Classification of gram-positive and gram-negative foodborne pathogenic bacteria with hyperspectral microscope imaging

USDA-ARS?s Scientific Manuscript database

Optical method with hyperspectral microscope imaging (HMI) has potential for identification of foodborne pathogenic bacteria from microcolonies rapidly with a cell level. A HMI system that provides both spatial and spectral information could be an effective tool for analyzing spectral characteristic...

Microscopic optical model potential based on a Dirac Brueckner Hartree Fock approach and the relevant uncertainty analysis

NASA Astrophysics Data System (ADS)

Xu, Ruirui; Ma, Zhongyu; Muether, Herbert; van Dalen, E. N. E.; Liu, Tinjin; Zhang, Yue; Zhang, Zhi; Tian, Yuan

2017-09-01

A relativistic microscopic optical model potential, named CTOM, for nucleon-nucleus scattering is investigated in the framework of Dirac-Brueckner-Hartree-Fock approach. The microscopic feature of CTOM is guaranteed through rigorously adopting the isospin dependent DBHF calculation within the subtracted T matrix scheme. In order to verify its prediction power, a global study n, p+ A scattering are carried out. The predicted scattering observables coincide with experimental data within a good accuracy over a broad range of targets and a large region of energies only with two free items, namely the free-range factor t in the applied improved local density approximation and minor adjustments of the scalar and vector potentials in the low-density region. In addition, to estimate the uncertainty of the theoretical results, the deterministic simple least square approach is preliminarily employed to derive the covariance of predicted angular distributions, which is also briefly contained in this paper.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhlmann, Andreas V.; Houel, Julien; Warburton, Richard J.

Optically active quantum dots, for instance self-assembled InGaAs quantum dots, are potentially excellent single photon sources. The fidelity of the single photons is much improved using resonant rather than non-resonant excitation. With resonant excitation, the challenge is to distinguish between resonance fluorescence and scattered laser light. We have met this challenge by creating a polarization-based dark-field microscope to measure the resonance fluorescence from a single quantum dot at low temperature. We achieve a suppression of the scattered laser exceeding a factor of 10{sup 7} and background-free detection of resonance fluorescence. The same optical setup operates over the entire quantum dotmore » emission range (920–980 nm) and also in high magnetic fields. The major development is the outstanding long-term stability: once the dark-field point has been established, the microscope operates for days without alignment. The mechanical and optical designs of the microscope are presented, as well as exemplary resonance fluorescence spectroscopy results on individual quantum dots to underline the microscope's excellent performance.« less

Structured illumination 3D microscopy using adaptive lenses and multimode fibers

NASA Astrophysics Data System (ADS)

Czarske, Jürgen; Philipp, Katrin; Koukourakis, Nektarios

2017-06-01

Microscopic techniques with high spatial and temporal resolution are required for in vivo studying biological cells and tissues. Adaptive lenses exhibit strong potential for fast motion-free axial scanning. However, they also lead to a degradation of the achievable resolution because of aberrations. This hurdle can be overcome by digital optical technologies. We present a novel High-and-Low-frequency (HiLo) 3D-microscope using structured illumination and an adaptive lens. Uniform illumination is used to obtain optical sectioning for the high-frequency (Hi) components of the image, and nonuniform illumination is needed to obtain optical sectioning for the low-frequency (Lo) components of the image. Nonuniform illumination is provided by a multimode fiber. It ensures robustness against optical aberrations of the adaptive lens. The depth-of-field of our microscope can be adjusted a-posteriori by computational optics. It enables to create flexible scans, which compensate for irregular axial measurement positions. The adaptive HiLo 3D-microscope provides an axial scanning range of 1 mm with an axial resolution of about 4 microns and sub-micron lateral resolution over the full scanning range. In result, volumetric measurements with high temporal and spatial resolution are provided. Demonstration measurements of zebrafish embryos with reporter gene-driven fluorescence in the thyroid gland are presented.

Multifocal Fluorescence Microscope for Fast Optical Recordings of Neuronal Action Potentials

PubMed Central

Shtrahman, Matthew; Aharoni, Daniel B.; Hardy, Nicholas F.; Buonomano, Dean V.; Arisaka, Katsushi; Otis, Thomas S.

2015-01-01

In recent years, optical sensors for tracking neural activity have been developed and offer great utility. However, developing microscopy techniques that have several kHz bandwidth necessary to reliably capture optically reported action potentials (APs) at multiple locations in parallel remains a significant challenge. To our knowledge, we describe a novel microscope optimized to measure spatially distributed optical signals with submillisecond and near diffraction-limit resolution. Our design uses a spatial light modulator to generate patterned illumination to simultaneously excite multiple user-defined targets. A galvanometer driven mirror in the emission path streaks the fluorescence emanating from each excitation point during the camera exposure, using unused camera pixels to capture time varying fluorescence at rates that are ∼1000 times faster than the camera’s native frame rate. We demonstrate that this approach is capable of recording Ca2+ transients resulting from APs in neurons labeled with the Ca2+ sensor Oregon Green Bapta-1 (OGB-1), and can localize the timing of these events with millisecond resolution. Furthermore, optically reported APs can be detected with the voltage sensitive dye DiO-DPA in multiple locations within a neuron with a signal/noise ratio up to ∼40, resolving delays in arrival time along dendrites. Thus, the microscope provides a powerful tool for photometric measurements of dynamics requiring submillisecond sampling at multiple locations. PMID:25650920

Engineered Potentials and Dynamics of Ultracold Quantum Gases Under the Microscope

DTIC Science & Technology

2014-05-09

CONTRACT OR GRANT NUMBER: DESCRIPTION OF MATERIAL INSTITUTION: PRINCIPAL INVESTIGATOR: Paola Cappellaro TYPE REPORT: Ph.D. Dissertation PERIOD...CONTRACT NUMBER Engineered potentials and dynamics of ulu·acold quantum gases W911NF-11-1-0400 under the microscope Sb. GRANT NUMBER Sc. PROGRAM...Schnorrberger, M. Moreno- Cardoner , S. Fölling, and I. Bloch, “Counting atoms using interaction blockade in an optical superlat- tice,” Phys. Rev. Lett

High resolution tip-tilt positioning system for a next generation MLL-based x-ray microscope

DOE PAGES

Xu, Weihe; Schlossberger, Noah; Xu, Wei; ...

2017-11-15

Multilayer Laue lenses (MLLs) are x-ray focusing optics with the potential to focus hard x-rays down to a single nanometer level. In order to achieve point focus, an MLL microscope needs to have the capability to perform tip-tilt motion of MLL optics and to hold the angular position for an extended period of time. Here, we present a 2D tip-tilt system that can achieve an angular resolution of over 100 microdegree with a working range of 4°, by utilizing a combination of laser interferometer and mini retroreflector. The linear dimensions of the developed system are about 30 mm in allmore » directions, and the thermal dissipation of the system during operation is negligible. Compact design and high angular resolution make the developed system suitable for MLL optics alignment in the next generation of MLL-based x-ray microscopes.« less

High resolution tip-tilt positioning system for a next generation MLL-based x-ray microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Weihe; Schlossberger, Noah; Xu, Wei

Multilayer Laue lenses (MLLs) are x-ray focusing optics with the potential to focus hard x-rays down to a single nanometer level. In order to achieve point focus, an MLL microscope needs to have the capability to perform tip-tilt motion of MLL optics and to hold the angular position for an extended period of time. Here, we present a 2D tip-tilt system that can achieve an angular resolution of over 100 microdegree with a working range of 4°, by utilizing a combination of laser interferometer and mini retroreflector. The linear dimensions of the developed system are about 30 mm in allmore » directions, and the thermal dissipation of the system during operation is negligible. Compact design and high angular resolution make the developed system suitable for MLL optics alignment in the next generation of MLL-based x-ray microscopes.« less

The Scanning Optical Microscope: An Overview

NASA Astrophysics Data System (ADS)

Kino, G. S.; Corte, T. R.; Xiao, G. Q.

1988-07-01

In the last few years there has been a resurgence in research on optical microscopes. One reason stems from the invention of the acoustic microscope by Quate and Lemons,1 and the realization that some of the same principles could be applied to the optical microscope. The acoustic microscope has better transverse definition for the same wavelength than the standard optical microscope and at the same time has far better range definition. Consequently, Kompfner, who was involved with the work on the early acoustic microscope, decided to try out similar scanning microscope principles with optics, and started a group with Wilson and Sheppard to carry out such research at Oxford.2 Sometime earlier, Petran et a13 had invented the tandem scanning microscope which used many of the same principles. Now, in our laboratory at Stanford, these ideas on the tandem scanning microscope and the scanning optical microscope are converging. Another aspect of this work, which stems from the earlier experience with the acoustic microscope, involves measurement of both phase and amplitude of the optical beam. It is also possible to use scanned optical microscopy for other purposes. For instance, an optical beam can be used to excite electrons and holes in semiconductors, and the generated current can be measured. By scanning the optical beam over the semiconductor, an image can be obtained of the regions where there is strong or weak electron hole generation. This type of microscope is called OBIC (Optical Beam Induced Current). A second application involves fluorescent imaging of biological materials. Here we have the excellent range definition of a scanning optical microscope which eliminates unwanted glare from regions of the material where the beam is unfocused.3 A third application is focused on the heating effect of the light beam. With such a system, images can be obtained which are associated with changes in the thermal properties of a material, changes in recombination rates in semiconductors, and differences in material properties associated with either acoustic or thermal effects.4,5 Thus, the range of scanning optical microscopy applications is very large. In the main, the most important applications have been to semiconductors and to biology.

L-Phenylalanine functionalized silver nanoparticles: Photocatalytic and nonlinear optical applications

NASA Astrophysics Data System (ADS)

Nidya, M.; Umadevi, M.; Sankar, Pranitha; Philip, Reji; Rajkumar, Beulah J. M.

2015-04-01

An extensive study on the behavior of L-Phenylalanine capped silver nanoparticles (Phe-Ag NPs) in the aqueous phase and in a sol-gel thin film showed different UV/Vis, Transmission Electron Microscope (TEM), Dynamic Light Scattering and Zeta potential profiles. Scanning Electron Microscope (SEM) images of the samples in the sol gel film showed Ag embedded in the SiO2 matrix. Surface Enhanced Raman Spectra (SERS) confirmed that both in the aqueous media and in the sol gel film, the attachment of Phe to the Ag NP surface was through the benzene ring, with the sol-gel film showing a better enhancement. Photocatalytic degradation of crystal violet was measured spectrophotometrically using Phe-Ag NPs as a nanocatalyst under visible light illumination. Intensity-dependent nonlinear optical absorption of Phe-Ag measured using the open aperture Z-scan technique revealed that the material is an efficient optical limiter with potential applications.

Microscopic few-body and Gaussian-shaped density distributions for the analysis of the 6He exotic nucleus with different target nuclei

NASA Astrophysics Data System (ADS)

Aygun, M.; Kucuk, Y.; Boztosun, I.; Ibraheem, Awad A.

2010-12-01

The elastic scattering angular distributions of 6He projectile on different medium and heavy mass target nuclei including 12C, 27Al, 58Ni, 64Zn, 65Cu, 197Au, 208Pb and 209Bi have been examined by using the few-body and Gaussian-shaped density distributions at various energies. The microscopic real parts of the complex nuclear optical potential have been obtained by using the double-folding model for each of the density distributions and the phenomenological imaginary potentials have been taken as the Woods-Saxon type. Comparative results of the few-body and Gaussian-shaped density distributions together with the experimental data are presented within the framework of the optical model.

Optical Coherence Tomography–Enhanced Microlaryngoscopy: Preliminary Report of a Noncontact Optical Coherence Tomography System Integrated With a Surgical Microscope

PubMed Central

Vokes, David E.; Jackson, Ryan; Guo, Shuguang; Perez, Jorge A.; Su, Jianping; Ridgway, James M.; Armstrong, William B.; Chen, Zhongping; Wong, Brian J. F.

2014-01-01

Objectives Optical coherence tomography (OCT) is a new imaging modality that uses near-infrared light to produce cross-sectional images of tissue with a resolution approaching that of light microscopy. We have previously reported use of OCT imaging of the vocal folds (VFs) during direct laryngoscopy with a probe held in contact or near-contact with the VFs. This aim of this study was to develop and evaluate a novel OCT system integrated with a surgical microscope to allow hands-free OCT imaging of the VFs, which could be performed simultaneously with microscopic visualization. Methods We performed a prospective evaluation of a new method of acquiring OCT images of the VFs. Results An OCT system was successfully integrated with a surgical microscope to permit noncontact OCT imaging of the VFs of 10 patients. With this novel device we were able to identify VF epithelium and lamina propria; however, the resolution was reduced compared to that achieved with the standard contact or near-contact OCT. Conclusions Optical coherence tomography is able to produce high-resolution images of vocal fold mucosa to a maximum depth of 1.6 mm. It may be used in the diagnosis of VF lesions, particularly early squamous cell carcinoma, in which OCT can show disruption of the basement membrane. Mounting the OCT device directly onto the operating microscope allows hands-free noncontact OCT imaging and simultaneous conventional microscopic visualization of the VFs. However, the lateral resolution of the OCT microscope system is 50 µm, in contrast to the conventional handheld probe system (10 µm). Although such images at this resolution are still useful clinically, improved resolution would enhance the system’s performance, potentially enabling real-time OCT-guided microsurgery of the larynx. PMID:18700431

Differential polarization nonlinear optical microscopy with adaptive optics controlled multiplexed beams.

PubMed

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

2013-09-09

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.

Study of 11Li+p elastic scattering using BHF formalism with three body force

NASA Astrophysics Data System (ADS)

Sharma, Manjari; Haider, W.

2018-04-01

In the present work we have analyzed the elastic scattering data of 11Li + p at 62, 68.4 and 75 MeV/nucleon, using the microscopic optical potential calculated within the framework of Brueckner-Hartree-Fock formalism (BHF). The calculation uses Argonne v18 and Urbana v14 inter-nucleon potentials and the Urbana IX (UVIX) model of three body force. The required nucleon-density distributions for 11Li are obtained using the semi-phenomenological model for nuclear density distributions. The optical potential has been obtained by folding the g-matrices as calculated in BHF (with and without three body forces) over the nucleon density distributions. We have used the exact method for calculating both the direct and the exchange parts of the spin-orbit potential. Our results reveal that the spin-orbit potential significantly contributes to 11Li+p elastic scattering at all three incident energies. Further, the calculated spin-orbit potential in BHF is much smaller and more diffused as compared with the phenomenological spin-orbit potential. The analysis reveals that the calculated microscopic optical potentials, with and without three body force using BHF approach with phenomenological form of density distribution, provides satisfactory agreement with the elastic scattering data for 11Li+p.

Optical properties of graphene superlattices.

PubMed

Le, H Anh; Ho, S Ta; Nguyen, D Chien; Do, V Nam

2014-10-08

In this work, the optical responses of graphene superlattices, i.e. graphene subjected to a periodic scalar potential, are theoretically reported. The optical properties were studied by investigating the optical conductivity, which was calculated using the Kubo formalism. It was found that the optical conductivity becomes dependent on the photon polarization and is suppressed in the photon energy range of (0, Ub), where Ub is the potential barrier height. In the higher photon energy range, i.e. Ω > Ub, the optical conductivity is, however, almost identical to that of pristine graphene. Such behaviors of the optical conductivity are explained microscopically through the analysis of the elements of optical matrices and effectively through a simple model, which is based on the Pauli blocking mechanism.

Optimal model-based sensorless adaptive optics for epifluorescence microscopy.

PubMed

Pozzi, Paolo; Soloviev, Oleg; Wilding, Dean; Vdovin, Gleb; Verhaegen, Michel

2018-01-01

We report on a universal sample-independent sensorless adaptive optics method, based on modal optimization of the second moment of the fluorescence emission from a point-like excitation. Our method employs a sample-independent precalibration, performed only once for the particular system, to establish the direct relation between the image quality and the aberration. The method is potentially applicable to any form of microscopy with epifluorescence detection, including the practically important case of incoherent fluorescence emission from a three dimensional object, through minor hardware modifications. We have applied the technique successfully to a widefield epifluorescence microscope and to a multiaperture confocal microscope.

Spin microscope based on optically detected magnetic resonance

DOEpatents

Berman, Gennady P [Los Alamos, NM; Chernobrod, Boris M [Los Alamos, NM

2010-06-29

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Spin microscope based on optically detected magnetic resonance

DOEpatents

Berman, Gennady P.; Chernobrod, Boris M.

2009-11-10

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of impaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Spin microscope based on optically detected magnetic resonance

DOEpatents

Berman, Gennady P.; Chernobrod, Boris M.

2007-12-11

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Spin microscope based on optically detected magnetic resonance

DOEpatents

Berman, Gennady P [Los Alamos, NM; Chernobrod, Boris M [Los Alamos, NM

2010-07-13

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Spin microscope based on optically detected magnetic resonance

DOEpatents

Berman, Gennady P [Los Alamos, NM; Chernobrod, Boris M [Los Alamos, NM

2009-10-27

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Microscopic Studies of Quantum Phase Transitions in Optical Lattices

NASA Astrophysics Data System (ADS)

Bakr, Waseem S.

2011-12-01

In this thesis, I report on experiments that microscopically probe quantum phase transitions of ultracold atoms in optical lattices. We have developed a "quantum gas microscope" that allowed, for the first time, optical imaging and manipulation of single atoms in a quantum-degenerate gas on individual sites of an optical lattice. This system acts as a quantum simulator of strongly correlated materials, which are currently the subject of intense research because of the technological potential of high--T c superconductors and spintronic materials. We have used our microscope to study the superfluid to Mott insulator transition in bosons and a magnetic quantum phase transition in a spin system. In our microscopic study of the superfluid-insulator transition, we have characterized the on-site number statistics in a space- and time-resolved manner. We observed Mott insulators with fidelities as high as 99%, corresponding to entropies of 0.06kB per particle. We also measured local quantum dynamics and directly imaged the shell structure of the Mott insulator. I report on the first quantum magnetism experiments in optical lattices. We have realized a quantum Ising chain in a magnetic field, and observed a quantum phase transition between a paramagnet and antiferromagnet. We achieved strong spin interactions by encoding spins in excitations of a Mott insulator in a tilted lattice. We detected the transition by measuring the total magnetization of the system across the transition using in-situ measurements as well as the Neel ordering in the antiferromagnetic state using noise-correlation techniques. We characterized the dynamics of domain formation in the system. The spin mapping introduced opens up a new path to realizing more exotic states in optical lattices including spin liquids and quantum valence bond solids. As our system sizes become larger, simulating their physics on classical computers will require exponentially larger resources because of entanglement build-up near a quantum phase transition. We have demonstrated a quantum simulator in which all degrees of freedom can be read out microscopically, allowing the simulation of quantum many-body systems with manageable resources. More generally, the ability to image and manipulate individual atoms in optical lattices opens an avenue towards scalable quantum computation.

Multimodal Nonlinear Optical Microscopy

PubMed Central

Yue, Shuhua; Slipchenko, Mikhail N.; Cheng, Ji-Xin

2013-01-01

Because each nonlinear optical (NLO) imaging modality is sensitive to specific molecules or structures, multimodal NLO imaging capitalizes the potential of NLO microscopy for studies of complex biological tissues. The coupling of multiphoton fluorescence, second harmonic generation, and coherent anti-Stokes Raman scattering (CARS) has allowed investigation of a broad range of biological questions concerning lipid metabolism, cancer development, cardiovascular disease, and skin biology. Moreover, recent research shows the great potential of using CARS microscope as a platform to develop more advanced NLO modalities such as electronic-resonance-enhanced four-wave mixing, stimulated Raman scattering, and pump-probe microscopy. This article reviews the various approaches developed for realization of multimodal NLO imaging as well as developments of new NLO modalities on a CARS microscope. Applications to various aspects of biological and biomedical research are discussed. PMID:24353747

Sub-nanosecond time-resolved near-field scanning magneto-optical microscope.

