two-photon (femtosecond pulsed IR) AOD uncaging systems are described in detail. The paper presents an excellent overview of the current state of the art and limitations of

  14. Advances in DOE modeling and optical performance for SMO applications

    NASA Astrophysics Data System (ADS)

    Carriere, James; Stack, Jared; Childers, John; Welch, Kevin; Himel, Marc D.

    2010-04-01

    The introduction of source mask optimization (SMO) to the design process addresses an urgent need for the 32nm node and beyond as alternative lithography approaches continue to push out. To take full advantage of SMO routines, an understanding of the characteristic properties of diffractive optical elements (DOEs) is required. Greater flexibility in the DOE output is needed to optimize lithographic process windows. In addition, new and tighter constraints on the DOEs used for off-axis illumination (OAI) are being introduced to precisely predict, control and reduce the effects of pole imbalance and stray light on the CD budget. We present recent advancements in the modeling and optical performance of these DOEs.

  15. Two-axis water-immersible microscanning mirror for scanning optics and acoustic microscopy

    NASA Astrophysics Data System (ADS)

    Xu, Song; Zou, Jun

    2016-10-01

    Fast multiaxis scanning is useful for not only optical but also acoustic microscopic imaging. Although they have been used for optical scanning, the application of (MEMS) scanning mirrors in acoustic microscopy is still very limited due to their small mirror plate size, and more importantly, inability to operate in liquids (as ultrasound coupling media). A microfabricated two-axis water-immersible scanning mirror for optical and acoustic microscopy is reported. It has an optical and acoustically reflective mirror plate (6 mm×4 mm) to provide numerical aperture for ultrasound beam steering. Electromagnetic and mechanical analysis and simulation were conducted to estimate the mechanical tilting angle and resonance frequency of both fast and slow axes, which matches well with the measurement results. The fast axis has a resonant frequency of 320 Hz in air and 220 Hz in water, which is more than 10 times higher than that of the slow axis (24 Hz in air and 14 Hz in water). Under a 100-mA driving current, the scanning angles of the fast axis reached ±9.5 deg in both air and water at the resonance frequency, respectively. The scanning angles of the slow axis reached ±15 deg in air and ±12.5 deg in water at resonant frequencies, respectively. Raster scanning of a collimated laser beam was achieved by driving both axes simultaneously close to their own resonance frequencies. The feasibility of using the two-axis water-immersible scanning mirror in scanning acoustic microscopy was also demonstrated.

  16. Catheters: instrumental advancements in biomedical applications of optical fibers.

    PubMed

    de Lima, Carlos J; Moreira, Leonardo M; Lyon, Juliana P; Villaverde, Antonio B; Pacheco, Marcos T T

    2009-07-01

    This review is focused on the advancements in biomedical engineering regarding the elaboration of new prototypes of optical fiber catheters to be applied in spectroscopic analysis, such as Raman and fluorescence spectroscopy. Our group has contributed to the development of new prototypes with interesting properties, such as side-viewing signal excitation and collection, distal tip with bending control, and Raman scattering minimization from the optical fiber. In addition, several groups have contributed to other new catheter-improving properties of this spectroscopic device. However, a relatively small number of studies has been published in the literature, due to industrial interest in this interdisciplinary and multidisciplinary area. To our knowledge, no review that has focused on the applications of catheters to several modes of spectroscopy has been published. In this work we revised this topic, analyzing the advancements and limitations of the recent biomedical catheters.

  17. Sub‐40 fs, 1060‐nm Yb‐fiber laser enhances penetration depth in nonlinear optical microscopy of human skin

    PubMed Central

    Balu, Mihaela; Saytashev, Ilyas; Hou, Jue; Dantus, Marcos; Tromberg, Bruce J.

    2015-01-01

    Abstract. Advancing the practical utility of nonlinear optical microscopy requires continued improvement in imaging depth and contrast. We evaluated second‐harmonic generation (SHG) and third‐harmonic generation images from ex vivo human skin and showed that a sub‐40 fs, 1060‐nm Yb‐fiber laser can enhance SHG penetration depth by up to 80% compared to a >100  fs, 800 nm Ti:sapphire source. These results demonstrate the potential of fiber‐based laser systems to address a key performance limitation related to nonlinear optical microscopy (NLOM) technology while providing a low‐barrier‐to‐access alternative to Ti:sapphire sources that could help accelerate the movement of NLOM into clinical practice. PMID:26641198

  18. Advanced Laser Chemical Processing For Microelectronics and Integrated Optics

    DTIC Science & Technology

    1992-08-15

    Barbara, CA (June 25-27, 1990). 15. R.M. Osgood, Jr., " Laser - Fabrication for Integrated Electronics and Optics," OITDA Conference, Tokyo, Japan, (July 5...Society Meeting, Boston, MA, November 26 - December 3, 1990. 20. R.M. Osgood, Jr., "Advances in Laser Fabrication for Solid-State Electronics and...Thin, Excimer Laser-Deposited Cd Interlayers," J. Elec. Mat. 12, 1239 (July, 1990). 14. R.M. Osgood, Jr., " Laser - Fabrication for Solid State

  19. Finite-difference time-domain-based optical microscopy simulation of dispersive media facilitates the development of optical imaging techniques

    NASA Astrophysics Data System (ADS)

    Zhang, Di; Capoglu, Ilker; Li, Yue; Cherkezyan, Lusik; Chandler, John; Spicer, Graham; Subramanian, Hariharan; Taflove, Allen; Backman, Vadim

    2016-06-01

    Combining finite-difference time-domain (FDTD) methods and modeling of optical microscopy modalities, we previously developed an open-source software package called Angora, which is essentially a "microscope in a computer." However, the samples being simulated were limited to nondispersive media. Since media dispersions are common in biological samples (such as cells with staining and metallic biomarkers), we have further developed a module in Angora to simulate samples having complicated dispersion properties, thereby allowing the synthesis of microscope images of most biological samples. We first describe a method to integrate media dispersion into FDTD, and we validate the corresponding Angora dispersion module by applying Mie theory, as well as by experimentally imaging gold microspheres. Then, we demonstrate how Angora can facilitate the development of optical imaging techniques with a case study.

  20. 76 FR 12144 - Advanced Optics Electronics, Inc.; Order of Suspension of Trading

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-04

    ... COMMISSION Advanced Optics Electronics, Inc.; Order of Suspension of Trading March 2, 2011. It appears to the... securities of Advanced Optics Electronics, Inc. because it has not filed any periodic reports since the... of investors require a suspension of trading in Advanced Optics Electronics, Inc. Therefore, it...

  1. Advanced fluorescence microscopy methods for the real-time study of transcription and chromatin dynamics

    PubMed Central

    Annibale, Paolo; Gratton, Enrico

    2014-01-01

    In this contribution we provide an overview of the recent advances allowed by the use of fluorescence microscopy methods in the study of transcriptional processes and their interplay with the chromatin architecture in living cells. Although the use of fluorophores to label nucleic acids dates back at least to about half a century ago,1 two recent breakthroughs have effectively opened the way to use fluorescence routinely for specific and quantitative probing of chromatin organization and transcriptional activity in living cells: namely, the possibility of labeling first the chromatin loci and then the mRNA synthesized from a gene using fluorescent proteins. In this contribution we focus on methods that can probe rapid dynamic processes by analyzing fast fluorescence fluctuations. PMID:25764219

  2. Advances in quantitative nanoscale subsurface imaging by mode-synthesizing atomic force microscopy

    SciTech Connect

    Vitry, P.; Bourillot, E.; Plassard, C.; Lacroute, Y.; Lesniewska, E.; Tetard, L.

    2014-08-04

    This paper reports on advances toward quantitative non-destructive nanoscale subsurface investigation of a nanofabricated sample based on mode synthesizing atomic force microscopy with heterodyne detection, addressing the need to correlate the role of actuation frequencies of the probe f{sub p} and the sample f{sub s} with depth resolution for 3D tomography reconstruction. Here, by developing a simple model and validating the approach experimentally through the study of the nanofabricated calibration depth samples consisting of buried metallic patterns, we demonstrate avenues for quantitative nanoscale subsurface imaging. Our findings enable the reconstruction of the sample depth profile and allow high fidelity resolution of the buried nanostructures. Non-destructive quantitative nanoscale subsurface imaging offers great promise in the study of the structures and properties of complex systems at the nanoscale.

  3. Advances in cryogenic transmission electron microscopy for the characterization of dynamic self-assembling nanostructures

    PubMed Central

    Newcomb, Christina J.; Moyer, Tyson J.; Lee, Sungsoo S.; Stupp, Samuel I.

    2012-01-01

    Elucidating the structural information of nanoscale materials in their solvent-exposed state is crucial, as a result, cryogenic transmission electron microscopy (cryo-TEM) has become an increasingly popular technique in the materials science, chemistry, and biology communities. Cryo-TEM provides a method to directly visualize the specimen structure in a solution-state through a thin film of vitrified solvent. This technique complements X-ray, neutron, and light scattering methods that probe the statistical average of all species present; furthermore, cryo-TEM can be used to observe changes in structure over time. In the area of self-assembly, this tool has been particularly powerful for the characterization of natural and synthetic small molecule assemblies, as well as hybrid organic–inorganic composites. In this review, we discuss recent advances in cryogenic TEM in the context of self-assembling systems with emphasis on characterization of transitions observed in response to external stimuli. PMID:23204913

  4. Advances in cryogenic transmission electron microscopy for the characterization of dynamic self-assembling nanostructures.

    PubMed

    Newcomb, Christina J; Moyer, Tyson J; Lee, Sungsoo S; Stupp, Samuel I

    2012-12-01

    Elucidating the structural information of nanoscale materials in their solvent-exposed state is crucial, as a result, cryogenic transmission electron microscopy (cryo-TEM) has become an increasingly popular technique in the materials science, chemistry, and biology communities. Cryo-TEM provides a method to directly visualize the specimen structure in a solution-state through a thin film of vitrified solvent. This technique complements X-ray, neutron, and light scattering methods that probe the statistical average of all species present; furthermore, cryo-TEM can be used to observe changes in structure over time. In the area of self-assembly, this tool has been particularly powerful for the characterization of natural and synthetic small molecule assemblies, as well as hybrid organic-inorganic composites. In this review, we discuss recent advances in cryogenic TEM in the context of self-assembling systems with emphasis on characterization of transitions observed in response to external stimuli.

  5. Tri-modal microscopy with multiphoton and optical coherence microscopy/tomography for multi-scale and multi-contrast imaging

    PubMed Central

    Chong, Shau Poh; Lai, Tom; Zhou, Yifeng; Tang, Shuo

    2013-01-01

    Multi-scale multimodal microscopy is a very useful technique by providing multiple imaging contrasts with adjustable field of views and spatial resolutions. Here, we present a tri-modal microscope combining multiphoton microscopy (MPM), optical coherence microscopy (OCM) and optical coherence tomography (OCT) for subsurface visualization of biological tissues. The advantages of the tri-modal system are demonstrated on various biological samples. It enables the visualization of multiple intrinsic contrasts including scattering, two-photon excitation fluorescence (TPEF), and second harmonic generation (SHG). It also enables a rapid scanning over a large tissue area and a high resolution zoom-in for cellular-level structures on regions of interest. The tri-modal microscope can be important for label-free imaging to obtain a sufficient set of parameters for reliable sample analysis. PMID:24049679

  6. Differential interference contrast microscopy using light-emitting diode illumination in conjunction with dual optical traps.

    PubMed

    Battle, C; Lautscham, L; Schmidt, C F

    2013-05-01

    Differential interference contrast (DIC) microscopy is a common mode of biological light microscopy used to achieve maximal resolution and contrast with label-free, weakly absorbing specimens such as cells. Maintaining the polarization state of the illuminating light is essential for the technique, and this requirement can conflict with optical trapping. We describe how to optimize DIC imaging using a light-emitting diode illumination source in a microscope while integrating a dual optical trap into the set up. Every time a polarized light beam reflects off or transmits through a dichroic mirror in the beam path, its polarization state will change if it is not polarized exactly parallel (p) or perpendicular (s) to the plane of incidence. We observe wavelength-dependent optical rotation and depolarization effects in our illumination light upon reflection from/transmission through dichroic mirrors in the beam path, resulting in significant degradation of image quality. We describe a method to compensate for these effects by introducing quarter-waveplates and a laser clean-up filter into the imaging pathway. We show that this approach achieves a full recovery of image quality.

  7. Light-sheet photoacoustic microscopy (LIS-PAM) with optical ultrasound detection

    NASA Astrophysics Data System (ADS)

    Nuster, Robert; Slezak, Paul; Paltauf, Guenther

    2016-03-01

    Photoacoustic (or optoacoustic) microscopy has great potential as a diagnostic tool in biomedical research. For in vivo imaging, an important requirement is to keep the measurement time as short as possible. In light-sheet photoacoustic microscopy (LIS-PAM) a cylindrical lens illuminates a thin section perpendicular to the sample surface with a short laser pulse and a projection of the excited acoustic wave pattern leaving the sample is recorded with a camera. From the recorded data, a B-scan photoacoustic image is obtained by applying a two-dimensional reconstruction algorithm, without requiring any mechanical scanning. Hence, LIS-PAM is capable of real-time B-scan imaging with acoustical resolution within the individual B-scans and optical out of plane resolution up to a depth limited by optical diffusion. A 3D image is composed of reconstructed B-scan images recorded while scanning the excitation line along the sample surface. Using a camera with 200 Hz frame rate a C-scan image (5x5 mm2 field of view) can be recorded in less than 5 seconds (without averaging). The achievable sensitivity and resolution of the optical phase contrast detection system were estimated theoretically with 0.34 kPa mm without averaging and 30 μm, respectively. A first experiment on a phantom that mimics tissue properties shows the applicability of this technique for in-vivo imaging.

  8. A quantitative framework for the analysis of multimodal optical microscopy images

    PubMed Central

    Bower, Andrew J.; Chidester, Benjamin; Li, Joanne; Zhao, Youbo; Marjanovic, Marina; Chaney, Eric J.; Do, Minh N.

    2017-01-01

    Background Multimodal optical microscopy, a set of imaging techniques based on unique, yet complementary contrast mechanisms and spatially and temporally co-registered data acquisition, has emerged as a powerful biomedical tool. However, the analysis of the dense, high-dimensional datasets acquired by these instruments remains mostly qualitative and restricted to analysis of each modality individually. Methods Using a custom-built multimodal nonlinear optical microscope, high dimensional datasets were acquired for automated classification of functional cell states as well as identification of histopathological features in tissues slices. Supervised classification of cell death modes was performed through support vector machines (SVM) and semi-supervised classification of tissue slices was performed through the use of the expectation maximization (EM) algorithm. Results Applications of these techniques to the automated classification of cell death modes as well as to the identification of tissue components in fixed ex vivo tissue slices are presented. The analysis techniques developed provide a direct link between multimodal image contrast and biological structure and function, resulting in highly accurate classification in both settings. Conclusions Quantification of multimodal optical microscopy images through statistical modeling of the high dimensional data acquired gives a strong correlation between biological structure and function and image contrast. These methods are sensitive to the identification of diagnostic, cellular-level features important in a variety of clinical settings. PMID:28275557

  9. An Optical Cryostat for Use in Microscopy Cooled by Stirling-Type Pulse Tube Cryocooler

    NASA Astrophysics Data System (ADS)

    Liubiao, Chen; Qiang, Zhou; Xiaoshuang, Zhu; Yuan, Zhou; Junjie, Wang

    The few products of an optical cryostat for use in microscopy in commercialapplications are generally cooled by liquid nitrogen, liquid helium or cryocoolers such as G-M cryocooler or G-M type pulse tube cryocooler (PTC). Sometimes it is not convenient to use G-M cryocooler or G-M type PTC because of its noise and big size; and in some places, liquid nitrogen, especially liquid helium, is not easily available. To overcome this limitation, an optical cryostat for use in microscopy cooled by a Stirling-type pulse tube cryocooler (SPTC) has been designed, built and tested. The refrigerator system SPTC is an important component of the optical cryostat; it has the advantages of compactness, high efficiency, and low vibration. For simplification and compactness, single-stage configuration with coaxial arrangement was employed in the developed SPTC. In order to lower the vibration, the separated configuration was adopted; its compressor and pulse tube are connected with a flexible connecting tube. At present, a lowest temperature of 20 K could be achieved. The temperature fluctuation can be controlled at ±10 mK by adjusting the input electric power to the compressor; and some considerations for further improvement will also be described in this paper.