PubMed

Rudge, J; Xu, H; Kolthammer, J; Hong, Y K; Choi, B C

2015-02-01

We report on the development of a new magnetic microscope, time-resolved near-field scanning magneto-optical microscope, which combines a near-field scanning optical microscope and magneto-optical contrast. By taking advantage of the high temporal resolution of time-resolved Kerr microscope and the sub-wavelength spatial resolution of a near-field microscope, we achieved a temporal resolution of ∼50 ps and a spatial resolution of <100 nm. In order to demonstrate the spatiotemporal magnetic imaging capability of this microscope, the magnetic field pulse induced gyrotropic vortex dynamics occurring in 1 μm diameter, 20 nm thick CoFeB circular disks has been investigated. The microscope provides sub-wavelength resolution magnetic images of the gyrotropic motion of the vortex core at a resonance frequency of ∼240 MHz.

The Scanning Optical Microscope.

ERIC Educational Resources Information Center

Sheppard, C. J. R.

1978-01-01

Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

Microscopic optical potentials derived from ab initio translationally invariant nonlocal one-body densities

NASA Astrophysics Data System (ADS)

Gennari, Michael; Vorabbi, Matteo; Calci, Angelo; Navrátil, Petr

2018-03-01

Background: The nuclear optical potential is a successful tool for the study of nucleon-nucleus elastic scattering and its use has been further extended to inelastic scattering and other nuclear reactions. The nuclear density of the target nucleus is a fundamental ingredient in the construction of the optical potential and thus plays an important role in the description of the scattering process. Purpose: In this paper we derive a microscopic optical potential for intermediate energies using ab initio translationally invariant nonlocal one-body nuclear densities computed within the no-core shell model (NCSM) approach utilizing two- and three-nucleon chiral interactions as the only input. Methods: The optical potential is derived at first order within the spectator expansion of the nonrelativistic multiple scattering theory by adopting the impulse approximation. Nonlocal nuclear densities are derived from the NCSM one-body densities calculated in the second quantization. The translational invariance is generated by exactly removing the spurious center-of-mass (COM) component from the NCSM eigenstates. Results: The ground-state local and nonlocal densities of He 4 ,6 ,8 , 12C, and 16O are calculated and applied to optical potential construction. The differential cross sections and the analyzing powers for the elastic proton scattering off these nuclei are then calculated for different values of the incident proton energy. The impact of nonlocality and the COM removal is discussed. Conclusions: The use of nonlocal densities has a substantial impact on the differential cross sections and improves agreement with experiment in comparison to results generated with the local densities especially for light nuclei. For the halo nuclei 6He and 8He, the results for the differential cross section are in a reasonable agreement with the data although a more sophisticated model for the optical potential is required to properly describe the analyzing powers.

Preparing and probing many-body correlated systems in a Quantum Gas Microscope by engineering arbitrary landscape potentials

NASA Astrophysics Data System (ADS)

Rispoli, Matthew; Lukin, Alexander; Ma, Ruichao; Preiss, Philipp; Tai, M. Eric; Islam, Rajibul; Greiner, Markus

2015-05-01

Ultracold atoms in optical lattices provide a versatile tool box for observing the emergence of strongly correlated physics in quantum systems. Dynamic control of optical potentials on the single-site level allows us to prepare and probe many-body quantum states through local Hamiltonian engineering. We achieve these high precision levels of optical control through spatial light modulation with a DMD (digital micro-mirror device). This allows for both arbitrary beam shaping and aberration compensation in our imaging system to produce high fidelity optical potentials. We use these techniques to control state initialization, Hamiltonian dynamics, and measurement in experiments investigating low-dimensional many-body physics - from one-dimensional correlated quantum walks to characterizing entanglement.

Microscope collision protection apparatus

DOEpatents

DeNure, Charles R.

2001-10-23

A microscope collision protection apparatus for a remote control microscope which protects the optical and associated components from damage in the event of an uncontrolled collision with a specimen, regardless of the specimen size or shape. In a preferred embodiment, the apparatus includes a counterbalanced slide for mounting the microscope's optical components. This slide replaces the rigid mounts on conventional upright microscopes with a precision ball bearing slide. As the specimen contacts an optical component, the contacting force will move the slide and the optical components mounted thereon. This movement will protect the optical and associated components from damage as the movement causes a limit switch to be actuated, thereby stopping all motors responsible for the collision.

Real-time Optical Coherence Tomography Incorporated in the Operating Microscope during Cataract Surgery.

PubMed

Almutlak, Mohammed A; Aloniazan, Turki; May, William

2017-01-01

A 55-year-old male presented with reduced vision due to senile cataract. The patient consented to undergo real-time intraoperative anterior segment-optical coherence tomography (AS-OCT) during phacoemulsification with intraocular lens (IOL) implantation. Images were captured at various points during the surgery. The use of AS-OCT incorporated into the surgical microscope was evaluated as an adjunct to cataract surgery. We were able to successfully evaluate, in real-time, wound architecture, the attachment of Descemet's membrane, the posterior capsule, and IOL position. Real-time AS-OCT can be used to proactively address potential complications and verify IOL placement intraoperatively.

Optical second harmonic images of 90 deg domain structure in BaTiO3 and periodically inverted antiparallel domains in LiTaO3

NASA Astrophysics Data System (ADS)

Uesu, Y.; Kurimura, S.; Yamamoto, Y.

1995-04-01

Applied is a microscope to observations of 90 deg ferroelectric domain structure in BaTiO3 and inverted periodically are ferroelectric domains in LiTaO3. It is founded that the second harmonic generation microscope gives information which cannot be obtained by ordinary optical microscopes. The developed nonlinear optical microscope builds two dimensional second harmonic image of a specimen with inhomogenous distribution of d(sub ijk) and applied the microscope to observations of inhomogeneity in some nonlinear-optical organic microcrystals.

Compact variable-temperature scanning force microscope.

PubMed

Chuang, Tien-Ming; de Lozanne, Alex

2007-05-01

A compact design for a cryogenic variable-temperature scanning force microscope using a fiber-optic interferometer to measure cantilever deflection is presented. The tip-sample coarse approach and the lateral tip positioning are performed by piezoelectric positioners in situ. The microscope has been operated at temperatures between 6 and 300 K. It is designed to fit into an 8 T superconducting magnet with the field applied in the out-of-plane direction. The results of scanning in various modes are demonstrated, showing contrast based on magnetic field gradients or surface potentials.

Waveguide bends from nanometric silica wires

NASA Astrophysics Data System (ADS)

Tong, Limin; Lou, Jingyi; Mazur, Eric

2005-02-01

We propose to use bent silica wires with nanometric diameters to guide light as optical waveguide bend. We bend silica wires with scanning tunneling microscope probes under an optical microscope, and wire bends with bending radius smaller than 5 μm are obtained. Light from a He-Ne laser is launched into and guided through the wire bends, measured bending loss of a single bend is on the order of 1 dB. Brief introductions to the optical wave guiding and elastic bending properties of silica wires are also provided. Comparing with waveguide bends based on photonic bandgap structures, the waveguide bends from silica nanometric wires show advantages of simple structure, small overall size, easy fabrication and wide useful spectral range, which make them potentially useful in the miniaturization of photonic devices.

The microscopic (optical and SEM) examination of dental calculus deposits (DCD). Potential interest in forensic anthropology of a bio-archaeological method.

PubMed

Charlier, Philippe; Huynh-Charlier, Isabelle; Munoz, Olivia; Billard, Michel; Brun, Luc; de la Grandmaison, Geoffroy Lorin

2010-07-01

This article describes the potential interest in forensic anthropology of the microscopic analysis of dental calculus deposits (DCD), a calcified residue frequently found on the surface of teeth. Its sampling and analysis seem straightforward and relatively reproducible. Samples came from archaeological material (KHB-1 Ra's al-Khabbah and RH-5 Ra's al-Hamra, two Prehistoric graveyards located in the Sultanate of Oman, dated between the 5th and 4th millennium B.C.; Montenzio Vecchia, an Etruscan-Celtic necropolis from the north of Italy, dated between the 5th and 3rd century B.C.; body rests of Agnès Sorel, French royal mistress died in 1450 A.D.; skeleton of Pierre Hazard, French royal notary from the 15th century A.D.). Samples were studies by direct optical microscope (OM) or scanning electron microscopy (SEM). Many cytological, histological and elemental analyses were possible, producing precious data for the identification of these remains, the reconstitution of their alimentation and occupational habits, and propositions for manner of death. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Adaptive optics plug-and-play setup for high-resolution microscopes with multi-actuator adaptive lens

NASA Astrophysics Data System (ADS)

Quintavalla, M.; Pozzi, P.; Verhaegen, Michelle; Bijlsma, Hielke; Verstraete, Hans; Bonora, S.

2018-02-01

Adaptive Optics (AO) has revealed as a very promising technique for high-resolution microscopy, where the presence of optical aberrations can easily compromise the image quality. Typical AO systems however, are almost impossible to implement on commercial microscopes. We propose a simple approach by using a Multi-actuator Adaptive Lens (MAL) that can be inserted right after the objective and works in conjunction with an image optimization software allowing for a wavefront sensorless correction. We presented the results obtained on several commercial microscopes among which a confocal microscope, a fluorescence microscope, a light sheet microscope and a multiphoton microscope.

Development of an ultrasound microscope combined with optical microscope for multiparametric characterization of a single cell.

PubMed

Arakawa, Mototaka; Shikama, Joe; Yoshida, Koki; Nagaoka, Ryo; Kobayashi, Kazuto; Saijo, Yoshifumi

2015-09-01

Biomechanics of the cell has been gathering much attention because it affects the pathological status in atherosclerosis and cancer. In the present study, an ultrasound microscope system combined with optical microscope for characterization of a single cell with multiple ultrasound parameters was developed. The central frequency of the transducer was 375 MHz and the scan area was 80 × 80 μm with up to 200 × 200 sampling points. An inverted optical microscope was incorporated in the design of the system, allowing for simultaneous optical observations of cultured cells. Two-dimensional mapping of multiple ultrasound parameters, such as sound speed, attenuation, and acoustic impedance, as well as the thickness, density, and bulk modulus of specimen/cell under investigation, etc., was realized by the system. Sound speed and thickness of a 3T3-L1 fibroblast cell were successfully obtained by the system. The ultrasound microscope system combined with optical microscope further enhances our understanding of cellular biomechanics.

Micro-optics technology and sensor systems applications

NASA Technical Reports Server (NTRS)

Gal, George; Herman, B.; Anderson, W.; Whitney, R.; Morrow, H.

1993-01-01

The current generation of electro-optical sensors utilizing refractive and reflective optical elements require sophisticated, complex, and expensive designs. Advanced-technology-based electro-optical sensors of minimum size and weight require miniaturization of optical, electrical, and mechanical devices with an increasing trend toward integration of various components. Micro-optics technology has the potential in a number of areas to simplify optical design with improved performance. This includes internally cooled apertures, hybrid optical design, microlenses, dispersive multicolor microlenses, active dither, electronically controlled optical beam steer, and microscopic integration of micro-optics, detectors, and signal processing layers. This paper describes our approach to the development of micro-optics technology with our main emphasis for sensors applications.

Limits of agreement between the optical pachymeter and a noncontact specular microscope.

PubMed

Ogbuehi, Kelechi C; Almubrad, Turki M

2005-07-01

To determine the limits of agreement between central corneal thickness (CCT) measurements made with the slit lamp-attached optical pachymeter and the SP2000P noncontact specular microscope. Triplicate readings for CCT were obtained for each of 130 (right) eyes of 130 patients, using the slit lamp-attached optical pachymeter and then the SP2000P noncontact specular microscope. The average CCT measured by each method was compared. Subsequently, the mean difference between both sets of measurements was assessed, and the 95% confidence interval (limits of agreement) between both techniques was determined. The mean +/- SD CCT measured by the optical pachymeter was 543 +/- 34 microm and 532 +/- 34 microm for the specular microscope. We found a statistically significant (P < 0.001) mean bias of 10 mum between CCT values measured with both types of equipment, with the optical pachymeter returning the higher values. The coefficient of variation was 6.3% for the optical pachymeter and 6.4% for the specular microscope. The right eye CCT measurements made by the optical pachymeter are, on average, 10 mum thicker than those made with the SP2000P specular microscope, which suggests that both pieces of equipment cannot be used interchangeably to monitor CCT changes in patients. Excluding left eye measurements, the reliability of the optical pachymeter is identical to that of the noncontact specular microscope.

Closed loop adaptive optics for microscopy without a wavefront sensor.

PubMed

Kner, Peter; Winoto, Lukman; Agard, David A; Sedat, John W

2010-02-24

A three-dimensional wide-field image of a small fluorescent bead contains more than enough information to accurately calculate the wavefront in the microscope objective back pupil plane using the phase retrieval technique. The phase-retrieved wavefront can then be used to set a deformable mirror to correct the point-spread function (PSF) of the microscope without the use of a wavefront sensor. This technique will be useful for aligning the deformable mirror in a widefield microscope with adaptive optics and could potentially be used to correct aberrations in samples where small fluorescent beads or other point sources are used as reference beacons. Another advantage is the high resolution of the retrieved wavefont as compared with current Shack-Hartmann wavefront sensors. Here we demonstrate effective correction of the PSF in 3 iterations. Starting from a severely aberrated system, we achieve a Strehl ratio of 0.78 and a greater than 10-fold increase in maximum intensity.

Imaging Schwarzschild multilayer X-ray microscope

NASA Technical Reports Server (NTRS)

Hoover, Richard B.; Baker, Phillip C.; Shealy, David L.; Core, David B.; Walker, Arthur B. C., Jr.; Barbee, Troy W., Jr.; Kerstetter, Ted

1993-01-01

We have designed, analyzed, fabricated, and tested Schwarzschild multilayer X-ray microscopes. These instruments use flow-polished Zerodur mirror substrates which have been coated with multilayers optimized for maximum reflectivity at normal incidence at 135 A. They are being developed as prototypes for the Water Window Imaging X-Ray Microscope. Ultrasmooth mirror sets of hemlite grade sapphire have been fabricated and they are now being coated with multilayers to reflect soft X-rays at 38 A, within the biologically important 'water window'. In this paper, we discuss the fabrication of the microscope optics and structural components as well as the mounting of the optics and assembly of the microscopes. We also describe the optical alignment, interferometric and visible light testing of the microscopes, present interferometrically measured performance data, and provide the first results of optical imaging tests.

Two-Photon Imaging with Diffractive Optical Elements

PubMed Central

Watson, Brendon O.; Nikolenko, Volodymyr; Yuste, Rafael

2009-01-01

Two-photon imaging has become a useful tool for optical monitoring of neural circuits, but it requires high laser power and serial scanning of each pixel in a sample. This results in slow imaging rates, limiting the measurements of fast signals such as neuronal activity. To improve the speed and signal-to-noise ratio of two-photon imaging, we introduce a simple modification of a two-photon microscope, using a diffractive optical element (DOE) which splits the laser beam into several beamlets that can simultaneously scan the sample. We demonstrate the advantages of DOE scanning by enhancing the speed and sensitivity of two-photon calcium imaging of action potentials in neurons from neocortical brain slices. DOE scanning can easily improve the detection of time-varying signals in two-photon and other non-linear microscopic techniques. PMID:19636390

Science 101: How Does an Electron Microscope Work?

ERIC Educational Resources Information Center

Robertson, Bill

2013-01-01

Contrary to popular opinion, electron microscopes are not used to look at electrons. They are used to look for structure in things that are too small to observe with an optical microscope, or to obtain images that are magnified much more than is obtainable with an optical microscope. To understand how electron microscopes work, it will help to go…

Adaptive optical microscope for brain imaging in vivo

NASA Astrophysics Data System (ADS)

Wang, Kai

2017-04-01

The optical heterogeneity of biological tissue imposes a major limitation to acquire detailed structural and functional information deep in the biological specimens using conventional microscopes. To restore optimal imaging performance, we developed an adaptive optical microscope based on direct wavefront sensing technique. This microscope can reliably measure and correct biological samples induced aberration. We demonstrated its performance and application in structural and functional brain imaging in various animal models, including fruit fly, zebrafish and mouse.

Miniature in vivo MEMS-based line-scanned dual-axis confocal microscope for point-of-care pathology

PubMed Central

Yin, C.; Glaser, A.K.; Leigh, S. Y.; Chen, Y.; Wei, L.; Pillai, P. C. S.; Rosenberg, M. C.; Abeytunge, S.; Peterson, G.; Glazowski, C.; Sanai, N.; Mandella, M. J.; Rajadhyaksha, M.; Liu, J. T. C.

2016-01-01

There is a need for miniature optical-sectioning microscopes to enable in vivo interrogation of tissues as a real-time and noninvasive alternative to gold-standard histopathology. Such devices could have a transformative impact for the early detection of cancer as well as for guiding tumor-resection procedures. Miniature confocal microscopes have been developed by various researchers and corporations to enable optical sectioning of highly scattering tissues, all of which have necessitated various trade-offs in size, speed, depth selectivity, field of view, resolution, image contrast, and sensitivity. In this study, a miniature line-scanned (LS) dual-axis confocal (DAC) microscope, with a 12-mm diameter distal tip, has been developed for clinical point-of-care pathology. The dual-axis architecture has demonstrated an advantage over the conventional single-axis confocal configuration for reducing background noise from out-of-focus and multiply scattered light. The use of line scanning enables fast frame rates (16 frames/sec is demonstrated here, but faster rates are possible), which mitigates motion artifacts of a hand-held device during clinical use. We have developed a method to actively align the illumination and collection beams in a DAC microscope through the use of a pair of rotatable alignment mirrors. Incorporation of a custom objective lens, with a small form factor for in vivo clinical use, enables our device to achieve an optical-sectioning thickness and lateral resolution of 2.0 and 1.1 microns respectively. Validation measurements with reflective targets, as well as in vivo and ex vivo images of tissues, demonstrate the clinical potential of this high-speed optical-sectioning microscopy device. PMID:26977337

Optical transmembrane potential measurements during defibrillation-strength shocks in perfused rabbit hearts.

PubMed

Zhou, X; Ideker, R E; Blitchington, T F; Smith, W M; Knisley, S B

1995-09-01

To study the optical transmembrane potential change (delta F) induced during shocks, optical recordings were obtained in 15 isolated perfused rabbit hearts treated with the potentiometric dye di-4-ANEPPS and diacetyl monoxime. Shock electrodes were sutured on the right and left ventricles. A laser beam 30 microns in diameter was used to optically excite di-4-ANEPPS. Fluorescence from a region 150 microns in diameter was recorded during a shock. In the macroscopic study (six animals), there were nine recording spots that were 3 mm apart between the two shock electrodes. In the microscopic study, there were three recording regions that were 3 mm away from either shock electrode and midway between them, with nine recording spots that were 30 microns (three animals), 100 microns (three animals), and 300 microns (three animals) apart in each region. After 20 S1 stimuli, a 10-ms truncated exponential S2 shock of defibrillation-threshold strength was given during the plateau of the last S1 action potential. In the microscopic study, shocks were also given during diastole, with delta F recordings at the three recording regions. Shocks of both polarities were tested. delta F during the shock was expressed as a percentage of the fluorescence change during the S1 upstroke action potential amplitude (the S1 Fapa), ie, delta F/Fapa%. In the macroscopic study, the magnitudes of delta F/Fapa% from recording spots 1 to 9, numbered from the left to the right ventricular electrodes, were 77 +/- 41%, 46 +/- 32%, 32 +/- 27%, 28 +/- 20%, 37 +/- 25%, 24 +/- 20%, 33 +/- 22%, 37 +/- 25%, and 59 +/- 29%, respectively (P < .05 among the nine spots). Depolarization or hyperpolarization could occur near either shock electrode with both shock polarities, but the magnitude of hyperpolarization was 1.8 +/- 0.9 times that of depolarization at the same recording spot when the shock polarity was reversed (P < .01). In the microscopic study, the change in delta F/Fapa% varied significantly over the microscopic regions examined. The maximum values of delta F/Fapa% for hyperpolarizing shocks during diastole reached only 7 +/- 10% of those for shocks during the plateau (P < .01). During diastole, the time until a new action potential occurred after the beginning of the shock was shorter when the membrane was depolarized (1.1 +/- 0.5 ms) than when it was hyperpolarized (12.8 +/- 9.1 ms, P < .01). Conclusions are as follows: (1) A shock can induce either hyperpolarization or depolarization. (2) Hyperpolarization or depolarization during a shock can occur near either the anodal or cathodal shock electrode. (3) Variation of delta F/Fapa% exists within a microscopic region.(ABSTRACT TRUNCATED AT 400 WORDS)

New design of a cryostat-mounted scanning near-field optical microscope for single molecule spectroscopy

NASA Astrophysics Data System (ADS)

Durand, Yannig; Woehl, Jörg C.; Viellerobe, Bertrand; Göhde, Wolfgang; Orrit, Michel

1999-02-01

Due to the weakness of the fluorescence signal from a single fluorophore, a scanning near-field optical microscope for single molecule spectroscopy requires a very efficient setup for the collection and detection of emitted photons. We have developed a home-built microscope for operation in a l-He cryostat which uses a solid parabolic mirror in order to optimize the fluorescence collection efficiency. This microscope works with Al-coated, tapered optical fibers in illumination mode. The tip-sample separation is probed by an optical shear-force detection. First results demonstrate the capability of the microscope to image single molecules and achieve a topographical resolution of a few nanometers vertically and better than 50 nm laterally.