  10. Stochastic optical reconstruction microscopy-based relative localization analysis (STORM-RLA) for quantitative nanoscale assessment of spatial protein organization.

    PubMed

    Veeraraghavan, Rengasayee; Gourdie, Robert G

    2016-11-07

    The spatial association between proteins is crucial to understanding how they function in biological systems. Colocalization analysis of fluorescence microscopy images is widely used to assess this. However, colocalization analysis performed on two-dimensional images with diffraction-limited resolution merely indicates that the proteins are within 200-300 nm of each other in the xy-plane and within 500-700 nm of each other along the z-axis. Here we demonstrate a novel three-dimensional quantitative analysis applicable to single-molecule positional data: stochastic optical reconstruction microscopy-based relative localization analysis (STORM-RLA). This method offers significant advantages: 1) STORM imaging affords 20-nm resolution in the xy-plane and <50 nm along the z-axis; 2) STORM-RLA provides a quantitative assessment of the frequency and degree of overlap between clusters of colabeled proteins; and 3) STORM-RLA also calculates the precise distances between both overlapping and nonoverlapping clusters in three dimensions. Thus STORM-RLA represents a significant advance in the high-throughput quantitative assessment of the spatial organization of proteins.

  11. Label-free nonlinear optical microscopy detects early markers for osteogenic differentiation of human stem cells

    NASA Astrophysics Data System (ADS)

    Hofemeier, Arne D.; Hachmeister, Henning; Pilger, Christian; Schürmann, Matthias; Greiner, Johannes F. W.; Nolte, Lena; Sudhoff, Holger; Kaltschmidt, Christian; Huser, Thomas; Kaltschmidt, Barbara

    2016-05-01

    Tissue engineering by stem cell differentiation is a novel treatment option for bone regeneration. Most approaches for the detection of osteogenic differentiation are invasive or destructive and not compatible with live cell analysis. Here, non-destructive and label-free approaches of Raman spectroscopy, coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG) microscopy were used to detect and image osteogenic differentiation of human neural crest-derived inferior turbinate stem cells (ITSCs). Combined CARS and SHG microscopy was able to detect markers of osteogenesis within 14 days after osteogenic induction. This process increased during continued differentiation. Furthermore, Raman spectroscopy showed significant increases of the PO43‑ symmetric stretch vibrations at 959 cm‑1 assigned to calcium hydroxyapatite between days 14 and 21. Additionally, CARS microscopy was able to image calcium hydroxyapatite deposits within 14 days following osteogenic induction, which was confirmed by Alizarin Red-Staining and RT- PCR. Taken together, the multimodal label-free analysis methods Raman spectroscopy, CARS and SHG microscopy can monitor osteogenic differentiation of adult human stem cells into osteoblasts with high sensitivity and spatial resolution in three dimensions. Our findings suggest a great potential of these optical detection methods for clinical applications including in vivo observation of bone tissue–implant-interfaces or disease diagnosis.

  12. Characterization of atherosclerotic arterial tissue using multimodal non-linear optical microscopy

    NASA Astrophysics Data System (ADS)

    Cicchi, Riccardo; Matthäus, Christian; Meyer, Tobias; Lattermann, Annika; Dietzek, Benjamin; Brehm, Bernhard R.; Popp, Jürgen; Pavone, Francesco S.

    2013-06-01

    Atherosclerosis is among the most widespread cardiovascular diseases and one of the leading cause of death in the Western World. Characterization of arterial tissue in atherosclerotic condition is extremely interesting from the diagnostic point of view. Routinely used diagnostic methods, such as histopathological examination, are limited to morphological analysis of the examined tissues, whereas an exhaustive characterization requires a morpho-functional approach. Non-linear microscopy techniques have the potential to bridge this gap by providing morpho-functional information in a label-free way. Here we employed multiple non-linear microscopy techniques, including CARS, TPF, and SHG to provide intrinsic optical contrast from various tissue components in both arterial wall and atherosclerotic plaques. CARS and TPF microscopy were used to respectively image lipid depositions within plaques and elastin in the arterial wall. Cholesterol deposition in the lumen and collagen in the arterial wall were selectively imaged by SHG microscopy and distinguished by forward-backward SHG ratio. Image pattern analysis allowed characterizing collagen organization in different tissue regions. The presented method has the potential to find a stable place in clinical setting as well as to be applied in vivo in the near future.

  13. Structured illumination-based super-resolution optical microscopy for hemato- and cyto-pathology applications.

    PubMed

    Zhang, Tieqiao; Osborn, Samantha; Brandow, Chloe; Dwyre, Denis; Green, Ralph; Lane, Stephen; Wachsmann-Hogiu, Sebastian

    2013-01-01

    Structured illumination fluorescence microscopy utilizes interfering light and the moiré effect to enhance spatial resolution to about a half of that of conventional light microscopy, i.e. approximately 90 nm. In addition to the enhancement in the x and y directions, it also allows enhancement of resolution in the z- direction by the same factor of two (to approximately 220 nm), making it a powerful tool for 3-D morphology studies of fluorescently labeled cells or thin tissue sections. In this report, we applied this technique to several types of blood cells that are commonly seen in hematopathology. Compared with standard brightfield and ordinary fluorescence microscopy images, the 3-D morphology results clearly reveal the morphological features of different types of normal blood cells. We have also used this technique to evaluate morphologies of abnormal erythrocytes and compare them with those recorded on normal cells. The results give a very intuitive presentation of morphological structures of erythrocytes with great details. This research illustrates the potential of this technique to be used in hematology and cyto-pathology studies aimed at identifying nanometer-sized features that cannot be distinguished otherwise with conventional optical microscopy.

  14. Lamin B distribution and association with peripheral chromatin revealed by optical sectioning and electron microscopy tomography

    PubMed Central

    1993-01-01

    We have used a combination of immunogold staining, optical sectioning light microscopy, intermediate voltage electron microscopy, and EM tomography to examine the distribution of lamin B over the nuclear envelope of CHO cells. Apparent inconsistencies between previously published light and electron microscopy studies of nuclear lamin staining were resolved. At light microscopy resolution, an apparent open fibrillar network is visualized. Colocalization of lamin B and nuclear pores demonstrates that these apparent fibrils, separated by roughly 0.5 micron, are anti-correlated with the surface distribution of nuclear pores; pore clusters lie between or adjacent to regions of heavy lamin B staining. Examination at higher, EM resolution reveals that this apparent lamin B network does not correspond to an actual network of widely spaced, discrete bundles of lamin filaments. Rather it reflects a quantitative variation in lamin staining over a roughly 0.5-micron size scale, superimposed on a more continuous but still complex distribution of lamin filaments, spatially heterogeneous on a 0.1-0.2-micron size scale. Interestingly, lamin B staining at this higher resolution is highly correlated to the underlying chromatin distribution. Heavy concentrations of lamin B directly "cap" the surface of envelope associated, large-scale chromatin domains. PMID:8276889

  15. Label-free nonlinear optical microscopy detects early markers for osteogenic differentiation of human stem cells

    PubMed Central

    Hofemeier, Arne D.; Hachmeister, Henning; Pilger, Christian; Schürmann, Matthias; Greiner, Johannes F. W.; Nolte, Lena; Sudhoff, Holger; Kaltschmidt, Christian; Huser, Thomas; Kaltschmidt, Barbara

    2016-01-01

    Tissue engineering by stem cell differentiation is a novel treatment option for bone regeneration. Most approaches for the detection of osteogenic differentiation are invasive or destructive and not compatible with live cell analysis. Here, non-destructive and label-free approaches of Raman spectroscopy, coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG) microscopy were used to detect and image osteogenic differentiation of human neural crest-derived inferior turbinate stem cells (ITSCs). Combined CARS and SHG microscopy was able to detect markers of osteogenesis within 14 days after osteogenic induction. This process increased during continued differentiation. Furthermore, Raman spectroscopy showed significant increases of the PO43− symmetric stretch vibrations at 959 cm−1 assigned to calcium hydroxyapatite between days 14 and 21. Additionally, CARS microscopy was able to image calcium hydroxyapatite deposits within 14 days following osteogenic induction, which was confirmed by Alizarin Red-Staining and RT- PCR. Taken together, the multimodal label-free analysis methods Raman spectroscopy, CARS and SHG microscopy can monitor osteogenic differentiation of adult human stem cells into osteoblasts with high sensitivity and spatial resolution in three dimensions. Our findings suggest a great potential of these optical detection methods for clinical applications including in vivo observation of bone tissue–implant-interfaces or disease diagnosis. PMID:27225821

  16. Fault localization and analysis in semiconductor devices with optical-feedback infrared confocal microscopy

    SciTech Connect

    Sarmiento, Raymund; Cemine, Vernon Julius; Tagaca, Imee Rose; Salvador, Arnel; Mar Blanca, Carlo; Saloma, Caesar

    2007-11-01

    We report on a cost-effective optical setup for characterizing light-emitting semiconductor devices with optical-feedback confocal infrared microscopy and optical beam-induced resistance change.We utilize the focused beam from an infrared laser diode to induce local thermal resistance changes across the surface of a biased integrated circuit (IC) sample. Variations in the multiple current paths are mapped by scanning the IC across the focused beam. The high-contrast current maps allow accurate differentiation of the functional and defective sites, or the isolation of the surface-emittingp-i-n devices in the IC. Optical beam-induced current (OBIC) is not generated since the incident beam energy is lower than the bandgap energy of the p-i-n device. Inhomogeneous current distributions in the IC become apparent without the strong OBIC background. They are located at a diffraction-limited resolution by referencing the current maps against the confocal reflectance image that is simultaneously acquired via optical-feedback detection. Our technique permits the accurate identification of metal and semiconductor sites as well as the classification of different metallic structures according to thickness, composition, or spatial inhomogeneity.

  17. Advancement of Solidification Processing Technology Through Real Time X-Ray Transmission Microscopy: Sample Preparation

    NASA Technical Reports Server (NTRS)

    Stefanescu, D. M.; Curreri, P. A.

    1996-01-01

    Two types of samples were prepared for the real time X-ray transmission microscopy (XTM) characterization. In the first series directional solidification experiments were carried out to evaluate the critical velocity of engulfment of zirconia particles in the Al and Al-Ni eutectic matrix under ground (l-g) conditions. The particle distribution in the samples was recorded on video before and after the samples were directionally solidified. In the second series samples of the above two type of composites were prepared for directional solidification runs to be carried out on the Advanced Gradient Heating Facility (AGHF) aboard the space shuttle during the LMS mission in June 1996. X-ray microscopy proved to be an invaluable tool for characterizing the particle distribution in the metal matrix samples. This kind of analysis helped in determining accurately the critical velocity of engulfment of ceramic particles by the melt interface in the opaque metal matrix composites. The quality of the cast samples with respect to porosity and instrumented thermocouple sheath breakage or shift could be easily viewed and thus helped in selecting samples for the space shuttle experiments. Summarizing the merits of this technique it can be stated that this technique enabled the use of cast metal matrix composite samples since the particle location was known prior to the experiment.

  18. Evaluation of fractional photothermolysis effect in a mouse model using nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Guo, Han Wen; Tseng, Te-Yu; Dong, Chen-Yuan; Tsai, Tsung-Hua

    2014-07-01

    Fractional photothermolysis (FP) induces discrete columns of photothermal damage in skin dermis, thereby promoting collagen regeneration. This technique has been widely used for treating wrinkles, sun damage, and scar. In this study, we evaluate the potential of multiphoton microscopy as a noninvasive imaging modality for the monitoring of skin rejuvenation following FP treatment. The dorsal skin of a nude mouse underwent FP treatment in order to induce microthermal zones (MTZs). We evaluated the effect of FP on skin remodeling at 7 and 14 days after treatment. Corresponding histology was performed for comparison. After 14 days of FP treatment at 10 mJ, the second harmonic generation signal recovered faster than the skin treated with 30 mJ, indicating a more rapid regeneration of dermal collagen at 10 mJ. Our results indicate that nonlinear optical microscopy is effective in detecting the damaged areas of MTZ and monitoring collagen regeneration following FP treatment.

  19. Dynamic structured illumination microscopy: Focused imaging and optical sectioning for moving objects

    NASA Astrophysics Data System (ADS)

    Krzewina, Leo G.; Kim, Myung K.

    2006-02-01

    Structured illumination microscopy (SIM) is a valuable tool for three-dimensional microscopy and has numerous applications in bioscience. Its success has been limited to static objects, though, as three sequential image acquisitions are required per final processed, focused image. To overcome this problem we have developed a multicolored grid which when used in tandem with a color camera is capable of performing SIM with just a single exposure. Images and movies demonstrating optical sectioning of three-dimensional objects are presented, and results of applying color SIM for wide-field focused imaging are compared to those of SIM. From computer modeling and analytical calculations a theoretical estimate of the maximum observable object velocity in both the lateral and axial directions is available, implying that the new method will be capable of imaging a variety of live objects. Sample images of the technique applied to lens paper and a pigeon feather are included to show both advantages and disadvantages of CSIM.

  20. Stochastic Optical Reconstruction Microscopy Imaging of Microtubule Arrays in Intact Arabidopsis thaliana Seedling Roots

    PubMed Central

    Dong, Bin; Yang, Xiaochen; Zhu, Shaobin; Bassham, Diane C.; Fang, Ning

    2015-01-01

    Super-resolution fluorescence microscopy has generated tremendous success in revealing detailed subcellular structures in animal cells. However, its application to plant cell biology remains extremely limited due to numerous technical challenges, including the generally high fluorescence background of plant cells and the presence of the cell wall. In the current study, stochastic optical reconstruction microscopy (STORM) imaging of intact Arabidopsis thaliana seedling roots with a spatial resolution of 20–40 nm was demonstrated. Using the super-resolution images, the spatial organization of cortical microtubules in different parts of a whole Arabidopsis root tip was analyzed quantitatively, and the results show the dramatic differences in the density and spatial organization of cortical microtubules in cells of different differentiation stages or types. The method developed can be applied to plant cell biological processes, including imaging of additional elements of the cytoskeleton, organelle substructure, and membrane domains. PMID:26503365

  1. Uptake of gold nanoparticles in healthy and tumor cells visualized by nonlinear optical microscopy.

    PubMed

    Rago, Gianluca; Bauer, Brigitte; Svedberg, Fredrik; Gunnarsson, Linda; Ericson, Marica B; Bonn, Mischa; Enejder, Annika

    2011-05-05

    Understanding the mechanism underlying the interactions between inorganic nanostructures and biological systems is crucial for several rapidly growing fields that rely on nano-bio interactions. In particular, the further development of cell-targeted drug delivery using metallic nanoparticles (NP) requires new tools for understanding the mechanisms triggered by the contact of NPs with membranes in different cells at the subcellular level. Here we present a novel concept of multimodal microscopy, enabling three-dimensional imaging of the distribution of gold NPs in living, unlabeled cells. Our approach combines multiphoton induced luminescence (MIL) with coherent anti-Stokes Raman scattering (CARS) microscopy. Comparison with transmission electron microscopy (TEM) reveals in vivo sensitivity down to the single nanostructure. By monitoring the incorporation of NPs in human healthy epidermal keratinocytes and squamous carcinoma cells (SCC), we address the feasibility of noninvasive delivery of NPs for therapeutic purposes. While neutralizing PEG coating was confirmed to prevent NP integration in SCCs, an unexpectedly efficient integration of NPs into keratinocytes was observed. These results, independently validated using TEM, demonstrate the need for advanced surface modification protocols to obtain tumor selectivity for NP delivery. The CARS/MIL microscopy platform presented here is thus a promising tool for noninvasive study of the interaction between NPs and cell.