A stereo-compound hybrid microscope for combined intracellular and optical recording of invertebrate neural network activity.

PubMed

Frost, William N; Wang, Jean; Brandon, Christopher J

2007-05-15

Optical recording studies of invertebrate neural networks with voltage-sensitive dyes seldom employ conventional intracellular electrodes. This may in part be due to the traditional reliance on compound microscopes for such work. While such microscopes have high light-gathering power, they do not provide depth of field, making working with sharp electrodes difficult. Here we describe a hybrid microscope design, with switchable compound and stereo objectives, that eases the use of conventional intracellular electrodes in optical recording experiments. We use it, in combination with a voltage-sensitive dye and photodiode array, to identify neurons participating in the swim motor program of the marine mollusk Tritonia. This microscope design should be applicable to optical recording studies in many preparations.

X-ray laser microscope apparatus

DOEpatents

Suckewer, Szymon; DiCicco, Darrell S.; Hirschberg, Joseph G.; Meixler, Lewis D.; Sathre, Robert; Skinner, Charles H.

1990-01-01

A microscope consisting of an x-ray contact microscope and an optical microscope. The optical, phase contrast, microscope is used to align a target with respect to a source of soft x-rays. The source of soft x-rays preferably comprises an x-ray laser but could comprise a synchrotron or other pulse source of x-rays. Transparent resist material is used to support the target. The optical microscope is located on the opposite side of the transparent resist material from the target and is employed to align the target with respect to the anticipated soft x-ray laser beam. After alignment with the use of the optical microscope, the target is exposed to the soft x-ray laser beam. The x-ray sensitive transparent resist material whose chemical bonds are altered by the x-ray beam passing through the target mater GOVERNMENT LICENSE RIGHTS This invention was made with government support under Contract No. De-FG02-86ER13609 awarded by the Department of Energy. The Government has certain rights in this invention.

Development and applications of optical interferometric micrometrology in the angstrom and subangstrom range

NASA Technical Reports Server (NTRS)

Lauer, James L.; Abel, Phillip B.

1988-01-01

The recent development of the scanning electron tunneling microscope and the atomic force microscope requires absolute standards for measurements in the angstrom and subangstrom range. Optical interferometry with lasers and multiple mode laser resonances can provide absolute measurements as the laser wavelengths are very accurately known. A key feature of such measurements is the use of piezoelectric crystals as translators of the highest accuracy for very small disturbances. However, the dimensional changes of these crystals resulting from electrical potential changes depend on many variables, among them the method of mounting, so that accurate calibrations are necessary. Starting from advances in optical metrology made by physicists trying to find gravity waves, advances which led to measurements down to 10 to the -5 A, the author designed and built a much simpler system for the angstrom range. The major limiting factors were mechanical vibrations, air currents, thermal changes and laser instabilities.

A stereo-compound hybrid microscope for combined intracellular and optical recording of invertebrate neural network activity

PubMed Central

Frost, William N.; Wang, Jean; Brandon, Christopher J.

2007-01-01

Optical recording studies of invertebrate neural networks with voltage-sensitive dyes seldom employ conventional intracellular electrodes. This may in part be due to the traditional reliance on compound microscopes for such work. While such microscopes have high light-gathering power, they do not provide depth of field, making working with sharp electrodes difficult. Here we describe a hybrid microscope design, with switchable compound and stereo objectives, that eases the use of conventional intracellular electrodes in optical recording experiments. We use it, in combination with a voltage-sensitive dye and photodiode array, to identify neurons participating in the swim motor program of the marine mollusk Tritonia. This microscope design should be applicable to optical recording studies in many preparations. PMID:17306887

On-Chip Biomedical Imaging

PubMed Central

Göröcs, Zoltán; Ozcan, Aydogan

2012-01-01

Lab-on-a-chip systems have been rapidly emerging to pave the way toward ultra-compact, efficient, mass producible and cost-effective biomedical research and diagnostic tools. Although such microfluidic and micro electromechanical systems achieved high levels of integration, and are capable of performing various important tasks on the same chip, such as cell culturing, sorting and staining, they still rely on conventional microscopes for their imaging needs. Recently several alternative on-chip optical imaging techniques have been introduced, which have the potential to substitute conventional microscopes for various lab-on-a-chip applications. Here we present a critical review of these recently emerging on-chip biomedical imaging modalities, including contact shadow imaging, lensfree holographic microscopy, fluorescent on-chip microscopy and lensfree optical tomography. PMID:23558399

Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging.

PubMed

Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui

2018-01-01

We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Optical monitoring of neuronal activity at high frame rate with a digital random-access multiphoton (RAMP) microscope.

PubMed

Otsu, Yo; Bormuth, Volker; Wong, Jerome; Mathieu, Benjamin; Dugué, Guillaume P; Feltz, Anne; Dieudonné, Stéphane

2008-08-30

Two-photon microscopy offers the promise of monitoring brain activity at multiple locations within intact tissue. However, serial sampling of voxels has been difficult to reconcile with millisecond timescales characteristic of neuronal activity. This is due to the conflicting constraints of scanning speed and signal amplitude. The recent use of acousto-optic deflector scanning to implement random-access multiphoton microscopy (RAMP) potentially allows to preserve long illumination dwell times while sampling multiple points-of-interest at high rates. However, the real-life abilities of RAMP microscopy regarding sensitivity and phototoxicity issues, which have so far impeded prolonged optical recordings at high frame rates, have not been assessed. Here, we describe the design, implementation and characterisation of an optimised RAMP microscope. We demonstrate the application of the microscope by monitoring calcium transients in Purkinje cells and cortical pyramidal cell dendrites and spines. We quantify the illumination constraints imposed by phototoxicity and show that stable continuous high-rate recordings can be obtained. During these recordings the fluorescence signal is large enough to detect spikes with a temporal resolution limited only by the calcium dye dynamics, improving upon previous techniques by at least an order of magnitude.

Semimicroscopic, Lane-consistent nucleon-nucleus optical model potential up to 200 MeV

NASA Astrophysics Data System (ADS)

Bauge, Eric; Delaroche, Jean-Paul; Girod, Michel

2000-10-01

Our semimicroscopic optical model potential (E. Bauge et al., Phys. Rev. C 58), 1118 (1998). is re-evaluated in order to obtain a Lane-consistent description of (p,p), (n,n) and (p,n IAS) elastic scattering and reaction observables. The re-assessed nuclear matter interaction (which includes sizable renormalizations of the isovector potentials) is folded with microscopic HFB nuclear densities, producing OMPs that are free of adjustable parameters for nuclei with A >= 40. With Lane-consistency of the interaction, and the predictive nature of our HFB calculations, this scheme can be used to calculate observables for nuclei far from the stability line with good predictivity.

MTF measurements on real time for performance analysis of electro-optical systems

NASA Astrophysics Data System (ADS)

Stuchi, Jose Augusto; Signoreto Barbarini, Elisa; Vieira, Flavio Pascoal; dos Santos, Daniel, Jr.; Stefani, Mário Antonio; Yasuoka, Fatima Maria Mitsue; Castro Neto, Jarbas C.; Linhari Rodrigues, Evandro Luis

2012-06-01

The need of methods and tools that assist in determining the performance of optical systems is actually increasing. One of the most used methods to perform analysis of optical systems is to measure the Modulation Transfer Function (MTF). The MTF represents a direct and quantitative verification of the image quality. This paper presents the implementation of the software, in order to calculate the MTF of electro-optical systems. The software was used for calculating the MTF of Digital Fundus Camera, Thermal Imager and Ophthalmologic Surgery Microscope. The MTF information aids the analysis of alignment and measurement of optical quality, and also defines the limit resolution of optical systems. The results obtained with the Fundus Camera and Thermal Imager was compared with the theoretical values. For the Microscope, the results were compared with MTF measured of Microscope Zeiss model, which is the quality standard of ophthalmological microscope.

Closed loop adaptive optics for microscopy without a wavefront sensor

PubMed Central

Kner, Peter; Winoto, Lukman; Agard, David A.; Sedat, John W.

2013-01-01

A three-dimensional wide-field image of a small fluorescent bead contains more than enough information to accurately calculate the wavefront in the microscope objective back pupil plane using the phase retrieval technique. The phase-retrieved wavefront can then be used to set a deformable mirror to correct the point-spread function (PSF) of the microscope without the use of a wavefront sensor. This technique will be useful for aligning the deformable mirror in a widefield microscope with adaptive optics and could potentially be used to correct aberrations in samples where small fluorescent beads or other point sources are used as reference beacons. Another advantage is the high resolution of the retrieved wavefont as compared with current Shack-Hartmann wavefront sensors. Here we demonstrate effective correction of the PSF in 3 iterations. Starting from a severely aberrated system, we achieve a Strehl ratio of 0.78 and a greater than 10-fold increase in maximum intensity. PMID:24392198

An atomic force microscope for the study of the effects of tip sample interactions on dimensional metrology

NASA Astrophysics Data System (ADS)

Yacoot, Andrew; Koenders, Ludger; Wolff, Helmut

2007-02-01

An atomic force microscope (AFM) has been developed for studying interactions between the AFM tip and the sample. Such interactions need to be taken into account when making quantitative measurements. The microscope reported here has both the conventional beam deflection system and a fibre optical interferometer for measuring the movement of the cantilever. Both can be simultaneously used so as to not only servo control the tip movements, but also detect residual movement of the cantilever. Additionally, a high-resolution homodyne differential optical interferometer is used to measure the vertical displacement between the cantilever holder and the sample, thereby providing traceability for vertical height measurements. The instrument is compatible with an x-ray interferometer, thereby facilitating high resolution one-dimensional scans in the X-direction whose metrology is based on the silicon d220 lattice spacing (0.192 nm). This paper concentrates on the first stage of the instrument's development and presents some preliminary results validating the instrument's performance and showing its potential.

Evaluation of a completely robotized neurosurgical operating microscope.

PubMed

Kantelhardt, Sven R; Finke, Markus; Schweikard, Achim; Giese, Alf

2013-01-01

Operating microscopes are essential for most neurosurgical procedures. Modern robot-assisted controls offer new possibilities, combining the advantages of conventional and automated systems. We evaluated the prototype of a completely robotized operating microscope with an integrated optical coherence tomography module. A standard operating microscope was fitted with motors and control instruments, with the manual control mode and balance preserved. In the robot mode, the microscope was steered by a remote control that could be fixed to a surgical instrument. External encoders and accelerometers tracked microscope movements. The microscope was additionally fitted with an optical coherence tomography-scanning module. The robotized microscope was tested on model systems. It could be freely positioned, without forcing the surgeon to take the hands from the instruments or avert the eyes from the oculars. Positioning error was about 1 mm, and vibration faded in 1 second. Tracking of microscope movements, combined with an autofocus function, allowed determination of the focus position within the 3-dimensional space. This constituted a second loop of navigation independent from conventional infrared reflector-based techniques. In the robot mode, automated optical coherence tomography scanning of large surface areas was feasible. The prototype of a robotized optical coherence tomography-integrated operating microscope combines the advantages of a conventional manually controlled operating microscope with a remote-controlled positioning aid and a self-navigating microscope system that performs automated positioning tasks such as surface scans. This demonstrates that, in the future, operating microscopes may be used to acquire intraoperative spatial data, volume changes, and structural data of brain or brain tumor tissue.

On the importance of image formation optics in the design of infrared spectroscopic imaging systems

PubMed Central

Mayerich, David; van Dijk, Thomas; Walsh, Michael; Schulmerich, Matthew; Carney, P. Scott

2014-01-01

Infrared spectroscopic imaging provides micron-scale spatial resolution with molecular contrast. While recent work demonstrates that sample morphology affects the recorded spectrum, considerably less attention has been focused on the effects of the optics, including the condenser and objective. This analysis is extremely important, since it will be possible to understand effects on recorded data and provides insight for reducing optical effects through rigorous microscope design. Here, we present a theoretical description and experimental results that demonstrate the effects of commonly-employed cassegranian optics on recorded spectra. We first combine an explicit model of image formation and a method for quantifying and visualizing the deviations in recorded spectra as a function of microscope optics. We then verify these simulations with measurements obtained from spatially heterogeneous samples. The deviation of the computed spectrum from the ideal case is quantified via a map which we call a deviation map. The deviation map is obtained as a function of optical elements by systematic simulations. Examination of deviation maps demonstrates that the optimal optical configuration for minimal deviation is contrary to prevailing practice in which throughput is maximized for an instrument without a sample. This report should be helpful for understanding recorded spectra as a function of the optics, the analytical limits of recorded data determined by the optical design, and potential routes for optimization of imaging systems. PMID:24936526

On the importance of image formation optics in the design of infrared spectroscopic imaging systems.

PubMed

Mayerich, David; van Dijk, Thomas; Walsh, Michael J; Schulmerich, Matthew V; Carney, P Scott; Bhargava, Rohit

2014-08-21

Infrared spectroscopic imaging provides micron-scale spatial resolution with molecular contrast. While recent work demonstrates that sample morphology affects the recorded spectrum, considerably less attention has been focused on the effects of the optics, including the condenser and objective. This analysis is extremely important, since it will be possible to understand effects on recorded data and provides insight for reducing optical effects through rigorous microscope design. Here, we present a theoretical description and experimental results that demonstrate the effects of commonly-employed cassegranian optics on recorded spectra. We first combine an explicit model of image formation and a method for quantifying and visualizing the deviations in recorded spectra as a function of microscope optics. We then verify these simulations with measurements obtained from spatially heterogeneous samples. The deviation of the computed spectrum from the ideal case is quantified via a map which we call a deviation map. The deviation map is obtained as a function of optical elements by systematic simulations. Examination of deviation maps demonstrates that the optimal optical configuration for minimal deviation is contrary to prevailing practice in which throughput is maximized for an instrument without a sample. This report should be helpful for understanding recorded spectra as a function of the optics, the analytical limits of recorded data determined by the optical design, and potential routes for optimization of imaging systems.

Optical Tweezer Assembly and Calibration

NASA Technical Reports Server (NTRS)

Collins, Timothy M.

2004-01-01

An Optical Tweezer, as the name implies, is a useful tool for precision manipulation of micro and nano scale objects. Using the principle of electromagnetic radiation pressure, an optical tweezer employs a tightly focused laser beam to trap and position objects of various shapes and sizes. These devices can trap micrometer and nanometer sized objects. An exciting possibility for optical tweezers is its future potential to manipulate and assemble micro and nano sized sensors. A typical optical tweezer makes use of the following components: laser, mirrors, lenses, a high quality microscope, stage, Charge Coupled Device (CCD) camera, TV monitor and Position Sensitive Detectors (PSDs). The laser wavelength employed is typically in the visible or infrared spectrum. The laser beam is directed via mirrors and lenses into the microscope. It is then tightly focused by a high magnification, high numerical aperture microscope objective into the sample slide, which is mounted on a translating stage. The sample slide contains a sealed, small volume of fluid that the objects are suspended in. The most common objects trapped by optical tweezers are dielectric spheres. When trapped, a sphere will literally snap into and center itself in the laser beam. The PSD s are mounted in such a way to receive the backscatter after the beam has passed through the trap. PSD s used with the Differential Interference Contrast (DIC) technique provide highly precise data. Most optical tweezers employ lasers with power levels ranging from 10 to 100 miliwatts. Typical forces exerted on trapped objects are in the pico-newton range. When PSDs are employed, object movement can be resolved on a nanometer scale in a time range of milliseconds. Such accuracy, however, can only by utilized by calibrating the optical tweezer. Fortunately, an optical tweezer can be modeled accurately as a simple spring. This allows Hook s Law to be used. My goal this summer at NASA Glenn Research Center is the assembly and calibration of an optical tweezer setup in the Instrumentation and Controls Division (5520). I am utilizing a custom LabVIEW Virtual Instrument program for data collection and microscope stage control. Helping me in my assignment are the following people: Mentor Susan Wrbanek (5520), Dr. Baha Jassemnejad (UCO) and Technicians Ken Weiland (7650) and James Williams (7650). Without their help, my task would not be possible.

Isometric multimodal photoacoustic microscopy based on optically transparent micro-ring ultrasonic detection.

PubMed

Dong, Biqin; Li, Hao; Zhang, Zhen; Zhang, Kevin; Chen, Siyu; Sun, Cheng; Zhang, Hao F

2015-01-01

Photoacoustic microscopy (PAM) is an attractive imaging tool complementary to established optical microscopic modalities by providing additional molecular specificities through imaging optical absorption contrast. While the development of optical resolution photoacoustic microscopy (ORPAM) offers high lateral resolution, the acoustically-determined axial resolution is limited due to the constraint in ultrasonic detection bandwidth. ORPAM with isometric spatial resolution along both axial and lateral direction is yet to be developed. Although recently developed sophisticated optical illumination and reconstruction methods offer improved axial resolution in ORPAM, the image acquisition procedures are rather complicated, limiting their capabilities for high-speed imaging and being easily integrated with established optical microscopic modalities. Here we report an isometric ORPAM based on an optically transparent micro-ring resonator ultrasonic detector and a commercial inverted microscope platform. Owing to the superior spatial resolution and the ease of integrating our ORPAM with established microscopic modalities, single cell imaging with extrinsic fluorescence staining, intrinsic autofluorescence, and optical absorption can be achieved simultaneously. This technique holds promise to greatly improve the accessibility of PAM to the broader biomedical researchers.

Generic distortion model for metrology under optical microscopes

NASA Astrophysics Data System (ADS)

Liu, Xingjian; Li, Zhongwei; Zhong, Kai; Chao, YuhJin; Miraldo, Pedro; Shi, Yusheng

2018-04-01

For metrology under optical microscopes, lens distortion is the dominant source of error. Previous distortion models and correction methods mostly rely on the assumption that parametric distortion models require a priori knowledge of the microscopes' lens systems. However, because of the numerous optical elements in a microscope, distortions can be hardly represented by a simple parametric model. In this paper, a generic distortion model considering both symmetric and asymmetric distortions is developed. Such a model is obtained by using radial basis functions (RBFs) to interpolate the radius and distortion values of symmetric distortions (image coordinates and distortion rays for asymmetric distortions). An accurate and easy to implement distortion correction method is presented. With the proposed approach, quantitative measurement with better accuracy can be achieved, such as in Digital Image Correlation for deformation measurement when used with an optical microscope. The proposed technique is verified by both synthetic and real data experiments.

Curved adjustable fibre-optic diode laser in microscopic cholesteatoma surgery: description of use and review of the relevant literature.

PubMed

McCaffer, C J; Pabla, L; Watson, C

2018-04-01

The use of lasers in cholesteatoma surgery is common and well accepted. The most commonly used laser fibres are straight and non-adjustable; these have several limitations. This paper describes the use of an alternative laser fibre. This 'How I Do It' paper describes and illustrates the use of an alternative curved adjustable fibre-optic diode laser in microscopic cholesteatoma surgery. The curved, adjustable laser fibre allows accurate and atraumatic disease removal when the use of a straight laser fibre may be less effective or accurate. It reduces potential damage to delicate structures without the need for extra drilling or bone removal. It is suggested that the curved adjustable laser fibre is superior to the traditional straight fibre for cholesteatoma surgery.