  2. Recent Advances in Photonic Devices for Optical Computing and the Role of Nonlinear Optics-Part II

    NASA Technical Reports Server (NTRS)

    Abdeldayem, Hossin; Frazier, Donald O.; Witherow, William K.; Banks, Curtis E.; Paley, Mark S.

    2007-01-01

    The twentieth century has been the era of semiconductor materials and electronic technology while this millennium is expected to be the age of photonic materials and all-optical technology. Optical technology has led to countless optical devices that have become indispensable in our daily lives in storage area networks, parallel processing, optical switches, all-optical data networks, holographic storage devices, and biometric devices at airports. This chapters intends to bring some awareness to the state-of-the-art of optical technologies, which have potential for optical computing and demonstrate the role of nonlinear optics in many of these components. Our intent, in this Chapter, is to present an overview of the current status of optical computing, and a brief evaluation of the recent advances and performance of the following key components necessary to build an optical computing system: all-optical logic gates, adders, optical processors, optical storage, holographic storage, optical interconnects, spatial light modulators and optical materials.

  3. Combining digital holographic microscopy and optical tweezers: a new route in microfluidic

    NASA Astrophysics Data System (ADS)

    Miccio, L.; Memmolo, P.; Merola, F.; Paturzo, M.; Finizio, A.; Grilli, S.; Ferraro, P.

    2012-04-01

    An optical configuration is realized to obtain quantitative phase-contrast maps able to characterize particles floating in a microfluidic chamber by interference microscopy. The novelty is the possibility to drive the sample and measure it thorough the same light path. That is realized by an optical setup made of two light beams coming from the same laser source. One beam provides the optical forces for driving the particle along the desired path and, at same time, it works as object beam in the digital holographic microscope (DHM). The second one acts as reference beam, allowing recording of an interference fringe pattern (i.e., the digital hologram) in an out-of-focus image plane. This work finds application in the field of micromanipulation as, the devise developed allows to operate in microfluidic chambers driving samples flowing in very small volumes. Recently, the field of optical particle micro-manipulation has had rapid growth, due to Optical Tweezers development. A particle is trapped or moved along certain trajectories according to the intensity and phase distribution of the laser beam used. Here, particles freely floating are driven by optical forces along preferential directions and then analyzed by a DHM to numerically calculate their phase-contrast signature. The improvement is that one laser source is employed for making two jobs: driving and analyze the sample. We use two slightly off-axis laser beams coming from a single laser source. The interference between them gives the possibility to record in real-time a sequence of digital holograms, while one of the beam creates the driving force. By this method, a great amount of particles can be analyzed by a real-time recording of DH movies. This allows one to examine each particle at time and characterize it. The optical configuration and the working method are illustrated. Experimental results are shown for polymeric particles and in-vitro.

  4. Optical clearing assisted confocal microscopy of ex vivo transgenic mouse skin

    NASA Astrophysics Data System (ADS)

    Song, Eunjoo; Ahn, YoonJoon; Ahn, Jinhyo; Ahn, Soyeon; Kim, Changhwan; Choi, Sanghoon; Boutilier, Richard Martin; Lee, Yongjoong; Kim, Pilhan; Lee, Ho

    2015-10-01

    We examined the optical clearing assisted confocal microscopy of the transgenic mouse skin. The pinna and dorsal skin were imaged with a confocal microscope after the application of glycerol and FocusClear. In case of the glycerol-treated pinna, the clearing was minimal due to the inefficient permeability. However, the imaging depth was improved when the pinna was treated with FocusClear. In case of dorsal skin, we were able to image deeply to the subcutaneous connective tissue with both agents. Various skin structures such as the vessel, epithelium cells, cartilage, dermal cells, and hair follicles were clearly imaged.

  5. Occlusal overload investigations by noninvasive technology: fluorescence microscopy and en-face optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Marcauteanu, Corina; Negrutiu, Meda; Sinescu, Cosmin; Demjan, Enikö; Hughes, Michael; Bradu, Adrian; Dobre, George; Podoleanu, Adrian G.

    2009-07-01

    The aim of this study is the early detection and monitoring of occlusal overload in bruxing patients. En-Face Optical coherence tomography (eF-OCT) and fluorescence microscopy (FM) were used for the imaging of several anterior teeth extracted from patients with light active bruxism. We found a characteristic pattern of enamel cracks, that reached the tooth surface. We concluded that the combination of the en-Face OCT and FM is a promising non-invasive alternative technique for reliable monitoring of occlusal overload.

  6. Selective observation of starch in a water plant using optical sum-frequency microscopy

    NASA Astrophysics Data System (ADS)

    Miyauchi, Yoshihiro; Sano, Haruyuki; Mirzutani, Goro

    2006-07-01

    The photosynthesis, transfer, and storage of starch are the most important biogenic processes occurring in plants. In order to observe the colorless and transparent starch granules in a plant, a chemical pretreatment such as staining of the starch is currently required, which seriously damages the tissue cells in the plant. We demonstrate that nondestructive chemical analysis of starch granules in a plant can be performed by using optical second-harmonic and sum-frequency microscopy. These techniques for in vivo analysis will provide extremely useful information about saccharides in a plant and can be extended to the analysis of many other materials, from living tissue to semiconductors.

  7. Study of environmental biodegradation of LDPE films in soil using optical and scanning electron microscopy.

    PubMed

    Mumtaz, Tabassum; Khan, M R; Hassan, Mohd Ali

    2010-07-01

    An outdoor soil burial test was carried out to evaluate the degradation of commercially available LDPE carrier bags in natural soil for up to 2 years. Biodegradability of low density polyethylene films in soil was monitored using both optical and scanning electron microscopy (SEM). After 7-9 months of soil exposure, microbial colonization was evident on the film surface. Exposed LDPE samples exhibit progressive changes towards degradation after 17-22 months. SEM images reveal signs of degradation such as exfoliation and formation of cracks on film leading to disintegration. The possible degradation mode and consequences on the use and disposal of LDPE films is discussed.

  8. In vivo noninvasive monitoring of microhemodynamics using optical-resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Hu, Song; Maslov, Konstantin I.; Wang, Lihong V.

    2009-02-01

    Microvascular autoregulation is an intrinsic ability of vascular beds to compensate for the fluctuation in blood flow and tissue oxygen delivery. This function is crucial to maintaining the local metabolic activity. Here, using optical-resolution photoacoustic microscopy (OR-PAM), we clearly observed vasomotion and vasodilation in the intact mouse microcirculation in vivo in response to the changes in physiological state. Our results show that a significant lowfrequency vasomotion can be seen under hyperoxia but not hypoxia. Moreover, significant vasodilation is observed when the animal status is switched from hyperoxia to hypoxia. Our data show that arterioles have more pronounced vasodilation than venules.

  9. Microtomography and improved resolution in cathodoluminescence microscopy using confocal mirror optics

    SciTech Connect

    Chan, D.S.H.; Liu, Y.Y.; Phang, J.C.H.; Rau, E.; Sennov, R.; Gostev, A.V.

    2004-10-01

    Cathodoluminescence in scanning electron microscopy observed using an ellipsoidal confocal light collector system can offer improved resolution and an implementation of microtomography. With this signal collection system, the resolution limit is no longer determined by the beam and specimen properties but by the system optics. This possibility is demonstrated by the modeling of light transport in cathodoluminescent materials and in the ellipsoidal confocal system which collects the light emission. The conditions for the high-resolution three-dimensional visualization of microstructure within the generation volume of cathodoluminescence emission is described.

  10. Nanoscale optical properties of metal nanoparticles probed by Second Harmonic Generation microscopy.

    PubMed

    Shen, Hong; Nguyen, Ngoc; Gachet, David; Maillard, Vincent; Toury, Timothée; Brasselet, Sophie

    2013-05-20

    We report spatial and vectorial imaging of local fields' confinement properties in metal nanoparticles with branched shapes, using Second Harmonic Generation (SHG) microscopy. Taking advantage of the coherent nature of this nonlinear process, the technique provides a direct evidence of the coupling between the excitation polarization and both localization and polarization specificities of local fields at the sub-diffraction scale. These combined features, which are governed by the nanoparticles' symmetry, are not accessible using other contrasts such as linear optical techniques or two-photon luminescence.

  11. Optical parametric oscillator-based light source for coherent Raman scattering microscopy: practical overview

    NASA Astrophysics Data System (ADS)

    Brustlein, Sophie; Ferrand, Patrick; Walther, Nico; Brasselet, Sophie; Billaudeau, Cyrille; Marguet, Didier; Rigneault, Hervé

    2011-02-01

    We present the assets and constraints of using optical parametric oscillators (OPOs) to perform point scanning nonlinear microscopy and spectroscopy with special emphasis on coherent Raman spectroscopy. The difterent possible configurations starting with one OPO and two OPOs are described in detail and with comments that are intended to be practically useful for the user. Explicit examples on test samples such as nonlinear organic crystal, polystyrene beads, and fresh mouse tissues are given. Special emphasis is given to background-free coherent Raman anti-Stokes scattering (CARS) imaging, including CARS hyperspectral imaging in a fully automated mode with commercial OPOs.

  12. Dynamic multimodal full-field optical coherence tomography and fluorescence structured illumination microscopy

    NASA Astrophysics Data System (ADS)

    Thouvenin, Olivier; Fink, Mathias; Boccara, Claude

    2017-02-01

    We report on the development of a configuration of a multimodal full-field optical coherence tomography (FF-OCT) and fluorescence microscope. Our system can simultaneously acquire FF-OCT and structured illumination microscopy images. Dynamic parallel evolution of tissue microstructures and biochemical environments can be visualized. We use high numerical aperture objectives to optimize the combination of the two modalities. We imaged the propagation of mechanical waves initiated by calcium waves in a heart wall to illustrate the interest of simultaneous recording of mechanical and biochemical information.

  13. Phase stabilized homodyne of infrared scattering type scanning near-field optical microscopy

    SciTech Connect

    Xu, Xiaoji G.; Gilburd, Leonid; Walker, Gilbert C.

    2014-12-29

    Scattering type scanning near-field optical microscopy (s-SNOM) allows sub diffraction limited spatial resolution. Interferometric homodyne detection in s-SNOM can amplify the signal and extract vibrational responses based on sample absorption. A stable reference phase is required for a high quality homodyne-detected near-field signal. This work presents the development of a phase stabilization mechanism for s-SNOM to provide stable homodyne conditions. The phase stability is found to be better than 0.05 rad for the mid infrared light source. Phase stabilization results in improved near field images and vibrational spectroscopies. Spatial inhomogeneities of the boron nitride nanotubes are measured and compared.

  14. Optical scanning holography as a technique for high-resolution three-dimensional biological microscopy

    NASA Astrophysics Data System (ADS)

    Swoger, Jim; Martinez-Corral, Manuel; Huisken, Jan; Stelzer, Ernst H. K.

    2002-09-01

    The applicability of optical scanning holography (OSH) to the field of microscopic imaging for biological applications is assessed. A generalized mathematical description of OSH that takes into account polarization effects, high numerical apertures, and generalized illumination wave fronts is presented. This description is used to show that the proposed single-beam scanning technique relaxes the restrictions under which OSH functions correctly compared with the conventional double-beam scanning method. It is also shown that, although in general OSH is restricted to thin samples, this condition can be relaxed in nonrefracting fluorescence samples, which are of importance in biological microscopy.

  15. Approximate Bayesian computation for estimating number concentrations of monodisperse nanoparticles in suspension by optical microscopy

    NASA Astrophysics Data System (ADS)

    Röding, Magnus; Zagato, Elisa; Remaut, Katrien; Braeckmans, Kevin

    2016-06-01

    We present an approximate Bayesian computation scheme for estimating number concentrations of monodisperse diffusing nanoparticles in suspension by optical particle tracking microscopy. The method is based on the probability distribution of the time spent by a particle inside a detection region. We validate the method on suspensions of well-controlled reference particles. We illustrate its usefulness with an application in gene therapy, applying the method to estimate number concentrations of plasmid DNA molecules and the average number of DNA molecules complexed with liposomal drug delivery particles.

  16. Nanometric resolution using far-field optical tomographic microscopy in the multiple scattering regime

    SciTech Connect

    Girard, Jules; Maire, Guillaume; Giovannini, Hugues; Belkebir, Kamal; Chaumet, Patrick C.; Sentenac, Anne; Talneau, Anne

    2010-12-15

    The resolution of optical far-field microscopes is classically diffraction-limited to half the illumination wavelength. We show experimentally that this fundamental limit does not apply in the multiple scattering regime. We used tomographic diffractive microscopy at 633 nm to image two pairs of closely spaced rods (with a width and interdistance of 50 nm) of widely different diffractive properties. Using an inversion algorithm accounting for multiple scattering, only the pair of highly diffracting rods could be clearly visualized with a resolution similar to that of an atomic force microscope.

  17. Fast optical sectioning obtained by structured illumination microscopy using a digital mirror device.

    PubMed

    Xu, Dongli; Jiang, Tao; Li, Anan; Hu, Bihe; Feng, Zhao; Gong, Hui; Zeng, Shaoqun; Luo, Qingming

    2013-06-01

    High-throughput optical imaging is critical to obtain large-scale neural connectivity information of brain in neuroscience. Using a digital mirror device and a scientific complementary metal-oxide semiconductor camera, we report a significant speed improvement of structured illumination microscopy (SIM), which produces a maximum SIM net frame rate of 133 Hz. We perform three-dimensional (3-D) imaging of mouse brain slices at diffraction-limited resolution and demonstrate the fast 3-D imaging capability to a large sample with an imaging rate of 6.9×10(7)  pixel/s of our system, an order of magnitude faster than previously reported.

  18. Fast optical sectioning obtained by structured illumination microscopy using a digital mirror device

    NASA Astrophysics Data System (ADS)

    Xu, Dongli; Jiang, Tao; Li, Anan; Hu, Bihe; Feng, Zhao; Gong, Hui; Zeng, Shaoqun; Luo, Qingming

    2013-06-01

    High-throughput optical imaging is critical to obtain large-scale neural connectivity information of brain in neuroscience. Using a digital mirror device and a scientific complementary metal-oxide semiconductor camera, we report a significant speed improvement of structured illumination microscopy (SIM), which produces a maximum SIM net frame rate of 133 Hz. We perform three-dimensional (3-D) imaging of mouse brain slices at diffraction-limited resolution and demonstrate the fast 3-D imaging capability to a large sample with an imaging rate of 6.9 pixel/s of our system, an order of magnitude faster than previously reported.

  19. Optical-resolution photoacoustic microscopy of angiogenesis in a transgenic mouse model

    NASA Astrophysics Data System (ADS)

    Hu, Song; Oladipupo, Sunday; Yao, Junjie; Santeford, Andrea C.; Maslov, Konstantin; Kovalski, Joanna; Arbeit, Jeffrey M.; Wang, Lihong V.

    2010-02-01

    A major obstacle in studying angiogenesis is the inability to noninvasively image neovascular development in an individual animal. We applied optical-resolution photoacoustic microscopy (OR-PAM) to determine the kinetics of hypoxia-inducible factor-1 (HIF-1)-mediated angiogenesis in a transgenic mouse model. During continuous 30-day activation of HIF-1α, we used OR-PAM to monitor alterations in microvasculature in transgenic mice compared to nontransgenic mice. OR-PAM has demonstrated the potential to precisely monitor antiangiogenic therapy of human cancers, allowing for rapid determinations of therapeutic efficacy or resistance.

  20. Spectral-domain optical coherence phase microscopy for label-free multiplexed protein microarray assay.

    PubMed

    Joo, Chulmin; Ozkumur, Emre; Unlü, M Selim; Boer, Johannes F de

    2009-10-15

    Quantitative measurement of affinities and kinetics of various biomolecular interactions such as protein-protein, protein-DNA and receptor-ligand is central to our understanding of basic molecular and cellular functions and is useful for therapeutic evaluation. Here, we describe a laser-scanning quantitative imaging method, referred to as spectral-domain optical coherence phase microscopy, as an optical platform for label-free detection of biomolecular interactions. The instrument is based on a confocal interferometric microscope that enables depth-resolved quantitative phase measurements on sensor surface with high spatial resolution and phase stability. We demonstrate picogram per square millimeter surface mass sensitivity, and show its sensing capability by presenting static and dynamic detection of multiplexed protein microarray as immobilized antigens capture their corresponding antibodies.

  1. In-vivo monitoring rat skin wound healing using nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Chen, Jing; Guo, Chungen; Zhang, Fan; Xu, Yahao; Zhu, Xiaoqin; Xiong, Shuyuan; Chen, Jianxin

    2014-11-01

    Nonlinear optical microscopy (NLOM) was employed for imaging and evaluating the wound healing process on rat skin in vivo. From the high-resolution nonlinear optical images, the morphology and distribution of specific biological markers in cutaneous wound healing such as fibrin clot, collagens, blood capillaries, and hairs were clearly observed at 1, 5 and 14 days post injury. We found that the disordered collagen in the fibrin clot at day 1 was replaced by regenerative collagen at day 5. By day 14, the thick collagen with well-network appeared at the original margin of the wound. These findings suggested that NLOM is ideal for noninvasively monitoring the progress of wound healing in vivo.

  2. High speed optical coherence microscopy with autofocus adjustment and a miniaturized endoscopic imaging probe

    PubMed Central

    Aguirre, Aaron D.; Sawinski, Juergen; Huang, Shu-Wei; Zhou, Chao; Denk, Winfried; Fujimoto, James G.

    2010-01-01

    Optical coherence microscopy (OCM) is a promising technique for high resolution cellular imaging in human tissues. An OCM system for high-speed en face cellular resolution imaging was developed at 1060 nm wavelength at frame rates up to 5 Hz with resolutions of < 4 µm axial and < 2 µm transverse. The system utilized a novel polarization compensation method to combat wavelength dependent source polarization and achieve broadband electro-optic phase modulation compatible with ultrahigh axial resolution. In addition, the system incorporated an auto-focusing feature that enables precise, near real-time alignment of the confocal and coherence gates in tissue, allowing user-friendly optimization of image quality during the imaging procedure. Ex vivo cellular images of human esophagus, colon, and cervix as well as in vivo results from human skin are presented. Finally, the system design is demonstrated with a miniaturized piezoelectric fiber-scanning probe which can be adapted for laparoscopic and endoscopic imaging applications. PMID:20389435

  3. Femtosecond infrared intrastromal ablation and backscattering-mode adaptive-optics multiphoton microscopy in chicken corneas

    PubMed Central

    Gualda, Emilio J.; Vázquez de Aldana, Javier R.; Martínez-García, M. Carmen; Moreno, Pablo; Hernández-Toro, Juan; Roso, Luis; Artal, Pablo; Bueno, Juan M.

    2011-01-01

    The performance of femtosecond (fs) laser intrastromal ablation was evaluated with backscattering-mode adaptive-optics multiphoton microscopy in ex vivo chicken corneas. The pulse energy of the fs source used for ablation was set to generate two different ablation patterns within the corneal stroma at a certain depth. Intrastromal patterns were imaged with a custom adaptive-optics multiphoton microscope to determine the accuracy of the procedure and verify the outcomes. This study demonstrates the potential of using fs pulses as surgical and monitoring techniques to systematically investigate intratissue ablation. Further refinement of the experimental system by combining both functions into a single fs laser system would be the basis to establish new techniques capable of monitoring corneal surgery without labeling in real-time. Since the backscattering configuration has also been optimized, future in vivo implementations would also be of interest in clinical environments involving corneal ablation procedures. PMID:22076258

  4. Ultrahigh-resolution full-field optical coherence microscopy using InGaAs camera

    NASA Astrophysics Data System (ADS)

    Oh, W. Y.; Bouma, B. E.; Iftimia, N.; Yun, S. H.; Yelin, R.; Tearney, G. J.

    2006-01-01

    Full-field optical coherence microscopy (FFOCM) is an interferometric technique for obtaining wide-field microscopic images deep within scattering biological samples. FFOCM has primarily been implemented in the 0.8 μm wavelength range with silicon-based cameras, which may limit penetration when imaging human tissue. In this paper, we demonstrate FFOCM at the wavelength range of 0.9 - 1.4 μm, where optical penetration into tissue is presumably greater owing to decreased scattering. Our FFOCM system, comprising a broadband spatially incoherent light source, a Linnik interferometer, and an InGaAs area scan camera, provided a detection sensitivity of 86 dB for a 2 sec imaging time and an axial resolution of 1.9 μm in water. Images of phantoms, tissue samples, and Xenopus Laevis embryos were obtained using InGaAs and silicon camera FFOCM systems, demonstrating enhanced imaging penetration at longer wavelengths.

  5. Near-field optical microscopy and spectroscopy of few-layer black phosphorous

    NASA Astrophysics Data System (ADS)

    Frenzel, A. J.; Tran, S.; Hinton, J. P.; Sternbach, A. J.; Yang, J.; Gillgren, N.; Lau, C. N.; Basov, D. N.

    Few-layer black phosphorous is a recent addition to the family of two-dimensional (2D) materials which exhibits strongly anisotropic transport and optical properties due to its puckered honeycomb structure. It was recently predicted that this intrinsic anisotropy should manifest in the plasmon dispersion. Additionally, tuning layer number and carrier density can control the dispersion of these collective modes. Scanning near-field optical microscopy (SNOM) has been demonstrated as a powerful method to probe electronic properties, including propagating collective modes, in layered 2D materials. We used SNOM to investigate anisotropic carrier response in few-layer black phosphorous encapsulated by hexagonal boron nitride. In addition to exploring gate-voltage tunability of the electronic response, we demonstrate effective modulation of the near-field signal by ultrafast photoexcitation.

  6. En face speckle reduction in optical coherence microscopy by frequency compounding

    PubMed Central

    Magnain, Caroline; Wang, Hui; Sakadžić, Sava; Fischl, Bruce; Boas, David A.

    2017-01-01

    We report the use of frequency compounding to significantly reduce speckle noise in optical coherence microscopy, more specifically on the en face images. This method relies on the fact that the speckle patterns recorded from different wavelengths simultaneously are independent; hence their summation yields significant reduction in noise, with only a single acquisition. The results of our experiments with microbeads show that the narrow confocal parameter, due to a high numerical aperture objective, restricts the axial resolution loss that would otherwise theoretically broaden linearly with the number of optical frequency bands used. This speckle reduction scheme preserves the lateral resolution since it is performed on individual A-scans. Finally, we apply this technique to images of fixed human brain tissue, showing significant improvements in contrast-to-noise ratio with only moderate loss of axial resolution, in an effort to improve automatic three-dimensional detection of cells and fibers in the cortex. PMID:27128040

  7. Femtosecond infrared intrastromal ablation and backscattering-mode adaptive-optics multiphoton microscopy in chicken corneas.

    PubMed

    Gualda, Emilio J; Vázquez de Aldana, Javier R; Martínez-García, M Carmen; Moreno, Pablo; Hernández-Toro, Juan; Roso, Luis; Artal, Pablo; Bueno, Juan M

    2011-11-01

    The performance of femtosecond (fs) laser intrastromal ablation was evaluated with backscattering-mode adaptive-optics multiphoton microscopy in ex vivo chicken corneas. The pulse energy of the fs source used for ablation was set to generate two different ablation patterns within the corneal stroma at a certain depth. Intrastromal patterns were imaged with a custom adaptive-optics multiphoton microscope to determine the accuracy of the procedure and verify the outcomes. This study demonstrates the potential of using fs pulses as surgical and monitoring techniques to systematically investigate intratissue ablation. Further refinement of the experimental system by combining both functions into a single fs laser system would be the basis to establish new techniques capable of monitoring corneal surgery without labeling in real-time. Since the backscattering configuration has also been optimized, future in vivo implementations would also be of interest in clinical environments involving corneal ablation procedures.

  8. 3D image reconstruction using optical sectioning in confocal scanning microscopy

    NASA Astrophysics Data System (ADS)

    Seo, Jungwoo; Kang, Dong Kyun; Park, Sunglim; Gweon, Dae gab

    2001-10-01

    Confocal scanning microscopy (CSM) has been used in biological application, materials science, semiconductor quality measurement and other non-destructive microscopic application. Small spot of light illuminates a sample, and a small detector that is ideally a point detector collects the reflected or transmitted light having the information of specimen. An image distribution can be reconstructed by a correlation analysis of spots with the high bandwidth. The mechanism for two-dimensional beam scanning and optical sectioning has an important role in CSM as the three-dimensional profiler. The parasitic motion of focus on the detector gives rise to the fatal distortion of an image profile named the extinction effect while using acousto-optical (AO) deflector. The intensity profile for the open loop scanning should be matched with its response for the standard. The non-linearity can be minimized with the optical sectioning or the optical probe of the closed loop control. This paper shows the mathematical expression of the light such as the extinction curve in the optical fields of system using AO deflector, the axial/lateral response experimentally when the error sources change, and the methods of optical sectioning. We propose the progressive methods for the high quality image as the following. At first, for having the corrected image, small spot and long scan range, this paper shows that the optimal design having the multi-objects can be used by choosing the unitary lens device in CSM. At second, in order to compensate for the intensity cancellation at the end profile that may be the cause of waviness for the optical image, this paper shows that it is efficient to schedule the frequency of scan. According to characteristics of the extinction curve and axial/lateral response having the error property, we can define the frequency and sensitivity of as their robustness. Finally, the axial response gives an important motive for the optical section, and the limit of

  9. Simulation of image formation in x-ray coded aperture microscopy with polycapillary optics.

    PubMed

    Korecki, P; Roszczynialski, T P; Sowa, K M

    2015-04-06

    In x-ray coded aperture microscopy with polycapillary optics (XCAMPO), the microstructure of focusing polycapillary optics is used as a coded aperture and enables depth-resolved x-ray imaging at a resolution better than the focal spot dimensions. Improvements in the resolution and development of 3D encoding procedures require a simulation model that can predict the outcome of XCAMPO experiments. In this work we introduce a model of image formation in XCAMPO which enables calculation of XCAMPO datasets for arbitrary positions of the object relative to the focal plane as well as to incorporate optics imperfections. In the model, the exit surface of the optics is treated as a micro-structured x-ray source that illuminates a periodic object. This makes it possible to express the intensity of XCAMPO images as a convolution series and to perform simulations by means of fast Fourier transforms. For non-periodic objects, the model can be applied by enforcing artificial periodicity and setting the spatial period larger then the field-of-view. Simulations are verified by comparison with experimental data.

  10. On-chip integrated lensless microscopy module for optical monitoring of adherent growing mammalian cells.

    PubMed

    Li, Wei; Knoll, Thorsten; Thielecke, Hagen

    2010-01-01

    Lab-on-a-chip systems are increasingly applied in cell-based assays for toxicology and drug testing. In this paper, an on-chip integrated lensless microscopy module using a direct projection method for optical monitoring of the shadow images of adherent growing mammalian cells is presented. The biological cells are conserved and interfaced by a microfabricated cavity chip with a 1 microm thick silicon nitride (Si(3)N(4)) substrate onto the surface of a 5 megapixel CMOS image sensor with 2.2 microm pixel size. The optical resolution of the assembly is estimated by the contact/proximate printing theory from optical lithography. Further characterization is made by imaging microbeads in chips with the Si(3)N(4)-membrane as well as in cavity chips with membranes made from dry film resist (DFR, thickness 20, 40 and 60 microm). The module represents a 3 × optical microscope for cell morphology imaging. The function is demonstrated by the growth monitoring of L929 cells cultured in cavity chips with Si(3)N(4) substrate for 2 days and by checking the colorimetric staining of cells with a compromised membrane.

  11. An integrated optical coherence microscopy imaging and optical stimulation system for optogenetic pacing in Drosophila melanogaster (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Alex, Aneesh; Li, Airong; Men, Jing; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

    2016-03-01

    Electrical stimulation is the clinical standard for cardiac pacing. Although highly effective in controlling cardiac rhythm, the invasive nature, non-specificity to cardiac tissues and possible tissue damage limits its applications. Optogenetic pacing of the heart is a promising alternative, which is non-invasive and more specific, has high spatial and temporal precision, and avoids the shortcomings in electrical stimulation. Drosophila melanogaster, which is a powerful model organism with orthologs of nearly 75% of human disease genes, has not been studied for optogenetic pacing in the heart. Here, we developed a non-invasive integrated optical pacing and optical coherence microscopy (OCM) imaging system to control the heart rhythm of Drosophila at different developmental stages using light. The OCM system is capable of providing high imaging speed (130 frames/s) and ultrahigh imaging resolutions (1.5 μm and 3.9 μm for axial and transverse resolutions, respectively). A light-sensitive pacemaker was developed in Drosophila by specifically expressing the light-gated cation channel, channelrhodopsin-2 (ChR2) in transgenic Drosophila heart. We achieved non-invasive and specific optical control of the Drosophila heart rhythm throughout the fly's life cycle (larva, pupa, and adult) by stimulating the heart with 475 nm pulsed laser light. Heart response to stimulation pulses was monitored non-invasively with OCM. This integrated non-invasive optogenetic control and in vivo imaging technique provides a novel platform for performing research studies in developmental cardiology.

  12. Imaging arterial cells, atherosclerosis, and restenosis by multimodal nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Han-Wei; Simianu, Vlad; Locker, Matthew J.; Sturek, Michael; Cheng, Ji-Xin

    2008-02-01

    By integrating sum-frequency generation (SFG), and two-photon excitation fluorescence (TPEF) on a coherent anti-Stokes Raman scattering (CARS) microscope platform, multimodal nonlinear optical (NLO) imaging of arteries and atherosclerotic lesions was demonstrated. CARS signals arising from CH II-rich membranes allowed visualization of endothelial cells and smooth muscle cells in a carotid artery. Additionally, CARS microscopy allowed vibrational imaging of elastin and collagen fibrils which are rich in CH II bonds in their cross-linking residues. The extracellular matrix organization was further confirmed by TPEF signals arising from elastin's autofluorescence and SFG signals arising from collagen fibrils' non-centrosymmetric structure. The system is capable of identifying different atherosclerotic lesion stages with sub-cellular resolution. The stages of atherosclerosis, such as macrophage infiltration, lipid-laden foam cell accumulation, extracellular lipid distribution, fibrous tissue deposition, plaque establishment, and formation of other complicated lesions could be viewed by our multimodal CARS microscope. Collagen percentages in the region adjacent to coronary artery stents were resolved. High correlation between NLO and histology imaging evidenced the validity of the NLO imaging. The capability of imaging significant components of an arterial wall and distinctive stages of atherosclerosis in a label-free manner suggests the potential application of multimodal nonlinear optical microscopy to monitor the onset and progression of arterial diseases.