Electronic and structural aspects of spin transitions observed by optical microscopy. The case of [Fe(ptz)6](BF4)2.

PubMed

Chong, Christian; Mishra, Haritosh; Boukheddaden, Kamel; Denise, Stéphane; Bouchez, Guillaume; Collet, Eric; Ameline, Jean-Claude; Naik, Anil D; Garcia, Yann; Varret, François

2010-02-11

The colorimetric analysis of images recorded with an optical microscope during the onset of the spin crossover transformation allows monitoring separately the involved electronic and structural aspects, through the separation of resonant absorption and scattering effects. Complementary information can also be obtained by using the polarized modes of the microscope. These potentialities are illustrated by the observation of [Fe(ptz)(6)](BF(4))(2) single crystals during the onset of the thermal transitions in the 110-140 K range. We characterized the interplay between the electronic (HS <--> LS) and structural (order <--> disorder) transformations. Elastic stresses and mechanical effects (hopping, self-cleavage) generated by the volume change upon electronic transition are also illustrated, with their impact on the photoswitching properties of the crystals.

Comprehensive study of unexpected microscope condensers formed in sample arrangements commonly used in optical microscopy.

PubMed

Desai, Darshan B; Aldawsari, Mabkhoot Mudith S; Alharbi, Bandar Mohammed H; Sen, Sanchari; Grave de Peralta, Luis

2015-09-01

We show that various setups for optical microscopy which are commonly used in biomedical laboratories behave like efficient microscope condensers that are responsible for observed subwavelength resolution. We present a series of experiments and simulations that reveal how inclined illumination from such unexpected condensers occurs when the sample is perpendicularly illuminated by a microscope's built-in white-light source. In addition, we demonstrate an inexpensive add-on optical module that serves as an efficient and lightweight microscope condenser. Using such add-on optical module in combination with a low-numerical-aperture objective lens and Fourier plane imaging microscopy technique, we demonstrate detection of photonic crystals with a period nearly eight times smaller than the Rayleigh resolution limit.

Hyperlens-array-implemented optical microscopy

NASA Astrophysics Data System (ADS)

Iwanaga, Masanobu

2014-08-01

Limit of resolution of conventional optical microscopes has never reached below 100 nm under visible light illumination. We show that numerically designed high-transmittance hyperlens array (HLA) is implemented in an optical microscope and works in practice for achieving one-shot-recording optical images of in-situ placed objects with sub 50 nm resolution in lateral direction. Direct resolution test employing well-defined nanopatterns proves that the HLA-implemented imaging is super-resolution optical microscopy, which works even under nW/mm2 visible illumination for objects. The HLA implementation makes the resolution of conventional microscopes one-scale higher, leading to the 1/10 illumination wavelength range, that is, mesoscopic range.

Foveal light exposure is increased at the time of removal of silicone oil with the potential for phototoxicity.

PubMed

Dogramaci, Mahmut; Williams, Katie; Lee, Ed; Williamson, Tom H

2013-01-01

There is sudden and dramatic visual function deterioration in 1-10 % of eyes filled with silicone oil at the time of removal of silicon oil. Transmission of high-energy blue light is increased in eyes filled with silicone oil. We sought to identify if increased foveal light exposure is a potential factor in the pathophysiology of the visual loss at the time of removal of silicone oil. A graphic ray tracing computer program and laboratory models were used to determine the effect of the intraocular silicone oil bubble size on the foveal illuminance at the time of removal of silicone oil under direct microscope light. The graphic ray tracing computer program revealed a range of optical vignetting effects created by different sizes of silicone oil bubble within the vitreous cavity giving rise to an uneven macular illumination. The laboratory model was used to quantify the variation of illuminance at the foveal region with different sizes of silicone oil bubble with in the vitreous cavity at the time of removal of silicon oil under direct microscope light. To substantiate the hypothesis of the light toxicity during removal of silicone oil, The outcome of oil removal procedures performed under direct microscope illumination in compared to those performed under blocked illumination. The computer program showed that the optical vignetting effect at the macula was dependent on the size of the intraocular silicone oil bubble. The laboratory eye model showed that the foveal illuminance followed a bell-shaped curve with 70 % greater illuminance demonstrated at with 50-60 % silicone oil fill. The clinical data identified five eyes with unexplained vision loss out of 114 eyes that had the procedure performed under direct microscope illumination compared to none out of 78 eyes that had the procedure under blocked illumination. Foveal light exposure, and therefore the potential for phototoxicity, is transiently increased at the time of removal of silicone oil. This is due to uneven macular illumination resulting from the optical vignetting effect of different silicone oil bubble sizes. The increase in foveal light exposure may be significant when the procedure is performed under bright operating microscope light on already stressed photoreceptors of an eye filled with silicon oil. We advocate the use of precautions, such as central shadow filter on the operating microscope light source to reduce foveal light exposure and the risk of phototoxicity at the time of removal of silicone oil. The graphic ray tracing computer program used in this study shows promise in eye modeling for future studies.

Optical design and system characterization of an imaging microscope at 121.6 nm

NASA Astrophysics Data System (ADS)

Gao, Weichuan; Finan, Emily; Kim, Geon-Hee; Kim, Youngsik; Milster, Thomas D.

2018-03-01

We present the optical design and system characterization of an imaging microscope prototype at 121.6 nm. System engineering processes are demonstrated through the construction of a Schwarzschild microscope objective, including tolerance analysis, fabrication, alignment, and testing. Further improvements on the as-built system with a correction phase plate are proposed and analyzed. Finally, the microscope assembly and the imaging properties of the prototype are demonstrated.

Large area fabrication of plasmonic nanoparticle grating structure by conventional scanning electron microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sudheer,, E-mail: sudheer@rrcat.gov.in; Tiwari, P.; Rai, V. N.

Plasmonic nanoparticle grating (PNG) structure of different periods has been fabricated by electron beam lithography using silver halide based transmission electron microscope film as a substrate. Conventional scanning electron microscope is used as a fabrication tool for electron beam lithography. Optical microscope and energy dispersive spectroscopy (EDS) have been used for its morphological and elemental characterization. Optical characterization is performed by UV-Vis absorption spectroscopic technique.

Classification of Salmonella Enterica serotypes with selective bands using visible/NIR hyperspectral imaging

USDA-ARS?s Scientific Manuscript database

Optical detection of foodborne bacteria such as Salmonella classifies bacteria by analyzing spectral data, and has potential for rapid detection. In this experiment hyperspectral microscopy is explored as a means for classifying five Salmonella serotypes. Initially, the microscope collects 89 spect...

Optical forces, torques, and force densities calculated at a microscopic level using a self-consistent hydrodynamics method

NASA Astrophysics Data System (ADS)

Ding, Kun; Chan, C. T.

2018-04-01

The calculation of optical force density distribution inside a material is challenging at the nanoscale, where quantum and nonlocal effects emerge and macroscopic parameters such as permittivity become ill-defined. We demonstrate that the microscopic optical force density of nanoplasmonic systems can be defined and calculated using the microscopic fields generated using a self-consistent hydrodynamics model that includes quantum, nonlocal, and retardation effects. We demonstrate this technique by calculating the microscopic optical force density distributions and the optical binding force induced by external light on nanoplasmonic dimers. This approach works even in the limit when the nanoparticles are close enough to each other so that electron tunneling occurs, a regime in which classical electromagnetic approach fails completely. We discover that an uneven distribution of optical force density can lead to a light-induced spinning torque acting on individual particles. The hydrodynamics method offers us an accurate and efficient approach to study optomechanical behavior for plasmonic systems at the nanoscale.

Ultrawidefield microscope for high-speed fluorescence imaging and targeted optogenetic stimulation.

PubMed

Werley, Christopher A; Chien, Miao-Ping; Cohen, Adam E

2017-12-01

The rapid increase in the number and quality of fluorescent reporters and optogenetic actuators has yielded a powerful set of tools for recording and controlling cellular state and function. To achieve the full benefit of these tools requires improved optical systems with high light collection efficiency, high spatial and temporal resolution, and patterned optical stimulation, in a wide field of view (FOV). Here we describe our 'Firefly' microscope, which achieves these goals in a Ø6 mm FOV. The Firefly optical system is optimized for simultaneous photostimulation and fluorescence imaging in cultured cells. All but one of the optical elements are commercially available, yet the microscope achieves 10-fold higher light collection efficiency at its design magnification than the comparable commercially available microscope using the same objective. The Firefly microscope enables all-optical electrophysiology ('Optopatch') in cultured neurons with a throughput and information content unmatched by other neuronal phenotyping systems. This capability opens possibilities in disease modeling and phenotypic drug screening. We also demonstrate applications of the system to voltage and calcium recordings in human induced pluripotent stem cell derived cardiomyocytes.

Ultrawidefield microscope for high-speed fluorescence imaging and targeted optogenetic stimulation

PubMed Central

Werley, Christopher A.; Chien, Miao-Ping; Cohen, Adam E.

2017-01-01

The rapid increase in the number and quality of fluorescent reporters and optogenetic actuators has yielded a powerful set of tools for recording and controlling cellular state and function. To achieve the full benefit of these tools requires improved optical systems with high light collection efficiency, high spatial and temporal resolution, and patterned optical stimulation, in a wide field of view (FOV). Here we describe our ‘Firefly’ microscope, which achieves these goals in a Ø6 mm FOV. The Firefly optical system is optimized for simultaneous photostimulation and fluorescence imaging in cultured cells. All but one of the optical elements are commercially available, yet the microscope achieves 10-fold higher light collection efficiency at its design magnification than the comparable commercially available microscope using the same objective. The Firefly microscope enables all-optical electrophysiology (‘Optopatch’) in cultured neurons with a throughput and information content unmatched by other neuronal phenotyping systems. This capability opens possibilities in disease modeling and phenotypic drug screening. We also demonstrate applications of the system to voltage and calcium recordings in human induced pluripotent stem cell derived cardiomyocytes. PMID:29296505

Optical path difference microscopy with a Shack-Hartmann wavefront sensor.

PubMed

Gong, Hai; Agbana, Temitope E; Pozzi, Paolo; Soloviev, Oleg; Verhaegen, Michel; Vdovin, Gleb

2017-06-01

In this Letter, we show that a Shack-Hartmann wavefront sensor can be used for the quantitative measurement of the specimen optical path difference (OPD) in an ordinary incoherent optical microscope, if the spatial coherence of the illumination light in the plane of the specimen is larger than the microscope resolution. To satisfy this condition, the illumination numerical aperture should be smaller than the numerical aperture of the imaging lens. This principle has been successfully applied to build a high-resolution reference-free instrument for the characterization of the OPD of micro-optical components and microscopic biological samples.

Design of small confocal endo-microscopic probe working under multiwavelength environment

NASA Astrophysics Data System (ADS)

Kim, Young-Duk; Ahn, MyoungKi; Gweon, Dae-Gab

2010-02-01

Recently, optical imaging system is widely used in medical purpose. By using optical imaging system specific diseases can be easily diagnosed at early stage because optical imaging system has high resolution performance and various imaging method. These methods are used to get high resolution image of human body and can be used to verify whether the cell is infected by virus. Confocal microscope is one of the famous imaging systems which is used for in-vivo imaging. Because most of diseases are accompanied with cellular level changes, doctors can diagnosis at early stage by observing the cellular image of human organ. Current research is focused in the development of endo-microscope that has great advantage in accessibility to human body. In this research, I designed small probe that is connected to confocal microscope through optical fiber bundle and work as endo-microscope. And this small probe is mainly designed to correct chromatic aberration to use various laser sources for both fluorescence type and reflection type confocal images. By using two kinds of laser sources at the same time we demonstrated multi-modality confocal endo-microscope.

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.

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.

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.

Microscopy imaging device with advanced imaging properties

DOEpatents

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

2017-04-25

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.

Optical Magnification Should Be Mandatory for Microsurgery: Scientific Basis and Clinical Data Contributing to Quality Assurance

PubMed Central

Schoeffl, Harald; Lazzeri, Davide; Schnelzer, Richard; Froschauer, Stefan M.

2013-01-01

Background Microsurgical techniques are considered standard procedures in reconstructive surgery. Although microsurgery by itself is defined as surgery aided by optical magnification, there are no guidelines for determining in which clinical situations a microscope or loupe should be used. Therefore, we conducted standardized experiments to objectively assess the impact of optical magnification in microsurgery. Methods Sixteen participants of microsurgical training courses had to complete 2 sets of experiments. Each set had to be performed with an unaided eye, surgical loupes, and a regular operating microscope. The first set of experiments included coaptation of a chicken femoral nerve, and the second set consisted of anastomosing porcine coronary arteries. Evaluation of the sutured nerves and vessels were performed by 2 experienced microsurgeons using an operating microscope. Results The 16 participants of the study completed all of the experiments. The nerve coaptation and vascular anastomoses exercises showed a direct relationship of error frequency and lower optical magnification, meaning that the highest number of microsurgical errors occurred with the unaided eye. For nerve coaptation, there was a strong relationship (P<0.05) between the number of mistakes and magnification, and this relationship was very strong (P<0.01) for vascular anastomoses. Conclusions We were able to prove that microsurgical success is directly related to optical magnification. The human eye's ability to discriminate potentially important anatomical structures is limited, which might be detrimental for clinical results. Although not legally mandatory, surgeries such as reparative surgery after hand trauma should be conducted with magnifying devices for achieving optimal patient outcomes. PMID:23532716

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.

Apertureless near-field/far-field CW two-photon microscope for biological and material imaging and spectroscopic applications.

PubMed

Nowak, Derek B; Lawrence, A J; Sánchez, Erik J

2010-12-10

We present the development of a versatile spectroscopic imaging tool to allow for imaging with single-molecule sensitivity and high spatial resolution. The microscope allows for near-field and subdiffraction-limited far-field imaging by integrating a shear-force microscope on top of a custom inverted microscope design. The instrument has the ability to image in ambient conditions with optical resolutions on the order of tens of nanometers in the near field. A single low-cost computer controls the microscope with a field programmable gate array data acquisition card. High spatial resolution imaging is achieved with an inexpensive CW multiphoton excitation source, using an apertureless probe and simplified optical pathways. The high-resolution, combined with high collection efficiency and single-molecule sensitive optical capabilities of the microscope, are demonstrated with a low-cost CW laser source as well as a mode-locked laser source.

Images from Phoenix's MECA Instruments

NASA Technical Reports Server (NTRS)

2008-01-01

The image on the upper left is from NASA's Phoenix Mars Lander's Optical Microscope after a sample informally called 'Sorceress' was delivered to its silicon substrate on the 38th Martian day, or sol, of the mission (July 2, 2008).

A 3D representation of the same sample is on the right, as seen by Phoenix's Atomic Force Microscope. This is 100 times greater magnification than the view from the Optical Microscope, and the most highly magnified image ever seen from another world.

The Optical Microscope and the Atomic Force Microscope are part of Phoenix's Microscopy, Electrochemistry and Conductivity Analyzer instrument.

The Atomic Force Microscope was developed by a Swiss-led consortium in collaboration with Imperial College London.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Design of a normal incidence multilayer imaging X-ray microscope

NASA Astrophysics Data System (ADS)

Shealy, David L.; Gabardi, David R.; Hoover, Richard B.; Walker, Arthur B. C., Jr.; Lindblom, Joakim F.

Normal incidence multilayer Cassegrain X-ray telescopes were flown on the Stanford/MSFC Rocket X-ray Spectroheliograph. These instruments produced high spatial resolution images of the sun and conclusively demonstrated that doubly reflecting multilayer X-ray optical systems are feasible. The images indicated that aplanatic imaging soft X-ray/EUV microscopes should be achievable using multilayer optics technology. A doubly reflecting normal incidence multilayer imaging X-ray microscope based on the Schwarzschild configuration has been designed. The design of the microscope and the results of the optical system ray trace analysis are discussed. High resolution aplanatic imaging X-ray microscopes using normal incidence multilayer X-ray mirrors should have many important applications in advanced X-ray astronomical instrumentation, X-ray lithography, biological, biomedical, metallurgical, and laser fusion research.

Purple sea urchin Strongylocentrotus purpuratus gamete manipulation using optical trapping and microfluidics

NASA Astrophysics Data System (ADS)

Chandsawangbhuwana, Charlie; Shi, Linda Z.; Zhu, Qingyuan; Berns, Michael W.

2013-04-01

A system has been developed that allows for optical and fluidic manipulation of gametes. The optical manipulation is performed by using a single-point gradient trap with a 40× oil immersion PH3 1.3 NA objective on a Zeiss inverted microscope. The fluidic manipulation is performed by using a custom microfluidic chamber designed to fit into the short working distance between the condenser and objective. The system is validated using purple sea urchin Strongylocentrotus purpuratus gametes and has the potential to be used for mammalian in vitro fertilization and animal husbandry.

Three-dimensional non-destructive optical evaluation of laser-processing performance using optical coherence tomography.

PubMed

Kim, Youngseop; Choi, Eun Seo; Kwak, Wooseop; Shin, Yongjin; Jung, Woonggyu; Ahn, Yeh-Chan; Chen, Zhongping

2008-06-01

We demonstrate the use of optical coherence tomography (OCT) as a non-destructive diagnostic tool for evaluating laser-processing performance by imaging the features of a pit and a rim. A pit formed on a material at different laser-processing conditions is imaged using both a conventional scanning electron microscope (SEM) and OCT. Then using corresponding images, the geometrical characteristics of the pit are analyzed and compared. From the results, we could verify the feasibility and the potential of the application of OCT to the monitoring of the laser-processing performance.

Three-dimensional non-destructive optical evaluation of laser-processing performance using optical coherence tomography

PubMed Central

Kim, Youngseop; Choi, Eun Seo; Kwak, Wooseop; Shin, Yongjin; Jung, Woonggyu; Ahn, Yeh-Chan; Chen, Zhongping

2014-01-01

We demonstrate the use of optical coherence tomography (OCT) as a non-destructive diagnostic tool for evaluating laser-processing performance by imaging the features of a pit and a rim. A pit formed on a material at different laser-processing conditions is imaged using both a conventional scanning electron microscope (SEM) and OCT. Then using corresponding images, the geometrical characteristics of the pit are analyzed and compared. From the results, we could verify the feasibility and the potential of the application of OCT to the monitoring of the laser-processing performance. PMID:24932051

Two-photon laser scanning microscopy with electrowetting-based prism scanning

PubMed Central

Supekar, Omkar D.; Ozbay, Baris N.; Zohrabi, Mo; Nystrom, Philip D.; Futia, Gregory L.; Restrepo, Diego; Gibson, Emily A.; Gopinath, Juliet T.; Bright, Victor M.

2017-01-01

Laser scanners are an integral part of high resolution biomedical imaging systems such as confocal or 2-photon excitation (2PE) microscopes. In this work, we demonstrate the utility of electrowetting on dielectric (EWOD) prisms as a lateral laser-scanning element integrated in a conventional 2PE microscope. To the best of our knowledge, this is the first such demonstration for EWOD prisms. EWOD devices provide a transmissive, low power consuming, and compact alternative to conventional adaptive optics, and hence this technology has tremendous potential. We demonstrate 2PE microscope imaging of cultured mouse hippocampal neurons with a FOV of 130 × 130 μm2 using EWOD prism scanning. In addition, we show simulations of the optical system with the EWOD prism, to evaluate the effect of propagating a Gaussian beam through the EWOD prism on the imaging quality. Based on the simulation results a beam size of 0.91 mm full width half max was chosen to conduct the imaging experiments, resulting in a numerical aperture of 0.17 of the imaging system. PMID:29296477

An estimate of biofilm properties using an acoustic microscope.

PubMed

Good, Morris S; Wend, Christopher F; Bond, Leonard J; Mclean, Jeffrey S; Panetta, Paul D; Ahmed, Salahuddin; Crawford, Susan L; Daly, Don S

2006-09-01

Noninvasive measurements over a biofilm, a three-dimensional (3-D) community of microorganisms immobilized at a substratum, were made using an acoustic microscope operating at frequencies up to 70 MHz. The microscope scanned a 2.5-mm by 2.5-mm region of a living biofilm having a nominal thickness of 100 microm. Spatial variation of surface heterogeneity, thickness, interior structure, and biomass were estimated. Thickness was estimated as the product of the speed of sound of the medium and the interim between the highest signal peak and that of the substratum plane without biofilm. The thickest portions of biofilm were 145 microm; however, slender structures attributed as streamers extended above, with one obtaining a 274-microm height above the substratum. Three-dimensional iso-contours of amplitude were used to estimate the internal structure of the biofilm. Backscatter amplitude was examined at five zones of increasing height from the substratum to examine biomass distribution. Ultrasound-based estimates of thickness were corroborated with optical microscopy. The experimental acoustic and optical systems, methods used to estimate biofilm properties, and potential applications for the resulting data are discussed.

In vivo fiber-optic confocal reflectance microscope with an injection-molded plastic miniature objective lens.

PubMed

Carlson, Kristen; Chidley, Matthew; Sung, Kung-Bin; Descour, Michael; Gillenwater, Ann; Follen, Michele; Richards-Kortum, Rebecca

2005-04-01

For in vivo optical diagnostic technologies to be distributed to the developed and developing worlds, optical imaging systems must be constructed of inexpensive components. We present a fiber-optic confocal reflectance microscope with a cost-effective injection-molded plastic miniature objective lens for in vivo imaging of human tissues in near real time. The measured lateral resolution is less than 2.2 microm, and the measured axial resolution is 10 microm. Confocal images of ex vivo cervical tissue biopsies and in vivo human lip taken at 15 frames/s demonstrate the microscope's capability of imaging cell morphology and tissue architecture.

DESIGN NOTE: From nanometre to millimetre: a feasibility study of the combination of scanning probe microscopy and combined optical and x-ray interferometry

NASA Astrophysics Data System (ADS)

Yacoot, Andrew; Koenders, Ludger

2003-09-01

This feasibility study investigates the potential combination of an x-ray interferometer and optical interferometer as a one-dimensional long range high resolution scanning stage for an atomic force microscope (AFM) in order to overcome the problems of non-linearity associated with conventional AFMs and interferometers. Preliminary results of measurements of the uniformity of the period of a grating used as a transfer standards show variations in period at the nanometre level.

Analytical model of the optical vortex microscope.

PubMed

Płocinniczak, Łukasz; Popiołek-Masajada, Agnieszka; Masajada, Jan; Szatkowski, Mateusz

2016-04-20

This paper presents an analytical model of the optical vortex scanning microscope. In this microscope the Gaussian beam with an embedded optical vortex is focused into the sample plane. Additionally, the optical vortex can be moved inside the beam, which allows fine scanning of the sample. We provide an analytical solution of the whole path of the beam in the system (within paraxial approximation)-from the vortex lens to the observation plane situated on the CCD camera. The calculations are performed step by step from one optical element to the next. We show that at each step, the expression for light complex amplitude has the same form with only four coefficients modified. We also derive a simple expression for the vortex trajectory of small vortex displacements.

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.

Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging

NASA Astrophysics Data System (ADS)

Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui

2018-01-01

We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis.

Development and applications of optical interferometric micrometrology in the Angstrom and subangstrom range

NASA Technical Reports Server (NTRS)

Lauer, James L.; Abel, Phillip B.

1988-01-01

The characteristics of the scanning tunneling microscope and atomic force microscope (AFM) are briefly reviewed, and optical methods, mainly interferometry, of sufficient resolution to measure AFM deflections are discussed. The methods include optical resonators, laser interferometry, multiple-beam interferometry, and evanescent wave detection. Experimental results using AFM are reviewed.

The relationship between morphological changes of lens epithelial cells and intraocular lens optic material.

PubMed

Majima, K

1998-01-01

To examine the morphological changes of lens epithelial cells (LECs) occurring directly beneath and at regions contacting various intraocular lens (IOL) optic materials, human LECs were cultured on human anterior lens capsules and were further incubated upon placing above the cells lens optics made of polymethylmethacrylate, silicone, and soft acrylic material. Observations as to the morphological changes of LECs under phase-contrast microscope and scanning electron microscope were performed on the 14th day of incubation. Gatherings of LECs were observed at regions contacting the soft acrylic material under phase-contrast microscope, and gatherings of LECs were observed accurately at the same regions mentioned above under scanning electron microscope. On the other hand, LECs in contact with two other optic materials did not show morphological changes. The results suggest that LECs attached to and proliferated on not only the anterior lens capsules but also the soft acrylic IOL optics. The model used in this study may be useful in studying the relationship between cellular movement of LECs and IOL optic material.

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.

Microstructure and optical properties of nanocrystalline Cu2O thin films prepared by electrodeposition.

PubMed

Jiang, Xishun; Zhang, Miao; Shi, Shiwei; He, Gang; Song, Xueping; Sun, Zhaoqi

2014-01-01

Cuprous oxide (Cu2O) thin films were prepared by using electrodeposition technique at different applied potentials (-0.1, -0.3, -0.5, -0.7, and -0.9 V) and were annealed in vacuum at a temperature of 100°C for 1 h. Microstructure and optical properties of these films have been investigated by X-ray diffractometer (XRD), field-emission scanning electron microscope (SEM), UV-visible (vis) spectrophotometer, and fluorescence spectrophotometer. The morphology of these films varies obviously at different applied potentials. Analyses from these characterizations have confirmed that these films are composed of regular, well-faceted, polyhedral crystallites. UV-vis absorption spectra measurements have shown apparent shift in optical band gap from 1.69 to 2.03 eV as the applied potential becomes more cathodic. The emission of FL spectra at 603 nm may be assigned as the near band-edge emission.

Acoustical nanometre-scale vibrations of live cells detected by a near-field optical setup

NASA Astrophysics Data System (ADS)

Piga, Rosaria; Micheletto, Ruggero; Kawakami, Yoichi

2007-04-01

The Scanning Near-field Optical Microscope (SNOM) is able to detect tiny vertical movement on the cell membrane in the range of only 1 nanometer or less, about 3 orders of magnitude better than conventional optical microscopes. Here we show intriguing data of cell membrane nanometer-scale dynamics associated to different phenomena of the cell’s The Scanning Near-field Optical Microscope (SNOM) is able to detect tiny vertical movement on the cell membrane in the range of only 1 nanometer or less, about 3 orders of magnitude better than conventional optical microscopes. Here we show intriguing data of cell membrane nanometer-scale dynamics associated to different phenomena of the cell’s life, such as cell cycle and cell death, on rat pheochromocytoma line PC12. Working in culture medium with alive and unperturbed samples, we could detect nanometer-sized movements; Fourier components revealed a clear distinct behavior associated to regulation of neurite outgrowth and changes on morphology after necrotic stimulus.

Auricular burns associated with operating microscope use during otologic surgery.

PubMed

Latuska, Richard F; Carlson, Matthew L; Neff, Brian A; Driscoll, Colin L; Wanna, George B; Haynes, David S

2014-02-01

To raise awareness of the potential hazard of auricular burns associated with operating microscope use during otologic surgery. Retrospective case series and summary of the Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience (MAUDE) database of voluntary adverse event reports pertaining to microscope related auricular thermal injuries. All patients who sustained auricular burns while using the operating microscope during otologic surgery at 2 tertiary academic referral centers. Surgical procedure, microscope model, intensity of illumination, length of procedure, focal length, location and severity of burn, and patient outcome. A total of 4 microscope-related auricular thermal injuries were identified from the authors' institutions. Additionally, 82 unique cases of soft tissue burns associated with the use of an operative microscope have been voluntarily reported to the FDA since 2004. A disproportionately large percent (∼ 30%) of these occurred within the field of otology, the majority of which were during tympanoplasty or tympanomastoidectomy procedures at focal length distances of 300 mm or less with xenon light source microscopes. Simultaneous advancements in light delivery technologies and lens optics have continued to improve the efficiency of the operating microscope; however, these improvements also increase the potential for thermal injuries. Although rare, a review of the FDA MAUDE database suggests that microscope-related soft tissue burns occur more frequently in otology than any other surgical specialty. A variety of factors may help explain this finding, including the unique anatomy of the external ear with thin skin and limited underlying adipose tissue. Preventative measures should be taken to decrease the risk of thermal injuries including use of the lowest comfortable light intensity, adjusting the aperture width to match the operative field, frequent wound irrigation, and covering exposed portions of the pinna with a moist surgical sponge.

Integrative advances for OCT-guided ophthalmic surgery and intraoperative OCT: microscope integration, surgical instrumentation, and heads-up display surgeon feedback.

PubMed

Ehlers, Justis P; Srivastava, Sunil K; Feiler, Daniel; Noonan, Amanda I; Rollins, Andrew M; Tao, Yuankai K

2014-01-01

To demonstrate key integrative advances in microscope-integrated intraoperative optical coherence tomography (iOCT) technology that will facilitate adoption and utilization during ophthalmic surgery. We developed a second-generation prototype microscope-integrated iOCT system that interfaces directly with a standard ophthalmic surgical microscope. Novel features for improved design and functionality included improved profile and ergonomics, as well as a tunable lens system for optimized image quality and heads-up display (HUD) system for surgeon feedback. Novel material testing was performed for potential suitability for OCT-compatible instrumentation based on light scattering and transmission characteristics. Prototype surgical instruments were developed based on material testing and tested using the microscope-integrated iOCT system. Several surgical maneuvers were performed and imaged, and surgical motion visualization was evaluated with a unique scanning and image processing protocol. High-resolution images were successfully obtained with the microscope-integrated iOCT system with HUD feedback. Six semi-transparent materials were characterized to determine their attenuation coefficients and scatter density with an 830 nm OCT light source. Based on these optical properties, polycarbonate was selected as a material substrate for prototype instrument construction. A surgical pick, retinal forceps, and corneal needle were constructed with semi-transparent materials. Excellent visualization of both the underlying tissues and surgical instrument were achieved on OCT cross-section. Using model eyes, various surgical maneuvers were visualized, including membrane peeling, vessel manipulation, cannulation of the subretinal space, subretinal intraocular foreign body removal, and corneal penetration. Significant iterative improvements in integrative technology related to iOCT and ophthalmic surgery are demonstrated.

Quantitatively characterizing the microstructural features of breast ductal carcinoma tissues in different progression stages by Mueller matrix microscope.

PubMed

Dong, Yang; Qi, Ji; He, Honghui; He, Chao; Liu, Shaoxiong; Wu, Jian; Elson, Daniel S; Ma, Hui

2017-08-01

Polarization imaging has been recognized as a potentially powerful technique for probing the microstructural information and optical properties of complex biological specimens. Recently, we have reported a Mueller matrix microscope by adding the polarization state generator and analyzer (PSG and PSA) to a commercial transmission-light microscope, and applied it to differentiate human liver and cervical cancerous tissues with fibrosis. In this paper, we apply the Mueller matrix microscope for quantitative detection of human breast ductal carcinoma samples at different stages. The Mueller matrix polar decomposition and transformation parameters of the breast ductal tissues in different regions and at different stages are calculated and analyzed. For more quantitative comparisons, several widely-used image texture feature parameters are also calculated to characterize the difference in the polarimetric images. The experimental results indicate that the Mueller matrix microscope and the polarization parameters can facilitate the quantitative detection of breast ductal carcinoma tissues at different stages.

Measurements and properties of ice particles and carbon dioxide bubbles in aqueous mixture utilizing optical techniques

NASA Astrophysics Data System (ADS)

Diallo, Amadou O.

Optical techniques are used to determine the size, shape and many other properties of particles ranging from the micro to a nano-level. These techniques have endless applications. This research is based on a project assigned by a "Vendor" that wants anonymity. The Leica optical microscope and the Dark Field Polarizing Metallurgical Microscope is used to determine the size and count of ice crystals (Vendors products) in multiple time frames. Since the ice temperature influences, its symmetry and the shape is subject to changes at room temperature (300 K) and the atmospheric pressure that is exerted on the ice crystals varies. The ice crystals are in a mixture of water, electrolytes and carbon dioxide with the optical spectroscopy (Qpod2) and Spectra suite, the optical density of the ice crystals is established from the absorbance and transmission measurements. The optical density in this case is also referred to as absorption; it is plotted with respect to a frequency (GHz), wavelength (nm) or Raman shift (1/cm) which shows the light colliding with the ice particles and CO2. Depending on the peaks positions, it is possible to profile the ice crystal sizes using a mean distribution plots. The region of absorbency wavelength expected for the ice is in the visible range; the water molecules in the (UV) Ultra-violet range and the CO2 in the (IR) infrared region. It is also possible to obtain the reflection and transmission output as a percentage change with the wavelengths ranging from 200 to 1100 nm. The refractive index of the ice can be correlated to the density based on the optical acoustic theorem, or Mie Scattering Theory. The viscosity of the ice crystals and the solutions from which the ice crystals are made of as well are recorded with the SV-10 viscometer. The baseline viscosity is used as reference and set lower than that of the ice crystals. The Zeta potential of the particles present in the mixture are approximated by first finding the viscosity of the solution where the pH level contribute to the surface charges, afterward use Stoke's diameter to compute the settling velocity of the bubbles, or alternatively record it under the microscope. With those parameters in hand the surface charge of the bubble (zeta potential) is approximated.

Determination of scattering structures from spatial coherence measurements.

PubMed

Zarubin, A M

1996-03-01

A new method of structure determination and microscopic imaging with short-wavelength radiations (charged particles, X-rays, neutrons), based on measurements of the modulus and the phase of the degree of spatial coherence of the scattered radiation, is developed. The underlying principle of the method--transfer of structural information about the scattering potential via spatial coherence of the secondary (scattering) source of radiation formed by this potential--is expressed by the generalization of the van Cittert-Zernike theorem to wave and particle scattering [A.M. Zarubin, Opt. Commun. 100 (1993) 491; Opt. Commun. 102 (1993) 543]. Shearing interferometric techniques are proposed for implementing the above measurements; the limits of spatial resolution attainable by reconstruction of the absolute square of a 3D scattering potential and its 2D projections from the measurements are analyzed. It is shown theoretically that 3D imaging with atomic resolution can be realized in a "synthetic aperture" electron or ion microscope and that a 3D resolution of about 6 nm can be obtained with a "synthetic aperture" X-ray microscope. A proof-of-principle optical experiment is presented.

Fluorescence fibre-optic confocal microscopy of skin in vivo: microscope and fluorophores.

PubMed

Suihko, Christian; Swindle, Lucinda D; Thomas, Steven G; Serup, Jørgen

2005-11-01

Fibre-optic confocal imaging in vivo is a new approach in the assessment of human skin. The objective is to describe a novel instrument and its operation and use in combination with fluorophores. The Stratum is a fibre-optic fluorescence confocal microscope especially developed for the study of skin and mucous membranes. The system is flexible and any body site can be studied with a hand-held scanner. The light source is a 488 nm argon ion laser. Horizontal (en face) images of the epidermis and outer dermis are produced with cellular resolution. Magnification is approximately 1000 x . Fluorescein sodium is routinely used as fluorophore (intradermal injection or application to the skin surface). This fluorophore is safe for human use in vivo, but other substances (rhodamine B, Acridine Orange, green fluorescent protein, curcumin) have also been studied. The instrument produces sharp images of epidermal cell layers from the epidermal surface to the sub-papillary dermis, with sub-cellular resolution. The scanner is flexible in use. The technique of intradermal fluorophore injection requires some skill. We consider this fibre-optic instrument a potentially important tool in skin research for non-invasive optical biopsy of primarily the epidermis. Present use is focussed on research applications, where the fluorophore distribution in the skin may illustrate morphological changes in the epidermis.

Measuring Roughnesses Of Optical Surfaces

NASA Technical Reports Server (NTRS)

Coulter, Daniel R.; Al-Jumaily, Gahnim A.; Raouf, Nasrat A.; Anderson, Mark S.

1994-01-01

Report discusses use of scanning tunneling microscopy and atomic force microscopy to measure roughnesses of optical surfaces. These techniques offer greater spatial resolution than other techniques. Report notes scanning tunneling microscopes and atomic force microscopes resolve down to 1 nm.

Hard X-Ray Scanning Microscope with Multilayer Laue Lens Nanofocusing Optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nazaretski, Evgeny

Evgeny Nazaretski, a physicist at Brookhaven Lab’s National Synchrotron Light Source II, spearheaded the development of a one-of-a-kind x-ray microscope with novel nanofocusing optics called multilayer Laue lenses.

The optics of microscope image formation.

PubMed

Wolf, David E

2013-01-01

Although geometric optics gives a good understanding of how the microscope works, it fails in one critical area, which is explaining the origin of microscope resolution. To accomplish this, one must consider the microscope from the viewpoint of physical optics. This chapter describes the theory of the microscope-relating resolution to the highest spatial frequency that a microscope can collect. The chapter illustrates how Huygens' principle or construction can be used to explain the propagation of a plane wave. It is shown that this limit increases with increasing numerical aperture (NA). As a corollary to this, resolution increases with decreasing wavelength because of how NA depends on wavelength. The resolution is higher for blue light than red light. Resolution is dependent on contrast, and the higher the contrast, the higher the resolution. This last point relates to issues of signal-to-noise and dynamic range. The use of video and new digital cameras has necessitated redefining classical limits such as those of Rayleigh's criterion. Copyright © 2007 Elsevier Inc. All rights reserved.

Comparisons between conventional optical imaging and parametric indirect microscopic imaging on human skin detection

NASA Astrophysics Data System (ADS)

Liu, Guoyan; Gao, Kun; Liu, Xuefeng; Ni, Guoqiang

2016-10-01

We report a new method, polarization parameters indirect microscopic imaging with a high transmission infrared light source, to detect the morphology and component of human skin. A conventional reflection microscopic system is used as the basic optical system, into which a polarization-modulation mechanics is inserted and a high transmission infrared light source is utilized. The near-field structural characteristics of human skin can be delivered by infrared waves and material coupling. According to coupling and conduction physics, changes of the optical wave parameters can be calculated and curves of the intensity of the image can be obtained. By analyzing the near-field polarization parameters in nanoscale, we can finally get the inversion images of human skin. Compared with the conventional direct optical microscope, this method can break diffraction limit and achieve a super resolution of sub-100nm. Besides, the method is more sensitive to the edges, wrinkles, boundaries and impurity particles.

Superresolving dendritic spine morphology with STED microscopy under holographic photostimulation

PubMed Central

Lauterbach, Marcel Andreas; Guillon, Marc; Desnos, Claire; Khamsing, Dany; Jaffal, Zahra; Darchen, François; Emiliani, Valentina

2016-01-01

Abstract. Emerging all-optical methods provide unique possibilities for noninvasive studies of physiological processes at the cellular and subcellular scale. On the one hand, superresolution microscopy enables observation of living samples with nanometer resolution. On the other hand, light can be used to stimulate cells due to the advent of optogenetics and photolyzable neurotransmitters. To exploit the full potential of optical stimulation, light must be delivered to specific cells or even parts of cells such as dendritic spines. This can be achieved with computer generated holography (CGH), which shapes light to arbitrary patterns by phase-only modulation. We demonstrate here in detail how CGH can be incorporated into a stimulated emission depletion (STED) microscope for photostimulation of neurons and monitoring of nanoscale morphological changes. We implement an original optical system to allow simultaneous holographic photostimulation and superresolution STED imaging. We present how synapses can be clearly visualized in live cells using membrane stains either with lipophilic organic dyes or with fluorescent proteins. We demonstrate the capabilities of this microscope to precisely monitor morphological changes of dendritic spines after stimulation. These all-optical methods for cell stimulation and monitoring are expected to spread to various fields of biological research in neuroscience and beyond. PMID:27413766

Ultrafast superresolution fluorescence imaging with spinning disk confocal microscope optics.