  13. Multiphoton imaging microscopy at deeper layers with adaptive optics control of spherical aberration.

    PubMed

    Bueno, Juan M; Skorsetz, Martin; Palacios, Raquel; Gualda, Emilio J; Artal, Pablo

    2014-01-01

    Despite the inherent confocality and optical sectioning capabilities of multiphoton microscopy, three-dimensional (3-D) imaging of thick samples is limited by the specimen-induced aberrations. The combination of immersion objectives and sensorless adaptive optics (AO) techniques has been suggested to overcome this difficulty. However, a complex plane-by-plane correction of aberrations is required, and its performance depends on a set of image-based merit functions. We propose here an alternative approach to increase penetration depth in 3-D multiphoton microscopy imaging. It is based on the manipulation of the spherical aberration (SA) of the incident beam with an AO device while performing fast tomographic multiphoton imaging. When inducing SA, the image quality at best focus is reduced; however, better quality images are obtained from deeper planes within the sample. This is a compromise that enables registration of improved 3-D multiphoton images using nonimmersion objectives. Examples on ocular tissues and nonbiological samples providing different types of nonlinear signal are presented. The implementation of this technique in a future clinical instrument might provide a better visualization of corneal structures in living eyes.

  14. A new method of assessing the surgical margin in rectal carcinoma—using nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Li, Lianhuang; Chen, Zhifen; Kang, Deyong; Deng, Tongxin; Jiang, Liwei; Zhou, Yi; Liu, Xing; Jiang, Weizhong; Zhuo, Shuangmu; Guan, Guoxian; Chi, Pan; Chen, Jianxin

    2016-06-01

    Nowadays, surgical resection is still the most effective treatment strategy for rectal carcinoma and one of the most important factors affecting whether the operation is successful or not is the surgical margin determination, especially in the distal rectal carcinoma which should take the sphincter-preserving issue into consideration. However, until recently no reliable evaluation method has been developed for this purpose. There are some shortcomings in intraoperative negative surgical margin assessment such as either lack of enough detailed information of biological tissues or the fact that it is time-consuming. Multiphoton microscopy (MPM)—nonlinear optical microscopy, which is based on the nonlinear optical process two-photon excited fluorescence (TPEF) and second harmonic generation (SHG), has the ability to label freely and noninvasively visualize tissue micro-architecture at the sub-cellular level. The advantage of providing high contrast and high resolution biomedical image in real time makes MPM have a wide range of applications in life sciences. In this study, we introduced MPM to identify the boundary between normal and abnormal rectal tissues. MPM images clearly exhibit biological tissue microstructure and its morphological changes in the regions of our interest, which enable it to determine the surgical margin in rectal carcinoma. It can be foreseen that once MPM imaging system is used in clinical examination, it will greatly improve the accuracy of surgical resection.

  15. Lensless fluorescent on-chip microscopy using a fiber-optic taper.

    PubMed

    Coskun, Ahmet F; Sencan, Ikbal; Su, Ting-Wei; Ozcan, Aydogan

    2011-01-01

    We demonstrate a lensfree on-chip fluorescent microscopy platform that can image fluorescently labeled cells over ~60 mm(2) field-of-view with <4 urn spatial resolution. In this lensfree imaging system, micro-objects of interest are directly located on a tapered fiber-optic faceplate which has > 5-fold higher density of fiber-optic waveguides in its top facet compared to the bottom facet. For excitation, an incoherent light source (e.g., a simple light emitting diode--LED) is used to pump fluorescent objects through a glass hemi-sphere interface. Upon interacting with the entire sample volume, the excitation light is rejected by total internal reflection process occurring at the bottom of the sample substrate. Fluorescent emission from the objects is then collected by the smaller facet of the tapered faceplate and is delivered to a detector-array with an image magnification of ~2.4X. A compressive sampling based decoding algorithm is used for sparse signal recovery, which further increases the space-bandwidth-product of our lensfree on-chip fluorescent imager. We validated the performance of this lensfree imaging platform using fluorescent micro-particles as well as labeled water-borne parasites (e.g., Giardia Muris cysts). Such a compact and wide-field fluorescent microscopy platform could be valuable for cytometry and rare cell imaging applications as well as for micro array research.

  16. Wide-field lensless fluorescent microscopy using a tapered fiber-optic faceplate on a chip.

    PubMed

    Coskun, Ahmet F; Sencan, Ikbal; Su, Ting-Wei; Ozcan, Aydogan

    2011-09-07

    We demonstrate lensless fluorescent microscopy over a large field-of-view of ~60 mm(2) with a spatial resolution of <4 µm. In this on-chip fluorescent imaging modality, the samples are placed on a fiber-optic faceplate that is tapered such that the density of the fiber-optic waveguides on the top facet is >5 fold larger than the bottom one. Placed on this tapered faceplate, the fluorescent samples are pumped from the side through a glass hemisphere interface. After excitation of the samples, the pump light is rejected through total internal reflection that occurs at the bottom facet of the sample substrate. The fluorescent emission from the sample is then collected by the smaller end of the tapered faceplate and is delivered to an opto-electronic sensor-array to be digitally sampled. Using a compressive sampling algorithm, we decode these raw lensfree images to validate the resolution (<4 µm) of this on-chip fluorescent imaging platform using microparticles as well as labeled Giardia muris cysts. This wide-field lensfree fluorescent microscopy platform, being compact and high-throughput, might provide a valuable tool especially for cytometry, rare cell analysis (involving large area microfluidic systems) as well as for microarray imaging applications.

  17. DMD-based random-access optical-resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Liang, Jinyang; Zhou, Yong; Winkler, Amy W.; Wang, Lidai; Maslov, Konstantin I.; Li, Chiye; Wang, Lihong V.

    2014-03-01

    The scanning mechanism is a major technical focus in optical-resolution photoacoustic microscopy. Flexible scanning access with fast scanning speed is desired to monitor biological and physiological dynamics with high temporal resolution. We developed random-access optical-resolution photoacoustic microscopy (RA-OR-PAM) using a digital micromirror device (DMD). Each micromirror on the DMD can be independently controlled, allowing imaging of regions of interest with arbitrary user-selected shapes without extraneous information. A global structural image is first acquired, and the regions of interest are selected. The laser beam then scans these regions exclusively, resulting in a faster frame rate than in a conventional raster scan. This system can rapidly scan arbitrarily shaped regions of interest with a lateral resolution of 3.6 μm within a 40×40 μm2 imaging area, a size comparable to the focal spot size of a 50 MHz ultrasound transducer. We demonstrated the random-access ability of RA-OR-PAM by imaging a monolayer of red blood cells. This system was then used to monitor blood flow in vivo within user-selected capillaries in a mouse ear. By imaging only the capillary of interest, the frame rate was increased by up to 13.3 times.

  18. Membrane distribution of the glycine receptor α3 studied by optical super-resolution microscopy.

    PubMed

    Notelaers, Kristof; Rocha, Susana; Paesen, Rik; Swinnen, Nina; Vangindertael, Jeroen; Meier, Jochen C; Rigo, Jean-Michel; Ameloot, Marcel; Hofkens, Johan

    2014-07-01

    In this study, the effect of glycine receptor (GlyR) α3 alternative RNA splicing on the distribution of receptors in the membrane of human embryonic kidney 293 cells is investigated using optical super-resolution microscopy. Direct stochastic optical reconstruction microscopy is used to image both α3K and α3L splice variants individually and together using single- and dual-color imaging. Pair correlation analysis is used to extract quantitative measures from the resulting images. Autocorrelation analysis of the individually expressed variants reveals clustering of both variants, yet with differing properties. The cluster size is increased for α3L compared to α3K (mean radius 92 ± 4 and 56 ± 3 nm, respectively), yet an even bigger difference is found in the cluster density (9,870 ± 1,433 and 1,747 ± 200 μm(-2), respectively). Furthermore, cross-correlation analysis revealed that upon co-expression, clusters colocalize on the same spatial scales as for individually expressed receptors (mean co-cluster radius 94 ± 6 nm). These results demonstrate that RNA splicing determines GlyR α3 membrane distribution, which has consequences for neuronal GlyR physiology and function.

  19. Label-free identification of the microstructure of rat spinal cords based on nonlinear optical microscopy.

    PubMed

    Liao, C X; Wang, Z Y; Zhou, Y; Zhou, L Q; Zhu, X Q; Liu, W G; Chen, J X

    2017-03-20

    The spinal cord is a vital link between the brain and the body and mainly comprises neurons, glial cells and nerve fibres. In this work, nonlinear optical (NLO) microscopy based on intrinsic tissue properties was employed to label-freely analyze the cells and matrix in spinal cords at a molecular level. The high-resolution and high-contrast NLO images of unstained spinal cords demonstrate that NLO microscopy has the ability to show the microstructure of white and grey matter including ventral horn, intermediate area, dorsal horns, ventral column, lateral column and dorsal column. Neurons with various sizes were identified in grey matter by dark spots of nonfluorescent nuclei encircled by cytoplasm-emitting two-photon excited fluorescence signals. Nerve fibres and neuroglias were observed in white matter. Besides, the spinal arteries were clearly presented by NLO microscopy. Using spectral and morphological information, this technique was proved to be an effective tool for label-freely imaging spinal cord tissues, based on endogenous signals in biological tissue. With future development, we foresee promising applications of the NLO technique for in vivo, real-time assessment of spinal cord diseases or injures.

  20. Development of a Fiber Laser with Independently Adjustable Properties for Optical Resolution Photoacoustic Microscopy.

    PubMed

    Aytac-Kipergil, Esra; Demirkiran, Aytac; Uluc, Nasire; Yavas, Seydi; Kayikcioglu, Tunc; Salman, Sarper; Karamuk, Sohret Gorkem; Ilday, Fatih Omer; Unlu, Mehmet Burcin

    2016-12-08

    Photoacoustic imaging is based on the detection of generated acoustic waves through thermal expansion of tissue illuminated by short laser pulses. Fiber lasers as an excitation source for photoacoustic imaging have recently been preferred for their high repetition frequencies. Here, we report a unique fiber laser developed specifically for multiwavelength photoacoustic microscopy system. The laser is custom-made for maximum flexibility in adjustment of its parameters; pulse duration (5-10 ns), pulse energy (up to 10 μJ) and repetition frequency (up to 1 MHz) independently from each other and covers a broad spectral region from 450 to 1100 nm and also can emit wavelengths of 532, 355, and 266 nm. The laser system consists of a master oscillator power amplifier, seeding two stages; supercontinuum and harmonic generation units. The laser is outstanding since the oscillator, amplifier and supercontinuum generation parts are all-fiber integrated with custom-developed electronics and software. To demonstrate the feasibility of the system, the images of several elements of standardized resolution test chart are acquired at multiple wavelengths. The lateral resolution of optical resolution photoacoustic microscopy system is determined as 2.68 μm. The developed system may pave the way for spectroscopic photoacoustic microscopy applications via widely tunable fiber laser technologies.

  1. Development of a Fiber Laser with Independently Adjustable Properties for Optical Resolution Photoacoustic Microscopy

    PubMed Central

    Aytac-Kipergil, Esra; Demirkiran, Aytac; Uluc, Nasire; Yavas, Seydi; Kayikcioglu, Tunc; Salman, Sarper; Karamuk, Sohret Gorkem; Ilday, Fatih Omer; Unlu, Mehmet Burcin

    2016-01-01

    Photoacoustic imaging is based on the detection of generated acoustic waves through thermal expansion of tissue illuminated by short laser pulses. Fiber lasers as an excitation source for photoacoustic imaging have recently been preferred for their high repetition frequencies. Here, we report a unique fiber laser developed specifically for multiwavelength photoacoustic microscopy system. The laser is custom-made for maximum flexibility in adjustment of its parameters; pulse duration (5–10 ns), pulse energy (up to 10 μJ) and repetition frequency (up to 1 MHz) independently from each other and covers a broad spectral region from 450 to 1100 nm and also can emit wavelengths of 532, 355, and 266 nm. The laser system consists of a master oscillator power amplifier, seeding two stages; supercontinuum and harmonic generation units. The laser is outstanding since the oscillator, amplifier and supercontinuum generation parts are all-fiber integrated with custom-developed electronics and software. To demonstrate the feasibility of the system, the images of several elements of standardized resolution test chart are acquired at multiple wavelengths. The lateral resolution of optical resolution photoacoustic microscopy system is determined as 2.68 μm. The developed system may pave the way for spectroscopic photoacoustic microscopy applications via widely tunable fiber laser technologies. PMID:27929049

  2. Comparing Fourier optics and contrast transfer function modeling of image formation in low energy electron microscopy.

    PubMed

    Yu, K M; Locatelli, A; Altman, M S

    2017-03-24

    A theoretical understanding of image formation in cathode lens microscopy can facilitate image interpretation. We compare Fourier Optics (FO) and Contrast Transfer Function (CTF) approaches that were recently adapted from other realms of microscopy to model image formation in low energy electron microscopy (LEEM). Although these two approaches incorporate imaging errors from several sources similarly, they differ in the way that the image intensity is calculated. The simplification that is used in the CTF calculation advantageously leads to its computational efficiency. However, we find that lens aberrations, and spatial and temporal coherence may affect the validity of the CTF approach to model LEEM image formation under certain conditions. In particular, these effects depend strongly on the nature of the object being imaged and also become more pronounced with increasing defocus. While the use of the CTF approach appears to be justified for objects that are routinely imaged with LEEM, comparison of theory to experimental observations of a focal image series for rippled, suspended graphene reveals one example where FO works, but CTF does not. This work alerts us to potential pitfalls and guides the effective use of FO and CTF approaches. It also lays the foundation for quantitative image evaluation using these methods.

  3. High Resolution Imaging of Polymers Using Stochastic Optical Reconstruction Microscopy (STORM)

    NASA Astrophysics Data System (ADS)

    Gramlich, M. W.; Bae, J.; Hayward, R.; Ross, J. L.

    2013-03-01

    Recent super-resolution fluorescence imaging techniques represent attractive new methods for structural characterization of polymeric systems. STORM is a technique developed over the last decade to image structure and dynamics in biological systems. The high spatial resolution approaches that of other well-established techniques, such as atomic force microscopy (AFM) or scanning electron microscopy, but with all the advantages of a far-field optical technique. We have adapted STORM imaging techniques to polymeric materials, specifically using thin film blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) as a model system. We labeled PMMA with Alexa-647 fluorescent dye, and combined 10wt% label to un-labeled PMMA, then prepared 50:50 by weight blends with PS. We find the lateral PMMA domain size increases with film thickness. Furthermore, we show that the structure and size of the domains is equivalent to results from AFM. Funding is acknowledged from NSF MRI grant#DBI-0923318 to Ross and Wadsworth, ``Development of FPALM-STORM for Live Cell Single Molecule Microscopy'' NSF MRSEC grant #DMR-0820506 to UMass. We would like to acknowledge Rachel Letteri, Brent Hammer, Todd Emrick, Weiyin Gu, and Tom Russell for help with material preparation.

  4. Mapping optical path length and image enhancement using quantitative orientation-independent differential interference contrast microscopy

    NASA Astrophysics Data System (ADS)

    Shribak, Michael; Larkin, Kieran G.; Biggs, David

    2017-01-01

    We describe the principles of using orientation-independent differential interference contrast (OI-DIC) microscopy for mapping optical path length (OPL). Computation of the scalar two-dimensional OPL map is based on an experimentally received map of the OPL gradient vector field. Two methods of contrast enhancement for the OPL image, which reveal hardly visible structures and organelles, are presented. The results obtained can be used for reconstruction of a volume image. We have confirmed that a standard research grade light microscope equipped with the OI-DIC and 100×/1.3 NA objective lens, which was not specially selected for minimum wavefront and polarization aberrations, provides OPL noise level of ˜0.5 nm and lateral resolution if ˜300 nm at a wavelength of 546 nm. The new technology is the next step in the development of the DIC microscopy. It can replace standard DIC prisms on existing commercial microscope systems without modification. This will allow biological researchers that already have microscopy setups to expand the performance of their systems.

  5. Development of a Fiber Laser with Independently Adjustable Properties for Optical Resolution Photoacoustic Microscopy

    NASA Astrophysics Data System (ADS)

    Aytac-Kipergil, Esra; Demirkiran, Aytac; Uluc, Nasire; Yavas, Seydi; Kayikcioglu, Tunc; Salman, Sarper; Karamuk, Sohret Gorkem; Ilday, Fatih Omer; Unlu, Mehmet Burcin

    2016-12-01

    Photoacoustic imaging is based on the detection of generated acoustic waves through thermal expansion of tissue illuminated by short laser pulses. Fiber lasers as an excitation source for photoacoustic imaging have recently been preferred for their high repetition frequencies. Here, we report a unique fiber laser developed specifically for multiwavelength photoacoustic microscopy system. The laser is custom-made for maximum flexibility in adjustment of its parameters; pulse duration (5–10 ns), pulse energy (up to 10 μJ) and repetition frequency (up to 1 MHz) independently from each other and covers a broad spectral region from 450 to 1100 nm and also can emit wavelengths of 532, 355, and 266 nm. The laser system consists of a master oscillator power amplifier, seeding two stages; supercontinuum and harmonic generation units. The laser is outstanding since the oscillator, amplifier and supercontinuum generation parts are all-fiber integrated with custom-developed electronics and software. To demonstrate the feasibility of the system, the images of several elements of standardized resolution test chart are acquired at multiple wavelengths. The lateral resolution of optical resolution photoacoustic microscopy system is determined as 2.68 μm. The developed system may pave the way for spectroscopic photoacoustic microscopy applications via widely tunable fiber laser technologies.

  6. Multiscale roughness in optical multilayers: atomic force microscopy and light scattering.

    PubMed

    Deumié, C; Richier, R; Dumas, P; Amra, C

    1996-10-01

    We have previously shown that macroscopic roughness spectra measured with light scattering at visible wavelengths were perfectly extrapolated at high spatial frequencies by microscopic roughness spectra measured with atomic force microscopy [Europhys. Lett. 22, 717 (1993); Proc. SPIE 2253, 614 (1994)]. These results have been confirmed by numerous experiments [Proc. SPIE 2253, 614 (1994)] and allow us today to characterize thin films microstructure from a macroscopic to a microscopic scale. In the first step the comparison of light scattering and atomic force microscopy is completed by optical measurements at UV wavelengths that allow us to superimpose (and no longer extrapolate) the spectra measured by the two techniques. In the second step we extract multiscale parameters that describe the action of thin-film coatings on substrate roughness in all bandwidths. The results obviously depend on materials and substrates and deposition techniques. Electron-beam evaporation, ion-assisted deposition, and ion plating are compared, and the conclusions are discussed in regard to the deposition parameters. Finally, special attention is given to the limits and performances of the two characterization techniques (light scattering and atomic force microscopy) that may be sensitive to different phenomena.

  7. Multiphoton microscopy, fluorescence lifetime imaging and optical spectroscopy for the diagnosis of neoplasia

    NASA Astrophysics Data System (ADS)

    Skala, Melissa Caroline

    2007-12-01

    Cancer morbidity and mortality is greatly reduced when the disease is diagnosed and treated early in its development. Tissue biopsies are the gold standard for cancer diagnosis, and an accurate diagnosis requires a biopsy from the malignant portion of an organ. Light, guided through a fiber optic probe, could be used to inspect regions of interest and provide real-time feedback to determine the optimal tissue site for biopsy. This approach could increase the diagnostic accuracy of current biopsy procedures. The studies in this thesis have characterized changes in tissue optical signals with carcinogenesis, increasing our understanding of the sensitivity of optical techniques for cancer detection. All in vivo studies were conducted on the dimethylbenz[alpha]anthracene treated hamster cheek pouch model of epithelial carcinogenesis. Multiphoton microscopy studies in the near infrared wavelength region quantified changes in tissue morphology and fluorescence with carcinogenesis in vivo. Statistically significant morphological changes with precancer included increased epithelial thickness, loss of stratification in the epithelium, and increased nuclear diameter. Fluorescence changes included a statistically significant decrease in the epithelial fluorescence intensity per voxel at 780 nm excitation, a decrease in the fluorescence lifetime of protein-bound nicotinamide adenine dinucleotide (NADH, an electron donor in oxidative phosphorylation), and an increase in the fluorescence lifetime of protein-bound flavin adenine dinucleotide (FAD, an electron acceptor in oxidative phosphorylation) with precancer. The redox ratio (fluorescence intensity of FAD/NADH, a measure of the cellular oxidation-reduction state) did not significantly change with precancer. Cell culture experiments (MCF10A cells) indicated that the decrease in protein-bound NADH with precancer could be due to increased levels of glycolysis. Point measurements of diffuse reflectance and fluorescence spectra in

  8. Optical and mechanical detection of near-field light by atomic force microscopy using a piezoelectric cantilever

    NASA Astrophysics Data System (ADS)

    Satoh, Nobuo; Kobayashi, Kei; Watanabe, Shunji; Fujii, Toru; Matsushige, Kazumi; Yamada, Hirofumi

    2016-08-01

    In this study, we developed an atomic force microscopy (AFM) system with scanning near-field optical microscopy (SNOM) using a microfabricated force-sensing cantilever with a lead zirconate titanate (PZT) thin film. Both optical and mechanical detection techniques were adopted in SNOM to detect scattered light induced by the interaction of the PZT cantilever tip apex and evanescent light, and SNOM images were obtained for each detection scheme. The mechanical detection technique did allow for a clear observation of the light scattered from the PZT cantilever without the interference observed by the optical detection technique, which used an objective lens, a pinhole, and a photomultiplier tube.

  9. Water cooled metal optics for the Advanced Light Source

    SciTech Connect

    McKinney, W.R.; Irick, S.C.; Lunt, D.L.J.

    1991-10-28

    The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.

  10. Dictionary of Microscopy

    NASA Astrophysics Data System (ADS)

    Heath, Julian

    2005-10-01

    The past decade has seen huge advances in the application of microscopy in all areas of science. This welcome development in microscopy has been paralleled by an expansion of the vocabulary of technical terms used in microscopy: terms have been coined for new instruments and techniques and, as microscopes reach even higher resolution, the use of terms that relate to the optical and physical principles underpinning microscopy is now commonplace. The Dictionary of Microscopy was compiled to meet this challenge and provides concise definitions of over 2,500 terms used in the fields of light microscopy, electron microscopy, scanning probe microscopy, x-ray microscopy and related techniques. Written by Dr Julian P. Heath, Editor of Microscopy and Analysis, the dictionary is intended to provide easy navigation through the microscopy terminology and to be a first point of reference for definitions of new and established terms. The Dictionary of Microscopy is an essential, accessible resource for: students who are new to the field and are learning about microscopes equipment purchasers who want an explanation of the terms used in manufacturers' literature scientists who are considering using a new microscopical technique experienced microscopists as an aide mémoire or quick source of reference librarians, the press and marketing personnel who require definitions for technical reports.

  11. Optical metrology for advanced process control: full module metrology solutions

    NASA Astrophysics Data System (ADS)

    Bozdog, Cornel; Turovets, Igor

    2016-03-01

    Optical metrology is the workhorse metrology in manufacturing and key enabler to patterning process control. Recent advances in device architecture are gradually shifting the need for process control from the lithography module to other patterning processes (etch, trim, clean, LER/LWR treatments, etc..). Complex multi-patterning integration solutions, where the final pattern is the result of multiple process steps require a step-by-step holistic process control and a uniformly accurate holistic metrology solution for pattern transfer for the entire module. For effective process control, more process "knobs" are needed, and a tighter integration of metrology with process architecture.

  12. TOPICAL REVIEW: Recent advances in diffuse optical imaging

    NASA Astrophysics Data System (ADS)

    Gibson, A. P.; Hebden, J. C.; Arridge, S. R.

    2005-02-01

    We review the current state-of-the-art of diffuse optical imaging, which is an emerging technique for functional imaging of biological tissue. It involves generating images using measurements of visible or near-infrared light scattered across large (greater than several centimetres) thicknesses of tissue. We discuss recent advances in experimental methods and instrumentation, and examine new theoretical techniques applied to modelling and image reconstruction. We review recent work on in vivo applications including imaging the breast and brain, and examine future challenges.

  13. Sensitivity and Specificity of Cardiac Tissue Discrimination Using Fiber-Optics Confocal Microscopy

    PubMed Central

    Huang, Chao; Sachse, Frank B.; Hitchcock, Robert W.; Kaza, Aditya K.

    2016-01-01

    Disturbances of the cardiac conduction system constitute a major risk after surgical repair of complex cases of congenital heart disease. Intraoperative identification of the conduction system may reduce the incidence of these disturbances. We previously developed an approach to identify cardiac tissue types using fiber-optics confocal microscopy and extracellular fluorophores. Here, we applied this approach to investigate sensitivity and specificity of human and automated classification in discriminating images of atrial working myocardium and specialized tissue of the conduction system. Two-dimensional image sequences from atrial working myocardium and nodal tissue of isolated perfused rodent hearts were acquired using a fiber-optics confocal microscope (Leica FCM1000). We compared two methods for local application of extracellular fluorophores: topical via pipette and with a dye carrier. Eight blinded examiners evaluated 162 randomly selected images of atrial working myocardium (n = 81) and nodal tissue (n = 81). In addition, we evaluated the images using automated classification. Blinded examiners achieved a sensitivity and specificity of 99.2±0.3% and 98.0±0.7%, respectively, with the dye carrier method of dye application. Sensitivity and specificity was similar for dye application via a pipette (99.2±0.3% and 94.0±2.4%, respectively). Sensitivity and specificity for automated methods of tissue discrimination were similarly high. Human and automated classification achieved high sensitivity and specificity in discriminating atrial working myocardium and nodal tissue. We suggest that our findings facilitate clinical translation of fiber-optics confocal microscopy as an intraoperative imaging modality to reduce the incidence of conduction disturbances during surgical correction of congenital heart disease. PMID:26808149

  14. Sensitivity and Specificity of Cardiac Tissue Discrimination Using Fiber-Optics Confocal Microscopy.

    PubMed

    Huang, Chao; Sachse, Frank B; Hitchcock, Robert W; Kaza, Aditya K

    2016-01-01

    Disturbances of the cardiac conduction system constitute a major risk after surgical repair of complex cases of congenital heart disease. Intraoperative identification of the conduction system may reduce the incidence of these disturbances. We previously developed an approach to identify cardiac tissue types using fiber-optics confocal microscopy and extracellular fluorophores. Here, we applied this approach to investigate sensitivity and specificity of human and automated classification in discriminating images of atrial working myocardium and specialized tissue of the conduction system. Two-dimensional image sequences from atrial working myocardium and nodal tissue of isolated perfused rodent hearts were acquired using a fiber-optics confocal microscope (Leica FCM1000). We compared two methods for local application of extracellular fluorophores: topical via pipette and with a dye carrier. Eight blinded examiners evaluated 162 randomly selected images of atrial working myocardium (n = 81) and nodal tissue (n = 81). In addition, we evaluated the images using automated classification. Blinded examiners achieved a sensitivity and specificity of 99.2 ± 0.3% and 98.0 ± 0.7%, respectively, with the dye carrier method of dye application. Sensitivity and specificity was similar for dye application via a pipette (99.2 ± 0.3% and 94.0 ± 2.4%, respectively). Sensitivity and specificity for automated methods of tissue discrimination were similarly high. Human and automated classification achieved high sensitivity and specificity in discriminating atrial working myocardium and nodal tissue. We suggest that our findings facilitate clinical translation of fiber-optics confocal microscopy as an intraoperative imaging modality to reduce the incidence of conduction disturbances during surgical correction of congenital heart disease.

  15. Combination of an optical parametric oscillator and quantum-dots 655 to improve imaging depth of vasculature by intravital multicolor two-photon microscopy.

    PubMed

    Ricard, Clément; Lamasse, Lisa; Jaouen, Alexandre; Rougon, Geneviève; Debarbieux, Franck

    2016-06-01

    Simultaneous imaging of different cell types and structures in the mouse central nervous system (CNS) by intravital two-photon microscopy requires the characterization of fluorophores and advances in approaches to visualize them. We describe the use of a two-photon infrared illumination generated by an optical parametric oscillator (OPO) on quantum-dots 655 (QD655) nanocrystals to improve resolution of the vasculature deeper in the mouse brain both in healthy and pathological conditions. Moreover, QD655 signal can be unmixed from the DsRed2, CFP, EGFP and EYFP fluorescent proteins, which enhances the panel of multi-parametric correlative investigations both in the cortex and the spinal cord.

  16. Optical resolution photoacoustic microscopy using a Blu-ray DVD pickup head

    NASA Astrophysics Data System (ADS)

    Li, Meng-Lin; Wang, Po-Hsun

    2014-03-01

    Optical resolution photoacoustic microscopy (OR-PAM) has been shown as a promising tool for label-free microvascular and single-cell imaging in clinical and bioscientific applications. However, most OR-PAM systems are realized by using a bulky laser for photoacoustic excitation. The large volume and high price of the laser may restrain the popularity of OR-PAM. In this study, we attempt to develop a compact, portable, and low cost OR-PAM based on a consumer Blu-ray (405 nm) DVD pickup head for label-free micro-vascular imaging and red-blood-cell related blood examination. According to the high optical absorption of the hemoglobin at 405 nm, the proposed OR-PAM has potential to be an alternative for the conventional optical microscopy in the examinations of hematological morphology for blood routine. We showed that the Blu-ray DVD pickup head owns the required laser energy and focusing optics for OR-PAM. The firmware of a Blu-ray DVD drive was modified to allow its pickup head to generate nano-second laser pulses with a tunable pulse repetition rate of >30 kHz and a tunable pulse width ranging from 10 to 30 ns. The laser beam was focused onto the target after passing through a transparent cover slide, and then aligned to be confocal with a 50-MHz focused ultrasonic transducer in forward mode. To keep the target on focus, a scan involving auto-tracking procedure was performed. The measured maximum achievable lateral resolution was 1 μm which was mainly limited by the minimum step size of the used motorized stage. A blood smear was imaged without any staining. The red blood cells were well resolved and the biconcave structure could be clearly visualized. In addition, to verify the in vivo imaging capability of the proposed OR-PAM, the micro-vasculature of a mouse ear was imaged without any contrast agent. The results showed that it performed better than a 200x digital optical microscope in terms of image contrast and vascular morphology. In summaries, the proposed OR

  17. Modeling optical behavior of birefringent biological tissues for evaluation of quantitative polarized light microscopy

    NASA Astrophysics Data System (ADS)

    van Turnhout, Mark C.; Kranenbarg, Sander; van Leeuwen, Johan L.