PubMed

Hayashi, Shinichi; Okada, Yasushi

2015-05-01

Most current superresolution (SR) microscope techniques surpass the diffraction limit at the expense of temporal resolution, compromising their applications to live-cell imaging. Here we describe a new SR fluorescence microscope based on confocal microscope optics, which we name the spinning disk superresolution microscope (SDSRM). Theoretically, the SDSRM is equivalent to a structured illumination microscope (SIM) and achieves a spatial resolution of 120 nm, double that of the diffraction limit of wide-field fluorescence microscopy. However, the SDSRM is 10 times faster than a conventional SIM because SR signals are recovered by optical demodulation through the stripe pattern of the disk. Therefore a single SR image requires only a single averaged image through the rotating disk. On the basis of this theory, we modified a commercial spinning disk confocal microscope. The improved resolution around 120 nm was confirmed with biological samples. The rapid dynamics of micro-tubules, mitochondria, lysosomes, and endosomes were observed with temporal resolutions of 30-100 frames/s. Because our method requires only small optical modifications, it will enable an easy upgrade from an existing spinning disk confocal to a SR microscope for live-cell imaging. © 2015 Hayashi and Okada. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Application of principal component analysis to multispectral-multimodal optical image analysis for malaria diagnostics.

PubMed

Omucheni, Dickson L; Kaduki, Kenneth A; Bulimo, Wallace D; Angeyo, Hudson K

2014-12-11

Multispectral imaging microscopy is a novel microscopic technique that integrates spectroscopy with optical imaging to record both spectral and spatial information of a specimen. This enables acquisition of a large and more informative dataset than is achievable in conventional optical microscopy. However, such data are characterized by high signal correlation and are difficult to interpret using univariate data analysis techniques. In this work, the development and application of a novel method which uses principal component analysis (PCA) in the processing of spectral images obtained from a simple multispectral-multimodal imaging microscope to detect Plasmodium parasites in unstained thin blood smear for malaria diagnostics is reported. The optical microscope used in this work has been modified by replacing the broadband light source (tungsten halogen lamp) with a set of light emitting diodes (LEDs) emitting thirteen different wavelengths of monochromatic light in the UV-vis-NIR range. The LEDs are activated sequentially to illuminate same spot of the unstained thin blood smears on glass slides, and grey level images are recorded at each wavelength. PCA was used to perform data dimensionality reduction and to enhance score images for visualization as well as for feature extraction through clusters in score space. Using this approach, haemozoin was uniquely distinguished from haemoglobin in unstained thin blood smears on glass slides and the 590-700 spectral range identified as an important band for optical imaging of haemozoin as a biomarker for malaria diagnosis. This work is of great significance in reducing the time spent on staining malaria specimens and thus drastically reducing diagnosis time duration. The approach has the potential of replacing a trained human eye with a trained computerized vision system for malaria parasite blood screening.

HIGH TEMPERATURE MICROSCOPE AND FURNACE

DOEpatents

Olson, D.M.

1961-01-31

A high-temperature microscope is offered. It has a reflecting optic situated above a molten specimen in a furnace and reflecting the image of the same downward through an inert optic member in the floor of the furnace, a plurality of spaced reflecting plane mirrors defining a reflecting path around the furnace, a standard microscope supported in the path of and forming the end terminus of the light path.

Fiber optic biofluorometer for physiological research on muscle slices

NASA Astrophysics Data System (ADS)

Belz, Mathias; Dendorfer, Andreas; Werner, Jan; Lambertz, Daniel; Klein, Karl-Friedrich

2016-03-01

A focus of research in cell physiology is the detection of Ca2+, NADH, FAD, ATPase activity or membrane potential, only to name a few, in muscle tissues. In this work, we report on a biofluorometer using ultraviolet light emitting diodes (UV-LEDs), optical fibers and two photomultipliers (PMTs) using synchronized fluorescence detection with integrated background correction to detect free calcium, Ca2+, in cardiac muscle tissue placed in a horizontal tissue bath and a microscope setup. Fiber optic probes with imaging optics have been designed to transport excitation light from the biofluorometer's light output to a horizontal tissue bath and to collect emission light from a tissue sample of interest to two PMTs allowing either single excitation / single emission or ratiometric, dual excitation / single emission or single excitation / dual emission fluorescence detection of indicator dyes or natural fluorophores. The efficient transport of light from the excitation LEDs to the tissue sample, bleaching effects of the excitation light in both, polymer and fused silica-based fibers will be discussed. Furthermore, a new approach to maximize light collection of the emission light using high NA fibers and high NA coupling optics will be shown. Finally, first results on Ca2+ measurements in cardiac muscle slices in a traditional microscope setup and a horizontal tissue bath using fiber optic probes will be introduced and discussed.

Scanning tunneling microscopy and atomic force microscopy: application to biology and technology.

PubMed

Hansma, P K; Elings, V B; Marti, O; Bracker, C E

1988-10-14

The scanning tunneling microscope (STM) and the atomic force microscope (AFM) are scanning probe microscopes capable of resolving surface detail down to the atomic level. The potential of these microscopes for revealing subtle details of structure is illustrated by atomic resolution images including graphite, an organic conductor, an insulating layered compound, and individual adsorbed oxygen atoms on a semiconductor. Application of the STM for imaging biological materials directly has been hampered by the poor electron conductivity of most biological samples. The use of thin conductive metal coatings and replicas has made it possible to image some biological samples, as indicated by recently obtained images of a recA-DNA complex, a phospholipid bilayer, and an enzyme crystal. The potential of the AFM, which does not require a conductive sample, is shown with molecular resolution images of a nonconducting organic monolayer and an amino acid crystal that reveals individual methyl groups on the ends of the amino acids. Applications of these new microscopes to technology are demonstrated with images of an optical disk stamper, a diffraction grating, a thin-film magnetic recording head, and a diamond cutting tool. The STM has even been used to improve the quality of diffraction gratings and magnetic recording heads.

Sedimentological Investigations of the Martian Surface using the Mars 2001 Robotic Arm Camera and MECA Optical Microscope

NASA Technical Reports Server (NTRS)

Rice, J. W., Jr.; Smith, P. H.; Marshall, J. R.

1999-01-01

The first microscopic sedimentological studies of the Martian surface will commence with the landing of the Mars Polar Lander (MPL) December 3, 1999. The Robotic Arm Camera (RAC) has a resolution of 25 um/p which will permit detailed micromorphological analysis of surface and subsurface materials. The Robotic Ann will be able to dig up to 50 cm below the surface. The walls of the trench will also be inspected by RAC to look for evidence of stratigraphic and / or sedimentological relationships. The 2001 Mars Lander will build upon and expand the sedimentological research begun by the RAC on MPL. This will be accomplished by: (1) Macroscopic (dm to cm): Descent Imager, Pancam, RAC; (2) Microscopic (mm to um RAC, MECA Optical Microscope (Figure 2), AFM This paper will focus on investigations that can be conducted by the RAC and MECA Optical Microscope.

Hard X-Ray Scanning Microscope with Multilayer Laue Lens Nanofocusing Optics

ScienceCinema

Nazaretski, Evgeny

2018-06-13

Evgeny Nazaretski, a physicist at Brookhaven Lab’s National Synchrotron Light Source II, spearheaded the development of a one-of-a-kind x-ray microscope with novel nanofocusing optics called multilayer Laue lenses.

High-energy proton imaging for biomedical applications

DOE PAGES

Prall, Matthias; Durante, Marco; Berger, Thomas; ...

2016-06-10

The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allowsmore » imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. As a result, tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.« less

High-energy proton imaging for biomedical applications

NASA Astrophysics Data System (ADS)

Prall, M.; Durante, M.; Berger, T.; Przybyla, B.; Graeff, C.; Lang, P. M.; Latessa, C.; Shestov, L.; Simoniello, P.; Danly, C.; Mariam, F.; Merrill, F.; Nedrow, P.; Wilde, C.; Varentsov, D.

2016-06-01

The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allows imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. Tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.

High-energy proton imaging for biomedical applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prall, Matthias; Durante, Marco; Berger, Thomas

The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allowsmore » imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. As a result, tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.« less

A compact CCD-monitored atomic force microscope with optical vision and improved performances.

PubMed

Mingyue, Liu; Haijun, Zhang; Dongxian, Zhang

2013-09-01

A novel CCD-monitored atomic force microscope (AFM) with optical vision and improved performances has been developed. Compact optical paths are specifically devised for both tip-sample microscopic monitoring and cantilever's deflection detecting with minimized volume and optimal light-amplifying ratio. The ingeniously designed AFM probe with such optical paths enables quick and safe tip-sample approaching, convenient and effective tip-sample positioning, and high quality image scanning. An image stitching method is also developed to build a wider-range AFM image under monitoring. Experiments show that this AFM system can offer real-time optical vision for tip-sample monitoring with wide visual field and/or high lateral optical resolution by simply switching the objective; meanwhile, it has the elegant performances of nanometer resolution, high stability, and high scan speed. Furthermore, it is capable of conducting wider-range image measurement while keeping nanometer resolution. Copyright © 2013 Wiley Periodicals, Inc.

Optical anisotropy of the human cornea determined with a polarizing microscope.

PubMed

Bone, Richard A; Draper, Grenville

2007-12-01

We have investigated the optical anisotropy of the human cornea using a polarizing microscope normally used for optical mineralogy studies. The central part of the cornea was removed from 14 eyes (seven donors). With the sample placed on the microscope stage, we consistently observed hyperbolic isogyres characteristic of a negative biaxial material. The angle between the optic axes, generally similar in both eyes, ranged from 12 degrees to 40 degrees (mean+/-SD=31 degrees +/-8 degrees ). The optic axial plane always inclined downward in the nasal direction at 1 degrees -45 degrees below the horizontal (mean+/-SD=22+/-13 degrees ). The retardance produced by the corneas was estimated to be less than 200 nm. In conclusion, the human cornea possesses the anisotropy of a negative biaxial material. Both the angle between the optic axes and the retardance were fairly constant among the majority of samples, suggestive of uniformity in corneal structure.

Precise measurement of surface plasmon forces at a metal-dielectric interface using a calibrated evanescent wave

NASA Astrophysics Data System (ADS)

Liu, Lulu; Woolf, Alex

2015-03-01

By observing the motion of an optically trapped microscopic colloid, sub-piconewton static and dynamical forces have been measured using a technique called photonic force microscopy. This technique, though potentially powerful, has in the past struggled to make precise measurements in the vicinity of a reflective or metallic interface, due to distortions of the optical field. We introduce a new in-situ, contact-free calibration method for particle tracking using an evanescent wave, and demonstrate its expanded capability by the precise measurement of forces of interaction between a single colloid and the optical field generated by a propagating surface plasmon polariton on gold.

DotLens smartphone microscopy for biological and biomedical applications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Sung, Yu-Lung; Zhao, Fusheng; Shih, Wei-Chuan

2017-02-01

Recent advances in inkjet-printed optics have created a new class of lens fabrication technique. Lenses with a tunable geometry, magnification, and focal length can be fabricated by dispensing controlled amounts of liquid polymer onto a heated surface. This fabrication technique is highly cost-effective, and can achieve optically smooth surface finish. Dubbed DotLens, a single of which weighs less than 50 mg and occupies a volume less than 50 μL. DotLens can be attached onto any smartphone camera akin to a contact lens, and enable smartphones to obtain image resolution as fine as 1 µm. The surface curvature modifies the optical path of light to the image sensor, and enables the camera to focus as close as 2 mm. This enables microscopic imaging on a smartphone without any additional attachments, and has shown great potential in mobile point-of-care diagnostic systems, particularly for histology of tissue sections and cytology of blood cells. DotLens Smartphone Microscopy represents an innovative approach fundamentally different from other smartphone microscopes. In this paper, we describe the application and performance of DotLens smartphone microscopy in biological and biomedical research. In particular, we show recent results from images collected from pathology tissue slides with cancer features. In addition, we show performance in cytological analysis of blood smear. This tool has empowered Citizen Science investigators to collect microscopic images from various interesting objects.

Design of an imaging microscope for soft X-ray applications

NASA Astrophysics Data System (ADS)

Hoover, Richard B.; Shealy, David L.; Gabardi, David R.; Walker, Arthur B. C., Jr.; Lindblom, Joakim F.

1988-01-01

An imaging soft X-ray microscope with a spatial resolution of 0.1 micron and normal incidence multilayer optics is discussed. The microscope has a Schwarzschild configuration, which consists of two concentric spherical mirrors with radii of curvature which minimize third-order spherical aberration, coma, and astigmatism. The performance of the Stanford/MSFC Cassegrain X-ray telescope and its relevance to the present microscope are addressed. A ray tracing analysis of the optical system indicates that diffraction-limited performance can be expected for an object height of 0.2 mm.

Sub-25-nm laboratory x-ray microscopy using a compound Fresnel zone plate.

PubMed

von Hofsten, Olov; Bertilson, Michael; Reinspach, Julia; Holmberg, Anders; Hertz, Hans M; Vogt, Ulrich

2009-09-01

Improving the resolution in x-ray microscopes is of high priority to enable future applications in nanoscience. However, high-resolution zone-plate optics often have low efficiency, which makes implementation in laboratory microscopes difficult. We present a laboratory x-ray microscope based on a compound zone plate. The compound zone plate utilizes multiple diffraction orders to achieve high resolution while maintaining reasonable efficiency. We analyze the illumination conditions necessary for this type of optics in order to suppress stray light and demonstrate microscopic imaging resolving 25 nm features.

Internal scanning method as unique imaging method of optical vortex scanning microscope

NASA Astrophysics Data System (ADS)

Popiołek-Masajada, Agnieszka; Masajada, Jan; Szatkowski, Mateusz

2018-06-01

The internal scanning method is specific for the optical vortex microscope. It allows to move the vortex point inside the focused vortex beam with nanometer resolution while the whole beam stays in place. Thus the sample illuminated by the focused vortex beam can be scanned just by the vortex point. We show that this method enables high resolution imaging. The paper presents the preliminary experimental results obtained with the first basic image recovery procedure. A prospect of developing more powerful tools for topography recovery with the optical vortex scanning microscope is discussed shortly.

High-resolution microscope for tip-enhanced optical processes in ultrahigh vacuum

NASA Astrophysics Data System (ADS)

Steidtner, Jens; Pettinger, Bruno

2007-10-01

An optical microscope based on tip-enhanced optical processes that can be used for studies on adsorbates as well as thin layers and nanostructures is presented. The microscope provides chemical and topographic informations with a resolution of a few nanometers and can be employed in ultrahigh vacuum as well as gas phase. The construction involves a number of improvements compared to conventional instruments. The central idea is to mount, within an UHV system, an optical platform with all necessary optical elements to a rigid frame that also carries the scanning tunneling microscope unit and to integrate a high numerical aperture parabolic mirror between the scanning probe microscope head and the sample. The parabolic mirror serves to focus the incident light and to collect a large fraction of the scattered light. The first experimental results of Raman measurements on silicon samples as well as brilliant cresyl blue layers on single crystalline gold and platinum surfaces in ultrahigh vacuum are presented. For dye adsorbates a Raman enhancement of ˜106 and a net signal gain of up to 4000 was observed. The focus diameter (˜λ/2) was measured by Raman imaging the focal region on a Si surface. The requirements of the parabolic mirror in terms of alignment accuracy were experimentally determined as well.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prabhakaran, Ramprashad; Joshi, Vineet V.; Rhodes, Mark 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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prabhakaran, Ramprashad; Joshi, Vineet V.; Rhodes, Mark 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.

On the influence of lipid-induced optical anisotropy for the bioimaging of exo- or endocytosis with interference microscopic imaging.

PubMed

Marques, D; Miranda, A; Silva, A G; Munro, P R T; DE Beule, P A A

2018-05-01

Some implementations of interference microscopy imaging use digital holographic measurements of complex scattered fields to reconstruct three-dimensional refractive index maps of weakly scattering, semi-transparent objects, frequently encountered in biological investigations. Reconstruction occurs through application of the object scattering potential which assumes an isotropic refractive index throughout the object. Here, we demonstrate that this assumption can in some circumstances be invalid for biological imaging due to the presence of lipid-induced optical anisotropy. We show that the nanoscale organization of lipids in the observation of cellular endocytosis with polarized light induces a significant change in far-field scattering. We obtain this result by presenting a general solution to Maxwell's equations describing light scattering of core-shell particles near an isotropic substrate covered with an anisotropic thin film. This solution is based on an extension of the Bobbert-Vlieger solution for particle scattering near a substrate delivering an exact solution to the scattering problem in the near field as well as far field. By applying this solution to study light scattering by a lipid vesicle near a lipid bilayer, whereby the lipids are represented through a biaxial optical model, we conclude through ellipsometry concepts that effective amounts of lipid-induced optical anisotropy significantly alter far-field optical scattering in respect to an equivalent optical model that neglects the presence of optical anisotropy. © 2018 The Authors Journal of Microscopy © 2018 Royal Microscopical Society.

Investigation of the potential of optical coherence tomography (OCT) as a non-invasive diagnostic tool in reproductive medicine

NASA Astrophysics Data System (ADS)

Trottmann, Matthias; Homann, Christian; Leeb, R.; Doering, D.; Kuznetsova, J.; Reese, S.; Stief, C. G.; Koelle, S.; Sroka, R.

2015-02-01

Introduction and objective: In Europe, nearly every sixth couple in the reproductive age is involuntarily childless. In about 30%, both male and female reveal fertility problems. In about 10% of infertile men, azoospermia is the underlying cause. As conventional therapeutic options are limited, surgical testicular sperm extraction (TESE) is necessary to obtain sperms for assisted reproductive techniques. Regarding the females, up to 30% of all idiopathic infertilities are due to alterations of the uterine tube So far, no imaging technique, which does not require any labelling, is available to evaluate the male and female genital tract at a microscopic level under in vivo conditions. Thus, the aim of this study was to investigate the potential of optical coherence tomography (OCT) as a non-invasive diagnostic tool in gynaecology and andrology. Material and Methods: Tissues samples from the bovine testis, epididymis, vas deferens, ovary, oviduct (ampulla and isthmus) and uterus were obtained immediately after slaughter (14 cows aged 3 to 8 years and 14 bulls aged 3 to 6 years; breeds: Holstein- Friesian, and Deutsches Fleckvieh). Imaging was done by using the US Food and Drug Administration (FDA) approved probe-based Niris Imaging System (Imalux, Cleveland, Ohio, USA) and the Telesto 1325 nm OCT System and Ganymede 930 nm OCT System (Thorlabs Inc., Dachau, Germany). All images obtained were compared to histological images after paraffin embedding and HE staining. Results: OCT imaging visualized the microarchitecture of the testis, epididymis, spermatic duct and the ovary, oviduct and uterus. Using the Thorlabs systems a axial resolution of approx. 5μm and lateral resolution of 8- 15μm could be achieved. Different optical tissue volumes could be visualized, which depends on the optical penetration depth of the wavelength of the system used. While the tissue volume observed by probe based Imalux-OCT is similar to the used Thorlabs systems, the optical resolution is reduced. By means of the microscopic OCT-system differentiation of testical tissue structures like content and diameter of seminiferous tubules and the epididymal duct was possible. Structures of the female oviduct, like the primary, secondary and tertiary folds including the typical epithelium consisting of secretory and ciliated cells were identified. Ampulla and isthmus were clearly differentiated by the height of the folds and the thickness of the smooth muscle layer. Imaging was successful both from the outside wall and from the inner lumen. After experience with microscopic OCT-structure identification such structures could also be identified by means of probe based OCT. Conclusions: Technical improvement of probe-based OCT up to a high-resolution level of nowadays-available OCT microscopic systems could open up new ways of in vivo imaging in the reproductive tract. Potential applications could be an OCT-guided testicular biopsy for improving sperm retrieval or microscopic evaluation of the oviduct by OCT-assisted fertiloscopy. The latter would provide a valuable tool to facilitate the decision of which type of assisted reproductive techniques might be preferred.

Micropaleontological studies of lunar and terrestrial precambrian materials

NASA Technical Reports Server (NTRS)

Schope, J. W.

1974-01-01

Optical microscopic and scanning electron microscopic studies of rock chips and dust returned by Apollo 14, 15, 16, and 17 are analyzed along with optical microscopic studies of petrographic thin sections of breccias and basalts returned by Apollo 14, 15, and 16. Results show no evidence of modern or fossil lunar organisms. The lunar surface is now, and apparently has been throughout the geologic past, inimical to known biologic systems.

Increasing Student Understanding of Microscope Optics by Building and Testing the Limits of Simple, Hand-Made Model Microscopes†

PubMed Central

Drace, Kevin; Couch, Brett; Keeling, Patrick J.

2012-01-01

The ability to effectively use a microscope to observe microorganisms is a crucial skill required for many disciplines within biology, especially general microbiology and cell biology. A basic understanding of the optical properties of light microscopes is required for students to use microscopes effectively, but this subject can also be a challenge to make personally interesting to students. To explore basic optical principles of magnification and resolving power in a more engaging and hands-on fashion, students constructed handmade lenses and microscopes based on Antony van Leeuwenhoek’s design using simple materials—paper, staples, glass, and adhesive putty. Students determined the power of their lenses using a green laser pointer to magnify a copper grid of known size, which also allowed students to examine variables affecting the power and resolution of a lens such as diameter, working distance, and wavelength of light. To assess the effectiveness of the laboratory’s learning objectives, four sections of a general microbiology course were given a brief pre-activity assessment quiz to determine their background knowledge on the subject. One week after the laboratory activity, students were given the same quiz (unannounced) under similar conditions. Students showed significant gains in their understanding of microscope optics. PMID:23653781

A hybrid scanning force and light microscope for surface imaging and three-dimensional optical sectioning in differential interference contrast.

PubMed

Stemmer, A

1995-04-01

The design of a scanned-cantilever-type force microscope is presented which is fully integrated into an inverted high-resolution video-enhanced light microscope. This set-up allows us to acquire thin optical sections in differential interference contrast (DIC) or polarization while the force microscope is in place. Such a hybrid microscope provides a unique platform to study how cell surface properties determine, or are affected by, the three-dimensional dynamic organization inside the living cell. The hybrid microscope presented in this paper has proven reliable and versatile for biological applications. It is the only instrument that can image a specimen by force microscopy and high-power DIC without having either to translate the specimen or to remove the force microscope. Adaptation of the design features could greatly enhance the suitability of other force microscopes for biological work.

A fast low-power optical memory based on coupled micro-ring lasers

NASA Astrophysics Data System (ADS)

Hill, Martin T.; Dorren, Harmen J. S.; de Vries, Tjibbe; Leijtens, Xaveer J. M.; den Besten, Jan Hendrik; Smalbrugge, Barry; Oei, Yok-Siang; Binsma, Hans; Khoe, Giok-Djan; Smit, Meint K.

2004-11-01

The increasing speed of fibre-optic-based telecommunications has focused attention on high-speed optical processing of digital information. Complex optical processing requires a high-density, high-speed, low-power optical memory that can be integrated with planar semiconductor technology for buffering of decisions and telecommunication data. Recently, ring lasers with extremely small size and low operating power have been made, and we demonstrate here a memory element constructed by interconnecting these microscopic lasers. Our device occupies an area of 18 × 40µm2 on an InP/InGaAsP photonic integrated circuit, and switches within 20ps with 5.5fJ optical switching energy. Simulations show that the element has the potential for much smaller dimensions and switching times. Large numbers of such memory elements can be densely integrated and interconnected on a photonic integrated circuit: fast digital optical information processing systems employing large-scale integration should now be viable.

The head-mounted microscope.

PubMed

Chen, Ting; Dailey, Seth H; Naze, Sawyer A; Jiang, Jack J

2012-04-01

Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300 mm to 700 mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Microscopic modeling of direct pre-equilibrium emission from neutron induced reactions on even and odd actinides

NASA Astrophysics Data System (ADS)

Dupuis, M.; Hilaire, S.; Péru, S.; Bauge, E.; Kerveno, M.; Dessagne, P.; Henning, G.

2017-09-01

Direct inelastic scattering to discrete excitations and pre-equilibrium emission are described within a microscopic model. Nuclear structure information are obtained in the (Quasi) Random Phase Approximation ((Q)RPA) framework implemented with the Gogny force. The relevant optical and transition potentials are build considering the JLM folding model. Various successful applications are shown for (n,n), (n,n'), (n,xn) and (n,xnγ) reactions for spherical and axially deformed even-even or odd targets. The rearrangement corrections to transition potentials and the contribution of unnatural parity excitations to pre-equilibrium emission are discussed. Our model predictions for (n,n'γ) reactions, for intra- and inter-band transitions in 238U, and for the 239Pu(n,2n) cross section are analyzed.

Membrane Mirrors With Bimorph Shape Actuators

NASA Technical Reports Server (NTRS)

Yang, Eui-Hyeok

2003-01-01

Deformable mirrors of a proposed type would be equipped with relatively-large-stroke microscopic piezoelectric actuators that would be used to maintain their reflective surfaces in precise shapes. These mirrors would be members of the class of MEMS-DM (for microelectromechanical system deformable mirror) devices, which offer potential for a precise optical control in adaptive-optics applications in such diverse fields as astronomy and vision science. The proposed mirror would be fabricated, in part, by use of a membrane-transfer technique. The actuator design would contain bimorph-type piezoelectric actuators.

A novel strategy towards designing a CdSe quantum dot-metallohydrogel composite material.

PubMed

Chatterjee, Sayantan; Maitra, Uday

2016-08-11

We have described here an efficient method to disperse hydrophobic CdSe quantum dots (QDs) in an aqueous phase using cetyltrimethylammonium bromide (CTAB) micelles without any surface ligand exchange. The water soluble QDs were then embedded in 3D self assembled fibrillar networks (SAFINs) of a hydrogel showing homogeneous dispersibility as evidenced from optical and electron microscopic techniques. The photophysical studies of the hydrogel-QD composite are reported for the first time. These composite materials may have potential applications in biology, optoelectronics, sensors, non-linear optics and materials science.

Water window imaging x ray microscope

NASA Technical Reports Server (NTRS)

Hoover, Richard B. (Inventor)

1992-01-01

A high resolution x ray microscope for imaging microscopic structures within biological specimens has an optical system including a highly polished primary and secondary mirror coated with identical multilayer coatings, the mirrors acting at normal incidence. The coatings have a high reflectivity in the narrow wave bandpass between 23.3 and 43.7 angstroms and have low reflectivity outside of this range. The primary mirror has a spherical concave surface and the secondary mirror has a spherical convex surface. The radii of the mirrors are concentric about a common center of curvature on the optical axis of the microscope extending from the object focal plane to the image focal plane. The primary mirror has an annular configuration with a central aperture and the secondary mirror is positioned between the primary mirror and the center of curvature for reflecting radiation through the aperture to a detector. An x ray filter is mounted at the stage end of the microscope, and film sensitive to x rays in the desired band width is mounted in a camera at the image plane of the optical system. The microscope is mounted within a vacuum chamber for minimizing the absorption of x rays in air from a source through the microscope.

Potential Engineering of Fermi-Hubbard Systems using a Quantum Gas Microscope

NASA Astrophysics Data System (ADS)

Ji, Geoffrey; Mazurenko, Anton; Chiu, Christie; Parsons, Maxwell; Kanász-Nagy, Márton; Schmidt, Richard; Grusdt, Fabian; Demler, Eugene; Greif, Daniel; Greiner, Markus

2017-04-01

Arbitrary control of optical potentials has emerged as an important tool in manipulating ultracold atomic systems, especially when combined with the single-site addressing afforded by quantum gas microscopy. Already, experiments have used digital micromirror devices (DMDs) to initialize and control ultracold atomic systems in the context of studying quantum walks, quantum thermalization, and many-body localization. Here, we report on progress in using a DMD located in the image plane of a quantum gas microscope to explore static and dynamic properties of a 2D Fermi-Hubbard system. By projecting a large, ring-shaped anti-confining potential, we demonstrate entropy redistribution and controlled doping of the system. Moreover, we use the DMD to prepare localized holes, which upon release interact with and disrupt the surrounding spin environment. These techniques pave the way for controlled investigations of dynamics in the low-temperature phases of the Hubbard model.

Integrative Advances for OCT-Guided Ophthalmic Surgery and Intraoperative OCT: Microscope Integration, Surgical Instrumentation, and Heads-Up Display Surgeon Feedback

PubMed Central

Ehlers, Justis P.; Srivastava, Sunil K.; Feiler, Daniel; Noonan, Amanda I.; Rollins, Andrew M.; Tao, Yuankai K.

2014-01-01

Purpose To demonstrate key integrative advances in microscope-integrated intraoperative optical coherence tomography (iOCT) technology that will facilitate adoption and utilization during ophthalmic surgery. Methods We developed a second-generation prototype microscope-integrated iOCT system that interfaces directly with a standard ophthalmic surgical microscope. Novel features for improved design and functionality included improved profile and ergonomics, as well as a tunable lens system for optimized image quality and heads-up display (HUD) system for surgeon feedback. Novel material testing was performed for potential suitability for OCT-compatible instrumentation based on light scattering and transmission characteristics. Prototype surgical instruments were developed based on material testing and tested using the microscope-integrated iOCT system. Several surgical maneuvers were performed and imaged, and surgical motion visualization was evaluated with a unique scanning and image processing protocol. Results High-resolution images were successfully obtained with the microscope-integrated iOCT system with HUD feedback. Six semi-transparent materials were characterized to determine their attenuation coefficients and scatter density with an 830 nm OCT light source. Based on these optical properties, polycarbonate was selected as a material substrate for prototype instrument construction. A surgical pick, retinal forceps, and corneal needle were constructed with semi-transparent materials. Excellent visualization of both the underlying tissues and surgical instrument were achieved on OCT cross-section. Using model eyes, various surgical maneuvers were visualized, including membrane peeling, vessel manipulation, cannulation of the subretinal space, subretinal intraocular foreign body removal, and corneal penetration. Conclusions Significant iterative improvements in integrative technology related to iOCT and ophthalmic surgery are demonstrated. PMID:25141340

Structural Investigation of Biological and Semiconductor Nanostructures with Nonlinear Multicontrast Microscopy

NASA Astrophysics Data System (ADS)

Cisek, Richard

Physical and functional properties of advanced nano-composite materials and biological structures are determined by self-organized atoms and molecules into nanostructures and in turn by microscopic organization of the nanostructures into assemblies of higher structural complexity. Therefore, microscopes are indispensable tools for structural investigations at various levels of organization. In this work, novel nonlinear optical microscopy methods were developed to non-invasively study structural organization at the nanoscopic and microscopic levels. Atomic organization of semiconductor nanowires, molecular organization of amylose biocrystallites in starch granules, and microscopic organization of several photosynthetic organisms was elucidated. The structure of ZnSe nanowires, key components in many modern nanodevices, was investigated using polarization harmonic generation microscopy. Based on nonlinear optical properties of the different crystal lattices, zinc blende and wurtzite nanowires were differentiated, and the three-dimensional orientation of the zinc blende nanowires could be found. The structure of starch granules, a model biocrystal, important in food as well as health sciences, was also investigated using polarization harmonic microscopy. The study was combined with ab initio calculations using the crystal structures of amylose A and B, revealing that second harmonic signals originate from the hydroxide and hydrogen bonds in the starch granules. Visualization of several photosynthetic organisms including the green algae, Chlamydomonas reinhardtii, two species of cyanobacteria, Leptolyngbya sp. and Anabaena sp., aggregates of light-harvesting pigment-protein complexes as well as chloroplasts from green plants were also explored, revealing that future nonlinear microscopy applications could include structural studies of cell walls, the Chlamydomonas eyespot, and photosynthetic membranes. In this study, several nonlinear optical microscopy modalities were developed for quantitative structural investigations of nano and micro-sized architectures. Non-invasive extraction of crystallographic information in microscopic samples will have a number of potential benefits, for example, in clinical applications, allowing observations of disease states inside tissues without the need for biopsy. Industrial nanotechnology will benefit from fast determination of nanostructures with nonlinear microscopy that will improve quality of nanodevices.

In vivo imaging of middle-ear and inner-ear microstructures of a mouse guided by SD-OCT combined with a surgical microscope

PubMed Central

Cho, Nam Hyun; Jang, Jeong Hun; Jung, Woonggyu; Kim, Jeehyun

2014-01-01

We developed an augmented-reality system that combines optical coherence tomography (OCT) with a surgical microscope. By sharing the common optical path in the microscope and OCT, we could simultaneously acquire OCT and microscope views. The system was tested to identify the middle-ear and inner-ear microstructures of a mouse. Considering the probability of clinical application including otorhinolaryngology, diseases such as middle-ear effusion were visualized using in vivo mouse and OCT images simultaneously acquired through the eyepiece of the surgical microscope during surgical manipulation using the proposed system. This system is expected to realize a new practical area of OCT application. PMID:24787787

Optical micromanipulation methods for controlled rotation, transportation, and microinjection of biological objects.

PubMed

Mohanty, S K; Gupta, P K

2007-01-01

The use of laser microtools for rotation and controlled transport of microscopic biological objects and for microinjection of exogenous material in cells is discussed. We first provide a brief overview of the laser tweezers-based methods for rotation or orientation of microscopic objects. Particular emphasis is placed on the methods that are more suitable for the manipulation of biological objects, and the use of these for two-dimensional (2D) and 3D rotations/orientations of intracellular objects is discussed. We also discuss how a change in the shape of a red blood cell (RBC) suspended in hypertonic buffer leads to its rotation when it is optically tweezed. The potential use of this approach for the diagnosis of malaria is also illustrated. The use of a line tweezers having an asymmetric intensity distribution about the center of its major axis for simultaneous transport of microscopic objects, and the successful use of this approach for induction, enhancement, and guidance of neuronal growth cones is presented next. Finally, we describe laser microbeam-assisted microinjection of impermeable drugs into cells and also briefly discuss possible adverse effects of the laser trap or microbeams on cells.

(Gene sequencing by scanning molecular exciton microscopy)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-01-01

This report details progress made in setting up a laboratory for optical microscopy of genes. The apparatus including a fluorescence microscope, a scanning optical microscope, various spectrometers, and supporting computers is described. Results in developing photon and exciton tips, and in preparing samples are presented. (GHH)

Design, assembly, and optical bench testing of a high-numerical-aperture miniature injection-molded objective for fiber-optic confocal reflectance microscopy.

PubMed

Chidley, Matthew D; Carlson, Kristen D; Richards-Kortum, Rebecca R; Descour, Michael R

2006-04-10

The design, analysis, assembly methods, and optical-bench test results for a miniature injection-molded plastic objective lens used in a fiber-optic confocal reflectance microscope are presented. The five-lens plastic objective was tested as a stand-alone optical system before its integration into a confocal microscope for in vivo imaging of cells and tissue. Changing the spacing and rotation of the individual optical elements can compensate for fabrication inaccuracies and improve performance. The system performance of the miniature objective lens is measured by use of an industry-accepted slanted-edge modulation transfer function (MTF) metric. An estimated Strehl ratio of 0.61 and a MTF value of 0.66 at the fiber-optic bundle Nyquist frequency have been obtained. The optical bench testing system is configured to permit interactive optical alignment during testing to optimize performance. These results are part of an effort to demonstrate the manufacturability of low-cost, high-performance biomedical optics for high-resolution in vivo imaging. Disposable endoscopic microscope objectives could help in vivo confocal microscopy technology mature to permit wide-scale clinical screening and detection of early cancers and precancerous lesions.

Atmospheric scanning electron microscope for correlative microscopy.

PubMed

Morrison, Ian E G; Dennison, Clare L; Nishiyama, Hidetoshi; Suga, Mitsuo; Sato, Chikara; Yarwood, Andrew; O'Toole, Peter J

2012-01-01

The JEOL ClairScope is the first truly correlative scanning electron and optical microscope. An inverted scanning electron microscope (SEM) column allows electron images of wet samples to be obtained in ambient conditions in a biological culture dish, via a silicon nitride film window in the base. A standard inverted optical microscope positioned above the dish holder can be used to take reflected light and epifluorescence images of the same sample, under atmospheric conditions that permit biochemical modifications. For SEM, the open dish allows successive staining operations to be performed without moving the holder. The standard optical color camera used for fluorescence imaging can be exchanged for a high-sensitivity monochrome camera to detect low-intensity fluorescence signals, and also cathodoluminescence emission from nanophosphor particles. If these particles are applied to the sample at a suitable density, they can greatly assist the task of perfecting the correlation between the optical and electron images. Copyright © 2012 Elsevier Inc. All rights reserved.

Wide spectral range confocal microscope based on endlessly single-mode fiber.

PubMed

Hubbard, R; Ovchinnikov, Yu B; Hayes, J; Richardson, D J; Fu, Y J; Lin, S D; See, P; Sinclair, A G

2010-08-30

We report an endlessly single mode, fiber-optic confocal microscope, based on a large mode area photonic crystal fiber. The microscope confines a very broad spectral range of excitation and emission wavelengths to a single spatial mode in the fiber. Single-mode operation over an optical octave is feasible. At a magnification of 10 and λ = 900 nm, its resolution was measured to be 1.0 μm (lateral) and 2.5 μm (axial). The microscope's use is demonstrated by imaging single photons emitted by individual InAs quantum dots in a pillar microcavity.

Generation-3 programmable array microscope (PAM) with digital micro-mirror device (DMD)

NASA Astrophysics Data System (ADS)

De Beule, Pieter A. A.; de Vries, Anthony H. B.; Arndt-Jovin, Donna J.; Jovin, Thomas M.

2011-03-01

We report progress on the construction of an optical sectioning programmable array microscope (PAM) implemented with a digital micro-mirror device (DMD) spatial light modulator (SLM) utilized for both fluorescence illumination and detection. The introduction of binary intensity modulation at the focal plane of a microscope objective in a computer controlled pixilated mode allows the recovery of an optically sectioned image. Illumination patterns can be changed very quickly, in contrast to static Nipkow disk or aperture correlation implementations, thereby creating an optical system that can be optimized to the optical specimen in a convenient manner, e.g. for patterned photobleaching, photobleaching reduction, or spatial superresolution. We present a third generation (Gen-3) dual path PAM module incorporating the 25 kHz binary frame rate TI 1080p DMD and a newly developed optical system that offers diffraction limited imaging with compensation of tilt angle distortion.

Nanoscale Optical Imaging and Spectroscopy from Visible to Mid-Infrared

DTIC Science & Technology

2015-11-13

field characterization of nanoscale materials, it also complements the near- field scanning optical microscope currently available in the PI’s lab...field scanning optical microscope currently available in the PI’s lab. This equipment will begin making major impacts on at least three current DoD...SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6

Microscopic Engine Powered by Critical Demixing

NASA Astrophysics Data System (ADS)

Schmidt, Falko; Magazzù, Alessandro; Callegari, Agnese; Biancofiore, Luca; Cichos, Frank; Volpe, Giovanni

2018-02-01

We experimentally demonstrate a microscopic engine powered by the local reversible demixing of a critical mixture. We show that, when an absorbing microsphere is optically trapped by a focused laser beam in a subcritical mixture, it is set into rotation around the optical axis of the beam because of the emergence of diffusiophoretic propulsion. This behavior can be controlled by adjusting the optical power, the temperature, and the criticality of the mixture.

Tapered fiber optical tweezers for microscopic particle trapping: fabrication and application

NASA Astrophysics Data System (ADS)

Liu, Zhihai; Guo, Chengkai; Yang, Jun; Yuan, Libo

2006-12-01

A novel single tapered fiber optical tweezers is proposed and fabricated by heating and drawing technology. The microscopic particle tapping performance of this special designed tapered fiber probe is demonstrated and investigated. The distribution of the optical field emerging from the tapered fiber tip is numerically calculated based on the beam propagation method. The trapping force FDTD analysis results, both axial and transverse, are also given.

Subwavelenght Light Localization in Nanostructured Surfaces

NASA Astrophysics Data System (ADS)

Coello, V.; Wang, S.; Siqueiros, J.; Bozhevolnyi, S. I.