    2009-09-01

    Quantitative polarized light microscopy (qPLM) is a popular tool for the investigation of birefringent architectures in biological tissues. Collagen, the most abundant protein in mammals, is such a birefringent material. Interpretation of results of qPLM in terms of collagen network architecture and anisotropy is challenging, because different collagen networks may yield equal qPLM results. We created a model and used the linear optical behavior of collagen to construct a Jones or Mueller matrix for a histological cartilage section in an optical qPLM train. Histological sections of tendon were used to validate the basic assumption of the model. Results show that information on collagen densities is needed for the interpretation of qPLM results in terms of collagen anisotropy. A parameter that is independent of the optical system and that measures collagen fiber anisotropy is introduced, and its physical interpretation is discussed. With our results, we can quantify which part of different qPLM results is due to differences in collagen densities and which part is due to changes in the collagen network. Because collagen fiber orientation and anisotropy are important for tissue function, these results can improve the biological and medical relevance of qPLM results.

  18. Comparison of rotational imaging optical coherence tomography and selective plane illumination microscopy for embryonic study

    NASA Astrophysics Data System (ADS)

    Wu, Chen; Ran, Shihao; Le, Henry H.; Singh, Manmohan; Larina, Irina V.; Mayerich, David; Dickinson, Mary E.; Larin, Kirill V.

    2016-03-01

    The mouse is a common model for studying developmental diseases. Different optical techniques have been developed to investigate mouse embryos, but each has its own set of limitations and restrictions. In this study, we imaged the same E9.5 mouse embryo with rotational imaging Optical Coherence Tomography (RI-OCT) and Selective Plane Illumination Microscopy (SPIM), and compared the two techniques. Results demonstrate that both methods can provide images with micrometer-scale spatial resolution. The RI-OCT technique was developed to increase imaging depth of OCT by performing traditional OCT imaging at multiple sides and co-registering the images. In SPIM, optical sectioning is achieved by illuminating the sample with a sheet of light. In this study, the images acquired from both techniques are compared with each other to evaluate the benefits and drawbacks of each technique for embryonic imaging. Since 3D stacks can be obtained by SPIM from different angles by rotating the sample, it might be possible to build a hybrid setup of two imaging modalities to combine the advantages of each technique.

  19. Optically stabilized mercury short-arc lamp as UV light source for microscopy

    NASA Astrophysics Data System (ADS)

    Heynen, Susanne; Gough, David A.; Price, Jeffrey H.

    1997-05-01

    For certain applications in microscopy, mercury vapor short arc lamps are utilized as UV-light sources because of their high intensity and their road spectrum. Unfortunately, they are also very unstable. Especially for single wavelength fluorescence image cytometry, there is a need for a stable, high intensity light source. Substantially improved stability was achieved using optical feedback and fiberoptic scrambling. The system uses a photodiode to monitor the light intensity, and feeds the readout back to a controller. The controller compares this readout to a preset reference voltage and adjusts the lamp supply current accordingly. The optical fiber scrambles the light to correct the effects of arc wander. Preliminary results of performance tests of this system show a coefficient of variation (CV) of less than 0.1 percent over 20 hours at a sample frequency of 30 Hz. This CV is a factor of 30 better than a conventional current stabilized mercy vapor short arc lamp. Scrambled optical feedback is a necessary addition for systems with mercury short arc lamps, especially for image fluorometry applications.

  20. Ultrathin forward-imaging short multimode fiber probe for full-field optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Sato, Manabu; Saito, Daisuke; Shouji, Kou; Kurotani, Reiko; Abe, Hiroyuki; Nishidate, Izumi

    2016-12-01

    To extend the applications of optical coherence tomography (OCT) to the fields of physiology and clinical medicine, less invasive, robust, and reliable optical probes are required. Thus, we demonstrate an ultrathin forward-imaging short multimode fiber (SMMF) optical coherence microscopy (OCM) probe with a 50 μm core diameter, 125 μm total diameter, and 5.12 mm length. Imaging conditions and magnification were analyzed, and they correspond closely to the measured results. The dispersion of the SMMF was investigated, and the modal dispersion coefficient was found to be 2.3% of the material dispersion coefficient. The axial resolution was minimized at 2.15 μm using a 0.885-mm-thick dispersion compensator. The lateral resolution was evaluated to be 4.38 μm using a test pattern. The contrast of the OCM images was 5.7 times higher than that of the signal images owing to the coherence gate. The depth of focus and diameter of the field of view were measured to be 60 μm and 40-50 μm, respectively. OCM images of the dried fins of small fish (Medaka) were measured and internal structures could be recognized.

  1. Live endothelial cells imaged by Scanning Near-field Optical Microscopy (SNOM): capabilities and challenges.

    PubMed

    Bulat, Katarzyna; Rygula, Anna; Szafraniec, Ewelina; Ozaki, Yukihiro; Baranska, Malgorzata

    2016-08-22

    The scanning near-field optical microscopy (SNOM) shows a potential to study details of biological samples, since it provides the optical images of objects with nanometric spatial resolution (50-200 nm) and the topographic information at the same time. The goal of this work is to demonstrate the capabilities of SNOM in transmission configuration to study human endothelial cells and their morphological changes, sometimes very subtle, upon inflammation. Various sample preparations were tested for SNOM measurements and promising results are collected to show: 1) the influence of α tumor necrosis factor (TNF-α) on EA.hy 926 cells (measurements of the fixed cells); 2) high resolution images of various endothelial cell lines, i.e. EA.hy 926 and HLMVEC (investigations of the fixed cells in buffer environment); 3) imaging of live endothelial cells in physiological buffers. The study demonstrate complementarity of the SNOM measurements performed in air and in liquid environments, on fixed as well as on living cells. Furthermore, it is proved that the SNOM is a very useful method for analysis of cellular morphology and topography. Changes in the cell shape and nucleus size, which are the symptoms of inflammatory reaction, were noticed in TNF-α activated EA.hy 926 cells. The cellular structures of submicron size were observed in high resolution optical images of cells from EA.hy 926 and HLMVEC lines.

  2. A transparent broadband ultrasonic detector based on an optical micro-ring resonator for photoacoustic microscopy

    PubMed Central

    Li, Hao; Dong, Biqin; Zhang, Zhen; Zhang, Hao F.; Sun, Cheng

    2014-01-01

    Photoacoustic microscopy (PAM) does not rely on contrast agent to image the optical absorption contrast in biological tissue. It is uniquely suited for measuring several tissue physiological parameters, such as hemoglobin oxygen saturation, that would otherwise remain challenging. Researchers are designing new clinical diagnostic tools and multimodal microscopic systems around PAM to fully unleash its potential. However, the sizeable and opaque piezoelectric ultrasonic detectors commonly used in PAM impose a serious constraint. Our solution is a coverslip-style optically transparent ultrasound detector based on a polymeric optical micro-ring resonator (MRR) with a total thickness of 250 μm. It enables highly-sensitive ultrasound detection over a wide receiving angle with a bandwidth of 140 MHz, which corresponds to a photoacoustic saturation limit of 287 cm−1, at an estimated noise-equivalent pressure (NEP) of 6.8 Pa. We also established a theoretical framework for designing and optimizing the MRR for PAM. PMID:24675547

  3. In vivo functional chronic imaging of a small animal model using optical-resolution photoacoustic microscopy

    PubMed Central

    Hu, Song; Maslov, Konstantin; Wang, Lihong V.

    2009-01-01

    Optical-resolution photoacoustic microscopy (OR-PAM) has been validated as a valuable tool for label-free volumetric microvascular imaging. More importantly, the advantages of noninvasiveness and measurement consistency suggest the use of OR-PAM for chronic imaging of intact microcirculation. Here, such chronic imaging is demonstrated for the first time by monitoring the healing process of laser-induced microvascular lesions in a small animal model in vivo. The central part of a 1 mm by 1 mm region in a nude mouse ear was treated under a continuous-wave laser to create a microvascular lesion for chronic study. The region of interest was imaged before the laser treatment, immediately after the treatment, and throughout the healing process using both the authors’ OR-PAM system and a commercial transmission-mode optical microscope. Three-dimensional microvascular morphology and blood oxygenation information were imaged simultaneously at capillary-level resolution. Transmission-mode optical microscopic images were acquired for comparison. OR-PAM has potential important applications in microcirculatory physiology or pathophysiology, tumor angiogenesis, laser microsurgery, and neuroscience. PMID:19610320

  4. Processing and failure studies of advanced composites using x-ray tomographic microscopy (XTM)

    SciTech Connect

    Kinney, J.H.; Saroyan, R.A.; Celeste, J. ); Nichols, M.C. ); Stock, S.R.; Breunig, T.M.; Guviniler, A. )

    1991-02-01

    The traditional role of Non-Destructive Testing (NDT) has been to identify critical flaws in components after they have been fabricated. Recently, efforts have been made to introduce NDT techniques earlier in the engineering cycle, and some progress has been made in applying NDT inspection during component processing. Improvements that have been made in the spatial resolution and sensitivity of x-ray computed tomography (CT), however, indicate that it is now possible to introduce NDT concepts and methods to the earliest stage of component manufacture, namely, in the development of new materials -- where the characterization and analysis of microscopic features are important. X-ray tomographic microscopy (XTM) is a high resolution, three-dimensional variant of CT with a spatial resolution better than 0.005 mm. These studies have demonstrated that XTM is a powerful NDT technique which is capable of imaging microstructural features in even the most complicated advanced composite materials. Work is in progress to use XTM for dynamic studies of chemical vapor infiltration in continuous fiber ceramic composites. Furthermore, an in-situ tensile load frame is now being used in conjunction with XTM to study fatigue crack growth and tensile failure in metal matrix composites. The application of NDT imaging methods to materials studies will greatly enhance our understanding of time-dependent behavior in complex engineering materials. 3 refs.

  5. Advanced electron microscopy characterization of tri-layer rare-earth oxide superlattices

    NASA Astrophysics Data System (ADS)

    Phillips, Patrick; Disa, Ankit; Ismail-Beigi, Sohrab; Klie, Robert; University of Illinois-Chicago Team; Yale University Team

    2015-03-01

    Rare-earth nickelates are known to display complex electronic and magnetic behaviors owed to a very localized and sensitive Ni-site atomic and electronic structure. Toward realizing the goal of manipulating of the energetic ordering of Ni d orbitals and 2D conduction, the present work focuses on the experimental characterization of thin film superlattice structures consisting of alternating layers of LaTiO3 and LaNiO3 sandwiched between a dull insulator, LaAlO3. Using advanced scanning transmission electron microscopy (STEM)-based methods, properties such as interfacial sharpness, electron transfer, O presence, and local electronic structure can be probed at the atomic scale, and will be discussed at length. By combining both energy dispersive X-ray (EDX) and electronic energy loss (EEL) spectroscopies in an aberration-corrected STEM, it is possible to attain energy and spatial resolutions of 0.35 eV and 100 pm, respectively. Focus of the talk will remain not only on the aforementioned properties, but will also include details and parameters of the acquisitions to facilitate future characterization at this level.

  6. Developing and Incorporating Instructional Videos and Quizzes as a Blended and Online Learning Component in an Undergraduate Optical Microscopy Curriculum.

    NASA Astrophysics Data System (ADS)

    Tramontano, S.; Gualda, G. A. R.; Claiborne, L. L.; Brame, C.

    2015-12-01

    Optical mineralogy is not an easy skill to master as an undergraduate, but it is crucial for understanding what the Earth is made out of. It is a supplementary and specific skillset typically taught in a microscope lab supporting lessons on crystallography, chemistry and mineral analysis in the classroom. Mastering the basic skills is required for advancement in courses that utilize thin sections in teaching igneous, metamorphic, and sedimentary rocks. This project asks: Will exposing undergraduate Earth and environmental studies students to optical microscopy figures in videos prior to lab assist in the acquisition of skills required to describe and distinguish Earth materials? This project is conducted in conjunction with the Blended and Online Learning Design (BOLD) Fellowship offered through the Center for Teaching (CFT) at Vanderbilt University. Eight videos and accompanying pre-lab questions were hosted online weekly in a semester-long, undergraduate Earth materials course. The focus of the design of the videos and supporting questions is specifically on microscopy skills rather than on optics concepts, which is taught post-video. The videos were made available prior to a weekly lab with the intent of familiarizing the student with the types of images and information he/she should obtain with the microscope. Multiple choice, formative-style questions accompany the videos in an online-hosted assignment. These questions are graded on basis of completion and are intended to aid in student metacognition. Subjects include students in the Vanderbilt University Earth Materials course and students from the Hanover College Mineralogy course. The effectiveness of the videos is assessed in two parts: (1) Comparing the homework and lab final grades of the students this year with those of the students last year (2) Analysis of a weekly questionnaire. The answers after each week will be compiled and compared. Collecting data from Vanderbilt University students and Hanover

  7. Understanding Alterations in Cell Nano-architecture during Early Carcinogenesis using Optical Microscopy

    NASA Astrophysics Data System (ADS)

    Damania, Dhwanil

    Carcinogenesis is a complex multi-step process which eventually results in a malignant phenotype that often progresses into a fatal metastatic stage. There are several molecular changes (e.g. DNA methylation, activation of proto-oncogenes, loss of tumor-suppressor genes, histone acetylation) that occur in cells prior to the microscopically detectable morphological alterations. Hence, it is intuitive that these molecular changes should impact various biochemical, biophysical and transport processes within the cell and therefore its nanoscale morphology. Furthermore, recent studies have established that apparently `normal' cells (i.e., away from the actual tumor location) undergo similar genetic/epigenetic changes as the actual cancer cells, giving rise to the phenomenon of field carcinogenesis. Unfortunately, traditional microscopy or histopathology cannot resolve structures below 300 nm due to diffraction-limited resolution. Hence, we developed a novel optical imaging technique, partial wave spectroscopic (PWS) microscopy or optical nanocytology which quantifies the nanoscale refractive-index fluctuations (i.e. mass-density variations such as chromatin compaction) in an optically measured biomarker, disorder strength (Ld). This dissertation proves the nanoscale sensitivity of PWS nanocytology and shows that increase in Ld parallels neoplastic potential of a cell by using standardized cell-lines and animal-models. Based on concept of field carcinogenesis, we employ PWS nanocytology in a multi-center clinical study on approximately 450 patients in four different cancer-types (colon, ovarian, thyroid and lung) and we illustrate that nanoscale disorder increase is a ubiquitous phenomenon across different organs. We further demonstrate the potential of PWS nanocytology in predicting risk for developing future neoplasia. Biologically, we prove that cytoskeletal organization in both nucleus and cytoplasm plays a crucial role in governing L d-differences. Moreover, we

  8. Advances in optics in the medieval Islamic world

    NASA Astrophysics Data System (ADS)

    Al-Khalili, Jim

    2015-04-01

    This paper reviews the state of knowledge in the field of optics, mainly in catoptrics and dioptrics, before the birth of modern science and the well-documented contributions of men such as Kepler and Newton. The paper is not intended to be a comprehensive survey of the subject such as one might find in history of science journals; instead, it is aimed at the curious physicist who has probably been taught that nothing much of note was understood about the behaviour of light, beyond outdated philosophical musings, prior to the seventeenth century. The paper will focus on advances during the medieval period between the ninth and fourteenth centuries, in both the east and the west, when the theories of the Ancient Greeks were tested, advanced, corrected and mathematised. In particular, it concentrates on a multivolume treatise on optics written one thousand years ago by the Arab scholar, Ibn al-Haytham, and examines how it influenced our understanding of the nature of reflection and refraction of light. Even the well-informed physicist should find a few surprises here, which will alter his or her view of the debt we owe to these forgotten scholars.

  9. Applications of all optical signal processing for advanced optical modulation formats

    NASA Astrophysics Data System (ADS)

    Nuccio, Scott R.

    Increased data traffic demands, along with a continual push to minimize cost per bit, have recently motivated a paradigm shift away from traditional on-off keying (OOK) fiber transmission links towards systems utilizing more advanced modulation formats. In particular, modulation formats that utilize the phase of the optical signal, including differential phase shift keying (DPSK) and differential quadrature phase shift keying (DQPSK) along with polarization multiplexing (Pol-MUX), have recently emerged as the most popular means for transmitting information over long-haul and ultra-long haul fiber transmission systems. DPSK is motivated by an increase in receiver sensitivity compared to traditional OOK. DQPSK is motivated by a doubling of the spectral efficiency, along with increased tolerance to dispersion and nonlinear distortions. Coherent communications has also emerged as a primary means of transmitting and receiving optical data due to its support of formats that utilize both phase and amplitude to further increase the spectral efficiency (bits/sec/Hz) of the optical channel, including quadrature amplitude modulation (QAM). Polarization multiplexing of channels is a straight forward method to allow two channels to share the same wavelength by propagating on orthogonal polarization axis and is easily supported in coherent systems where the polarization tracking can be performed in the digital domain. Furthermore, the forthcoming IEEE 100 Gbit/s Ethernet Standard, 802.3ba, provides greater bandwidth, higher data rates, and supports a mixture of modulation formats. In particular, Pol-MUX (D)QPSK has grown in interest as the high spectral efficiency allows for 100 Gbit/s transmission while still occupying the current 50 GHz/channel allocation of current 10 Gbit/s OOK fiber systems. In this manner, 100 Gbit/s transfer speeds using current fiber links, amplifiers, and filters may be possible. In addition to advanced modulation formats, it is expected that optical

  10. Assessing acute platelet adhesion on opaque metallic and polymeric biomaterials with fiber optic microscopy.

    PubMed

    Schaub, R D; Kameneva, M V; Borovetz, H S; Wagner, W R

    2000-03-15

    The degree of platelet adhesion and subsequent thrombus formation is an important measure of biocompatibility for cardiovascular biomaterials. Traditional methods of quantifying platelet adhesion often are limited by the need for direct optical access, limited spatial resolution, or the lack of temporal resolution. We have developed a new imaging system that utilizes fiber optics and fluorescence microscopy for the quantification of platelet adhesion. This fiber optic remote microscope is capable of imaging individual fluorescently labeled platelets in whole blood on opaque surfaces. Using this method, platelet adhesion was quantified on a series of metallic [low-temperature isotropic carbon (LTIC); titanium alloy (Ti); diamond-like carbon (DLC); oxidized titanium alloy (TiO); and polycrystalline diamond (PCD)] and polymeric [woven Dacron (WD)] collagen-impregnated Dacron (HEM), expanded polytetrafluoroethylene (ePTFE), and denucleated ePTFE (dePTFE)] biomaterials designed for use in cardiovascular applications. These materials were perfused with heparinized whole human blood in an in vitro parallel plate flow chamber. Platelet adhesion after 5 min of perfusion ranged from 3.7 +/- 1.0 (dePTFE) to 16.8 +/- 1.5 (WD) platelets/1000 micrometer. The temporal information revealed by these studies provides a comparative measure of the acute thrombogenicity of these materials as well as some insight into their long-term hemocompatibilities. Also studied here were the effects of wall shear rate and axial position on platelet adhesion. A predicted increase in platelet adhesion with increased wall shear rate and a trend toward a decrease in platelet adhesion with increased axial distance was observed with the fiber optic microscope. Future applications for this imaging technique may include the long-term evaluation of thrombosis in blood-contacting devices in vitro and, in animal models, in vivo.

  11. All-optical optoacoustic microscopy system based on probe beam deflection technique

    NASA Astrophysics Data System (ADS)

    Maswadi, Saher M.; Tsyboulskic, Dmitri; Roth, Caleb C.; Glickman, Randolph D.; Beier, Hope T.; Oraevsky, Alexander A.; Ibey, Bennett L.

    2016-03-01

    It is difficult to achieve sub-micron resolution in backward mode OA microscopy using conventional piezoelectric detectors, because of wavefront distortions caused by components placed in the optical path, between the sample and the objective lens, that are required to separate the acoustic wave from the optical beam. As an alternate approach, an optoacoustic microscope (OAM) was constructed using the probe beam deflection technique (PBDT) to detect laserinduced acoustic signals. The all-optical OAM detects laser-generated pressure waves using a probe beam passing through a coupling medium, such as water, filling the space between the microscope objective lens and sample. The acoustic waves generated in the sample propagate through the coupling medium, causing transient changes in the refractive index that deflect the probe beam. These deflections are measured with a high-speed, balanced photodiode position detector. The deflection amplitude is directly proportional to the magnitude of the acoustic pressure wave, and provides the data required for image reconstruction. The sensitivity of the PBDT detector expressed as noise equivalent pressure was 12 Pa, comparable to that of existing high-performance ultrasound detectors. Because of the unimpeded working distance, a high numerical aperture objective lens, i.e. NA = 1, was employed in the OAM to achieve near diffraction-limited lateral resolution of 0.5 μm at 532nm. The all-optical OAM provides several benefits over current piezoelectric detector-based systems, such as increased lateral and axial resolution, higher sensitivity, robustness, and potentially more compatibility with multimodal instruments.

  12. Computational-optical microscopy for 3D biological imaging beyond the diffraction limit

    NASA Astrophysics Data System (ADS)

    Grover, Ginni

    In recent years, super-resolution imaging has become an important fluorescent microscopy tool. It has enabled imaging of structures smaller than the optical diffraction limit with resolution less than 50 nm. Extension to high-resolution volume imaging has been achieved by integration with various optical techniques. In this thesis, development of a fluorescent microscope to enable high resolution, extended depth, three dimensional (3D) imaging is discussed; which is achieved by integration of computational methods with optical systems. In the first part of the thesis, point spread function (PSF) engineering for volume imaging is discussed. A class of PSFs, referred to as double-helix (DH) PSFs, is generated. The PSFs exhibit two focused spots in the image plane which rotate about the optical axis, encoding depth in rotation of the image. These PSFs extend the depth-of-field up to a factor of ˜5. Precision performance of the DH-PSFs, based on an information theoretical analysis, is compared with other 3D methods with conclusion that the DH-PSFs provide the best precision and the longest depth-of-field. Out of various possible DH-PSFs, a suitable PSF is obtained for super-resolution microscopy. The DH-PSFs are implemented in imaging systems, such as a microscope, with a special phase modulation at the pupil plane. Surface-relief elements which are polarization-insensitive and ˜90% light efficient are developed for phase modulation. The photon-efficient DH-PSF microscopes thus developed are used, along with optimal position estimation algorithms, for tracking and super-resolution imaging in 3D. Imaging at depths-of-field of up to 2.5 microm is achieved without focus scanning. Microtubules were imaged with 3D resolution of (6, 9, 39) nm, which is in close agreement with the theoretical limit. A quantitative study of co-localization of two proteins in volume was conducted in live bacteria. In the last part of the thesis practical aspects of the DH-PSF microscope are

  13. Advanced scanning methods with tracking optical coherence tomography

    PubMed Central

    Ferguson, R. Daniel; Iftimia, Nicusor V.; Ustun, Teoman; Wollstein, Gadi; Ishikawa, Hiroshi; Gabriele, Michelle L.; Dilworth, William D.; Kagemann, Larry; Schuman, Joel S.

    2013-01-01

    An upgraded optical coherence tomography system with integrated retinal tracker (TOCT) was developed. The upgraded system uses improved components to extend the tracking bandwidth, fully integrates the tracking hardware into the optical head of the clinical OCT system, and operates from a single software platform. The system was able to achieve transverse scan registration with sub-pixel accuracy (~10 μm). We demonstrate several advanced scan sequences with the TOCT, including composite scans averaged (co-added) from multiple B-scans taken consecutively and several hours apart, en face images collected by summing the A-scans of circular, line, and raster scans, and three-dimensional (3D) retinal maps of the fovea and optic disc. The new system achieves highly accurate OCT scan registration yielding composite images with significantly improved spatial resolution, increased signal-to-noise ratio, and reduced speckle while maintaining well-defined boundaries and sharp fine structure compared to single scans. Precise re-registration of multiple scans over separate imaging sessions demonstrates TOCT utility for longitudinal studies. En face images and 3D data cubes generated from these data reveal high fidelity image registration with tracking, despite scan durations of more than one minute. PMID:19498823

  14. Crystallization kinetics of poly-(lactic acid) with and without talc: Optical microscopy and calorimetric analysis

    NASA Astrophysics Data System (ADS)

    Refaa, Z.; Boutaous, M.; Rousset, F.; Fulchiron, R.; Zinet, M.; Xin, S.; Bourgin, P.

    2014-05-01

    Poly-(lactic acid) or PLA is a biodegradable polymer synthesized from renewable resources. Recently, the discovery of new polymerization routes has allowed increasing the produced volumes. As a consequence, PLA is becoming of great interest for reducing the dependence on petroleum-based plastics. Because of its interesting mechanical properties, PLA is seen as a potential substitute for some usual polymers. However, its relatively slow crystallization kinetics can be a disadvantage with regard to industrial applications. The crystallization kinetics of PLA can be enhanced by adding nucleating agents, which also influences on crystalline morphology and rheological behavior. In the present work, the isothermal quiescent crystallization kinetics of both neat PLA and PLA/talc composite (5 wt% talc) are investigated. The effects of talc on the overall crystallization kinetics and on the crystalline morphology are analyzed using both optical microscopy measurements and thermal analysis by differential scanning calorimetry.

  15. Portable optical-resolution photoacoustic microscopy with a pulsed laser diode excitation

    NASA Astrophysics Data System (ADS)

    Zeng, Lvming; Liu, Guodong; Yang, Diwu; Ji, Xuanrong

    2013-02-01

    Optical-resolution photoacoustic microscopy (OR-PAM) has been significantly improved in terms of spatial resolution, detection sensitivity, imaging speed, and penetration depth. However, the popular producibility of OR-PAM system is still limited by the size and cost of solid-state laser excitation. Here, we developed a portable laser-diode-based OR-PAM (LD-OR-PAM) system using a pulsed semiconductor laser source, which was operated at 905 ± 15 nm with a pulse energy as low as 4.9 μJ. The measured lateral resolution has been improved to ˜1.5 μm from hundreds of microns. The compact and inexpensive natures of LD-OR-PAM would promote the potential clinical applications such as in dermatology.

  16. Stent-induced coronary artery stenosis characterized by multimodal nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Han-Wei; Simianu, Vlad; Locker, Mattew J.; Cheng, Ji-Xin; Sturek, Michael

    2011-02-01

    We demonstrate for the first time the applicability of multimodal nonlinear optical (NLO) microscopy to the interrogation of stented coronary arteries under different diet and stent deployment conditions. Bare metal stents and Taxus drug-eluting stents (DES) were placed in coronary arteries of Ossabaw pigs of control and atherogenic diet groups. Multimodal NLO imaging was performed to inspect changes in arterial structures and compositions after stenting. Sum frequency generation, one of the multimodalities, was used for the quantitative analysis of collagen content in the peristent and in-stent artery segments of both pig groups. Atherogenic diet increased lipid and collagen in peristent segments. In-stent segments showed decreased collagen expression in neointima compared to media. Deployment of DES in atheromatous arteries inhibited collagen expression in the arterial media.

  17. Fiber optical parametric oscillator for coherent anti-Stokes Raman scattering microscopy.

    PubMed

    Lamb, Erin S; Lefrancois, Simon; Ji, Minbiao; Wadsworth, William J; Xie, X Sunney; Wise, Frank W

    2013-10-15

    We present a synchronously pumped fiber optical parametric oscillator for coherent anti-Stokes Raman scattering microscopy. Pulses from a 1 μm Yb-doped fiber laser are amplified and frequency converted to 779-808 nm through normal dispersion four-wave mixing in a photonic crystal fiber. The idler frequency is resonant in the oscillator cavity, and we find that bandpass filtering the feedback is essential for stable, narrow-bandwidth output. Experimental results agree quite well with numerical simulations of the device. Transform-limited 2 ps pulses with energy up to 4 nJ can be generated at the signal wavelength. The average power is 180 mW, and the relative-intensity noise is much lower than that of a similar parametric amplifier. High-quality coherent Raman images of mouse tissues recorded with this source are presented.

  18. Simultaneous optical coherence and multiphoton microscopy of skin-equivalent tissue models

    NASA Astrophysics Data System (ADS)

    Barton, Jennifer K.; Tang, Shuo; Lim, Ryan; Tromberg, Bruce J.

    2007-07-01

    Three-layer skin-equivalent models (rafts) were created consisting of a collagen/fibroblast layer and an air-exposed keratinocyte layer. Rafts were imaged with a tri-modality microscope including optical coherence (OC), two-photon excited fluorescence (TPEF), and second harmonic generation (SHG) channels. Some rafts were stained with Hoechst 33343 or rhodamine 123, and some were exposed to dimethyl sulfoxide (DMSO). OC microscopy revealed signal in cell cytoplasm and nuclear membranes, and a characteristic texture in the collagen/fibroblast layer. TPEF showed signal in cell cytoplasm and from collagen, and stained specimens revealed cell nuclei or mitochondria. There was little SHG in the keratinocyte layer, but strong signal from collagen bundles. Endogenous signals were severely attenuated in DMSO treated rafts; stained samples revealed shrunken and distorted cell structure. OC, TPEF, and SHG can provide complementary and non-destructive information about raft structure and effect of chemical agents.

  19. Dual tree complex wavelet transform based denoising of optical microscopy images.

    PubMed

    Bal, Ufuk

    2012-12-01

    Photon shot noise is the main noise source of optical microscopy images and can be modeled by a Poisson process. Several discrete wavelet transform based methods have been proposed in the literature for denoising images corrupted by Poisson noise. However, the discrete wavelet transform (DWT) has disadvantages such as shift variance, aliasing, and lack of directional selectivity. To overcome these problems, a dual tree complex wavelet transform is used in our proposed denoising algorithm. Our denoising algorithm is based on the assumption that for the Poisson noise case threshold values for wavelet coefficients can be estimated from the approximation coefficients. Our proposed method was compared with one of the state of the art denoising algorithms. Better results were obtained by using the proposed algorithm in terms of image quality metrics. Furthermore, the contrast enhancement effect of the proposed method on collagen fıber images is examined. Our method allows fast and efficient enhancement of images obtained under low light intensity conditions.

  20. Towards controlling molecular motions in fluorescence microscopy and optical trapping: a spatiotemporal approach

    PubMed Central

    Kumar De, Arijit; Goswami, Debabrata

    2013-01-01

    This account reviews some recent studies pursued in our group on several control experiments with important applications in (one-photon) confocal and two-photon fluorescence laser-scanning microscopy and optical trapping with laser tweezers. We explore the simultaneous control of internal and external (i.e. centre-of-mass motion) degrees of freedom, which require the coupling of various control parameters to result in the spatiotemporal control. Of particular interest to us is the implementation of such control schemes in living systems. A live cell is a system of a large number of different molecules which combine and interact to generate complex structures and functions. These combinations and interactions of molecules need to be choreographed perfectly in time and space to achieve intended intra-cellular functions. Spatiotemporal control promises to be a versatile tool for dynamical control of spatially manipulated bio-molecules. PMID:23814326