Using a photon scanning tunneling microscope, we studied near field optical images obtained with a surface plasmon polariton (SPP) being resonantly excited along a surface with a random introduced roughness. The SPP intensity field distributions showed an optical enhancement in the form of round bright spots up to 5 times larger than the background signal. We also show an artificially fabricated SPP curved micromirror along with the corresponding near-field optical image. The recorded optical signal exhibited an enhancement up to 10 times larger than the background, which has been generated for the first time in a controlled form. A numerical simulation of a parabolic micromirror based on isotropic pointlike scatterers is analyzed and compared with experimental results. The potential of creating microstructures able to control SPP optical field enhancement is showed in a novel numerically simulated microcavity for SPP's.

Acousto-Optic Tunable Filter Hyperspectral Microscope Imaging Method for Characterizing Spectra from Foodborne Pathogens.

USDA-ARS?s Scientific Manuscript database

Hyperspectral microscope imaging (HMI) method, which provides both spatial and spectral characteristics of samples, can be effective for foodborne pathogen detection. The acousto-optic tunable filter (AOTF)-based HMI method can be used to characterize spectral properties of biofilms formed by Salmon...

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.

Zoom microscope objective using electrowetting lenses.

PubMed

Li, Lei; Wang, Di; Liu, Chao; Wang, Qiong-Hua

2016-02-08

We report a zoom microscope objective which can achieve continuous zoom change and correct the aberrations dynamically. The objective consists of three electrowetting liquid lenses and two glass lenses. The magnification is changed by applying voltages on the three electrowetting lenses. Besides, the three electrowetting liquid lenses can play a role to correct the aberrations. A digital microscope based on the proposed objective is demonstrated. We analyzed the properties of the proposed objective. In contrast to the conventional objectives, the proposed objective can be tuned from ~7.8 × to ~13.2 × continuously. For our objective, the working distance is fixed, which means no movement parts are needed to refocus or change its magnification. Moreover, the zoom objective can be dynamically optimized for a wide range of wavelength. Using such an objective, the fabrication tolerance of the optical system is larger than that of a conventional system, which can decrease the fabrication cost. The proposed zoom microscope objective cannot only take place of the conventional objective, but also has potential application in the 3D microscopy.

A pragmatic guide to multiphoton microscope design

PubMed Central

Young, Michael D.; Field, Jeffrey J.; Sheetz, Kraig E.; Bartels, Randy A.; Squier, Jeff

2016-01-01

Multiphoton microscopy has emerged as a ubiquitous tool for studying microscopic structure and function across a broad range of disciplines. As such, the intent of this paper is to present a comprehensive resource for the construction and performance evaluation of a multiphoton microscope that will be understandable to the broad range of scientific fields that presently exploit, or wish to begin exploiting, this powerful technology. With this in mind, we have developed a guide to aid in the design of a multiphoton microscope. We discuss source selection, optical management of dispersion, image-relay systems with scan optics, objective-lens selection, single-element light-collection theory, photon-counting detection, image rendering, and finally, an illustrated guide for building an example microscope. PMID:27182429

Design of a normal incidence multilayer imaging x-ray microscope.

PubMed

Shealy, D L; Gabardi, D R; Hoover, R B; Walker, A B; Lindblom, J F; Barbee, T W

1989-01-01

Normal incidence multilayer Cassegrain x-ray telescopes were flown on the Stanford/MSFC Rocket X-Ray Spectroheliograph. These instruments produced high spatial resolution images of the Sun and conclusively demonstrated that doubly reflecting multilayer x-ray optical systems are feasible. The images indicated that aplanatic imaging soft x-ray /EUV microscopes should be achievable using multilayer optics technology. We have designed a doubly reflecting normal incidence multilayer imaging x-ray microscope based on the Schwarzschild configuration. The Schwarzschild microscope utilizes two spherical mirrors with concentric radii of curvature which are chosen such that the third-order spherical aberration and coma are minimized. We discuss the design of the microscope and the results of the optical system ray trace analysis which indicates that diffraction-limited performance with 600 Å spatial resolution should be obtainable over a 1 mm field of view at a wavelength of 100 Å. Fabrication of several imaging soft x-ray microscopes based upon these designs, for use in conjunction with x-ray telescopes and laser fusion research, is now in progress. High resolution aplanatic imaging x-ray microscopes using normal incidence multilayer x-ray mirrors should have many important applications in advanced x-ray astronomical instrumentation, x-ray lithography, biological, biomedical, metallurgical, and laser fusion research.

Double-clad photonic crystal fiber coupler for compact nonlinear optical microscopy imaging.

PubMed

Fu, Ling; Gu, Min

2006-05-15

A 1 x 2 double-clad photonic crystal fiber coupler is fabricated by the fused tapered method, showing a low excess loss of 1.1 dB and a splitting ratio of 97/3 over the entire visible and near-infrared wavelength range. In addition to the property of splitting the laser power, the double-clad feature of the coupler facilitates the separation of a near-infrared single-mode beam from a visible multimode beam, which is ideal for nonlinear optical microscopy imaging. In conjunction with a gradient-index lens, this coupler is used to construct a miniaturized microscope based on two-photon fluorescence and second-harmonic generation. Three-dimensional nonlinear optical images demonstrate potential applications of the coupler to compact all-fiber and nonlinear optical microscopy and endoscopy.

Augmented microscopy with near-infrared fluorescence detection

NASA Astrophysics Data System (ADS)

Watson, Jeffrey R.; Martirosyan, Nikolay; Skoch, Jesse; Lemole, G. Michael; Anton, Rein; Romanowski, Marek

2015-03-01

Near-infrared (NIR) fluorescence has become a frequently used intraoperative technique for image-guided surgical interventions. In procedures such as cerebral angiography, surgeons use the optical surgical microscope for the color view of the surgical field, and then switch to an electronic display for the NIR fluorescence images. However, the lack of stereoscopic, real-time, and on-site coregistration adds time and uncertainty to image-guided surgical procedures. To address these limitations, we developed the augmented microscope, whereby the electronically processed NIR fluorescence image is overlaid with the anatomical optical image in real-time within the optical path of the microscope. In vitro, the augmented microscope can detect and display indocyanine green (ICG) concentrations down to 94.5 nM, overlaid with the anatomical color image. We prepared polyacrylamide tissue phantoms with embedded polystyrene beads, yielding scattering properties similar to brain matter. In this model, 194 μM solution of ICG was detectable up to depths of 5 mm. ICG angiography was then performed in anesthetized rats. A dynamic process of ICG distribution in the vascular system overlaid with anatomical color images was observed and recorded. In summary, the augmented microscope demonstrates NIR fluorescence detection with superior real-time coregistration displayed within the ocular of the stereomicroscope. In comparison to other techniques, the augmented microscope retains full stereoscopic vision and optical controls including magnification and focus, camera capture, and multiuser access. Augmented microscopy may find application in surgeries where the use of traditional microscopes can be enhanced by contrast agents and image guided delivery of therapeutics, including oncology, neurosurgery, and ophthalmology.

Microscope basics.

PubMed

Sluder, Greenfield; Nordberg, Joshua J

2013-01-01

This chapter provides information on how microscopes work and discusses some of the microscope issues to be considered in using a video camera on the microscope. There are two types of microscopes in use today for research in cell biology-the older finite tube-length (typically 160mm mechanical tube length) microscopes and the infinity optics microscopes that are now produced. The objective lens forms a magnified, real image of the specimen at a specific distance from the objective known as the intermediate image plane. All objectives are designed to be used with the specimen at a defined distance from the front lens element of the objective (the working distance) so that the image formed is located at a specific location in the microscope. Infinity optics microscopes differ from the finite tube-length microscopes in that the objectives are designed to project the image of the specimen to infinity and do not, on their own, form a real image of the specimen. Three types of objectives are in common use today-plan achromats, plan apochromats, and plan fluorite lenses. The concept of mounting video cameras on the microscope is also presented in the chapter. Copyright © 2003 Elsevier Inc. All rights reserved.

Diamond Quantum Nanoemitters: Cross Discipline Research on Hyperbolic Optical Systems for Control of Quantum Nanoemitters

DTIC Science & Technology

2017-05-05

results of this project there are: (1) the investigation of the effect of phonons on the optical properties of solid state emitters. A microscopic ...In  what  follows  we  list  the  main  results  and  undergoing  research.   2. Results 2.1   Microscopic  modeling...fluorescent  markers   for   biological   measurements.   Here,   we   present   a   first-­‐principles   microscopic   description

Design and construction of a modular low-cost epifluorescence upright microscope for neuron visualized recording and fluorescence detection.

PubMed

Beltran-Parrazal, Luis; Morgado-Valle, Consuelo; Serrano, Raul E; Manzo, Jorge; Vergara, Julio L

2014-03-30

One of the limitations when establishing an electrophysiology setup, particularly in low resource settings, is the high cost of microscopes. The average cost for a microscope equipped with the optics for infrared (IR) contrast or microfluorometry is $40,000. We hypothesized that optical elements and features included in commercial microscopes are not necessary to IR video-visualize neurons or for microfluorometry. We present instructions for building a low-cost epifluorescence upright microscope suitable for visualized patch-clamp recording and fluorescence detection using mostly catalog-available parts. This microscope supports applications such as visualized whole-cell recording using IR oblique illumination (IR-OI), or more complex applications such as microfluorometry using a photodiode. In both IR-OI and fluorescence, actual resolution measured with 2-μm latex beads is close to theoretical resolution. The lack of movable parts to switch configurations ensures stability when doing intracellular recording. The low cost is a significant advantage of this microscope compared to existent custom-built microscopes. The cost of the simplest configuration with IR-OI is ∼$2000, whereas the cost of the configuration with epifluorescence is ∼$5000. Since this design does not use pieces discarded from commercial microscopes, it is completely reproducible. We suggest that this microscope is a viable alternative for doing in vitro electrophysiology and microfluorometry in low-resource settings. Characteristics such as an open box design, easy assembly, and low-cost make this microscope a useful instrument for science education and teaching for topics such as optics, biology, neuroscience, and for scientific "hands-on" workshops. Copyright © 2014 Elsevier B.V. All rights reserved.

Apertureless near-field scanning optical microscope working with or without laser source.

PubMed

Formanek, F; De Wilde, Y; Aigouy, L; Chen, Y

2004-01-01

An apertureless near-field scanning optical microscope (ANSOM), used indifferent configurations, is presented. Our versatile home-made setup, based on a sharp tungsten tip glued onto a quartz tuning fork and working in tapping mode, allows to perform imaging over a broad spectral range. We have recorded optical images in the visible (wavelength, lambda = 655 nm) and in the infrared (lambda = 10.6 microm), proving that the setup routinely achieves an optical resolution of <50 nm regardless of the illumination wavelength. We have also shown optical images recorded in the visible (lambda = 655 nm) in an inverted configuration where the tip does not perturb the focused spot of the illumination laser. Approach curves as well as image profiles have revealed that on demodulating the optical signal at higher harmonics, we can obtain an effective probe sharpening which results in an improvement of the resolution. Finally, we have presented optical images recorded in the infrared without any illumination, that is, the usual laser source is replaced by a simple heating of the sample. This has shown that the ANSOM can be used as a near-field thermal optical microscope (NTOM) to probe the near field generated by the thermal emission of the sample.

Multiplexed neural recording along a single optical fiber via optical reflectometry

PubMed Central

Rodriques, Samuel G.; Marblestone, Adam H.; Scholvin, Jorg; Dapello, Joel; Sarkar, Deblina; Mankin, Max; Gao, Ruixuan; Wood, Lowell; Boyden, Edward S.

2016-01-01

Abstract. We introduce the design and theoretical analysis of a fiber-optic architecture for neural recording without contrast agents, which transduces neural electrical signals into a multiplexed optical readout. Our sensor design is inspired by electro-optic modulators, which modulate the refractive index of a waveguide by applying a voltage across an electro-optic core material. We estimate that this design would allow recording of the activities of individual neurons located at points along a 10-cm length of optical fiber with 40-μm axial resolution and sensitivity down to 100  μV using commercially available optical reflectometers as readout devices. Neural recording sites detect a potential difference against a reference and apply this potential to a capacitor. The waveguide serves as one of the plates of the capacitor, so charge accumulation across the capacitor results in an optical effect. A key concept of the design is that the sensitivity can be improved by increasing the capacitance. To maximize the capacitance, we utilize a microscopic layer of material with high relative permittivity. If suitable materials can be found—possessing high capacitance per unit area as well as favorable properties with respect to toxicity, optical attenuation, ohmic junctions, and surface capacitance—then such sensing fibers could, in principle, be scaled down to few-micron cross-sections for minimally invasive neural interfacing. We study these material requirements and propose potential material choices. Custom-designed multimaterial optical fibers, probed using a reflectometric readout, may, therefore, provide a powerful platform for neural sensing. PMID:27194640

Modified Linnik microscopic interferometry for quantitative depth evaluation of diffraction-limited microgroove

NASA Astrophysics Data System (ADS)

Ye, Shiwei; Takahashi, Satoru; Michihata, Masaki; Takamasu, Kiyoshi

2018-05-01

The quality control of microgrooves is extremely crucial to ensure the performance and stability of microstructures and improve their fabrication efficiency. This paper introduces a novel optical inspection method and a modified Linnik microscopic interferometer measurement system to detect the depth of microgrooves with a width less than the diffraction limit. Using this optical method, the depth of diffraction-limited microgrooves can be related to the near-field optical phase difference, which cannot be practically observed but can be computed from practical far-field observations. Thus, a modified Linnik microscopic interferometer system based on three identical objective lenses and an optical path reversibility principle were developed. In addition, experiments for standard grating microgrooves on the silicon surface were carried out to demonstrate the feasibility and repeatability of the proposed method and developed measurement system.

[Gene sequencing by scanning molecular exciton microscopy]. Progress report, October 1, 1990--September 30, 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-12-31

This report details progress made in setting up a laboratory for optical microscopy of genes. The apparatus including a fluorescence microscope, a scanning optical microscope, various spectrometers, and supporting computers is described. Results in developing photon and exciton tips, and in preparing samples are presented. (GHH)

Measurement of specimen-induced aberrations of biological samples using phase stepping interferometry.

PubMed

Schwertner, M; Booth, M J; Neil, M A A; Wilson, T

2004-01-01

Confocal or multiphoton microscopes, which deliver optical sections and three-dimensional (3D) images of thick specimens, are widely used in biology. These techniques, however, are sensitive to aberrations that may originate from the refractive index structure of the specimen itself. The aberrations cause reduced signal intensity and the 3D resolution of the instrument is compromised. It has been suggested to correct for aberrations in confocal microscopes using adaptive optics. In order to define the design specifications for such adaptive optics systems, one has to know the amount of aberrations present for typical applications such as with biological samples. We have built a phase stepping interferometer microscope that directly measures the aberration of the wavefront. The modal content of the wavefront is extracted by employing Zernike mode decomposition. Results for typical biological specimens are presented. It was found for all samples investigated that higher order Zernike modes give only a small contribution to the overall aberration. Therefore, these higher order modes can be neglected in future adaptive optics sensing and correction schemes implemented into confocal or multiphoton microscopes, leading to more efficient designs.

Highly sensitive mode mapping of whispering-gallery modes by scanning thermocouple-probe microscopy.

PubMed

Klein, Angela E; Schmidt, Carsten; Liebsch, Mattes; Janunts, Norik; Dobynde, Mikhail; Tünnermann, Andreas; Pertsch, Thomas

2014-03-01

We propose a method for mapping optical near-fields with the help of a thermocouple scanning-probe microscope tip. As the tip scans the sample surface, its apex is heated by light absorption, generating a thermovoltage. The thermovoltage map represents the intensity distribution of light at the sample surface. The measurement technique has been employed to map optical whispering-gallery modes in fused silica microdisk resonators operating at near-infrared wavelengths. The method could potentially be employed for near-field imaging of a variety of systems in the near-infrared and visible spectral range.

Crystal Structure, Magnetic and Optical Properties of Mn-Doped BiFeO₃ by Hydrothermal Synthesis.

PubMed

Zhang, Ning; Wei, Qinhua; Qin, Laishun; Chen, Da; Chen, Zhi; Niu, Feng; Wang, Jiangying; Huanag, Yuexiang

2017-01-01

In this paper, Mn doped BiFeO₃ were firstly synthesized by hydrothermal process. The influence of Mn doping on structural, optical and magnetic properties of BiFeO₃ was studied. The different amounts of Mn doping in BiFeO₃ were characterized by X-ray diffraction, Scanning Electron Microscope, Energy Dispersive X-ray Spectroscope, UV-Vis diffuse reflectance spectroscopy and magnetic measurements. The X-ray diffraction (XRD) patterns confirmed the formation of pure phase rhombohedral structure in BiFe(1−x) Mn (x) O₃ (x = 0.01, 0.03, 0.05, 0.07) samples. The morphologies and chemical compositions of as-prepared samples could be observed by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscope (EDS). A relative large saturated magnetization (Ms) of 0.53 emu/g for x = 0.07 sample was obtained at room temperature, which is considered to be Mn ions doping. UV-Vis diffuse reflectance spectroscopy showed strong absorption of light in the range of 200–1000 nm, indicating the optical band gap in the visible region for these samples. This implied that BiFe(1−x) Mn(x)O₃ may be a potential photocatalyst for utilizing solar energy.

VISUALIZATION FROM INTRAOPERATIVE SWEPT-SOURCE MICROSCOPE-INTEGRATED OPTICAL COHERENCE TOMOGRAPHY IN VITRECTOMY FOR COMPLICATIONS OF PROLIFERATIVE DIABETIC RETINOPATHY.

PubMed

Gabr, Hesham; Chen, Xi; Zevallos-Carrasco, Oscar M; Viehland, Christian; Dandrige, Alexandria; Sarin, Neeru; Mahmoud, Tamer H; Vajzovic, Lejla; Izatt, Joseph A; Toth, Cynthia A

2018-01-10

To evaluate the use of live volumetric (4D) intraoperative swept-source microscope-integrated optical coherence tomography in vitrectomy for proliferative diabetic retinopathy complications. In this prospective study, we analyzed a subgroup of patients with proliferative diabetic retinopathy complications who required vitrectomy and who were imaged by the research swept-source microscope-integrated optical coherence tomography system. In near real time, images were displayed in stereo heads-up display facilitating intraoperative surgeon feedback. Postoperative review included scoring image quality, identifying different diabetic retinopathy-associated pathologies and reviewing the intraoperatively documented surgeon feedback. Twenty eyes were included. Indications for vitrectomy were tractional retinal detachment (16 eyes), combined tractional-rhegmatogenous retinal detachment (2 eyes), and vitreous hemorrhage (2 eyes). Useful, good-quality 2D (B-scans) and 4D images were obtained in 16/20 eyes (80%). In these eyes, multiple diabetic retinopathy complications could be imaged. Swept-source microscope-integrated optical coherence tomography provided surgical guidance, e.g., in identifying dissection planes under fibrovascular membranes, and in determining residual membranes and traction that would benefit from additional peeling. In 4/20 eyes (20%), acceptable images were captured, but they were not useful due to high tractional retinal detachment elevation which was challenging for imaging. Swept-source microscope-integrated optical coherence tomography can provide important guidance during surgery for proliferative diabetic retinopathy complications through intraoperative identification of different complications and facilitation of intraoperative decision making.

EnLightenment: High resolution smartphone microscopy as an educational and public engagement platform.

PubMed

Wicks, Laura C; Cairns, Gemma S; Melnyk, Jacob; Bryce, Scott; Duncan, Rory R; Dalgarno, Paul A

2017-01-01

We developed a simple, cost-effective smartphone microscopy platform for use in educational and public engagement programs. We demonstrated its effectiveness, and potential for citizen science through a national imaging initiative, EnLightenment . The cost effectiveness of the instrument allowed for the program to deliver over 500 microscopes to more than 100 secondary schools throughout Scotland, targeting 1000's of 12-14 year olds. Through careful, quantified, selection of a high power, low-cost objective lens, our smartphone microscope has an imaging resolution of microns, with a working distance of 3 mm. It is therefore capable of imaging single cells and sub-cellular features, and retains usability for young children. The microscopes were designed in kit form and provided an interdisciplinary educational tool. By providing full lesson plans and support material, we developed a framework to explore optical design, microscope performance, engineering challenges on construction and real-world applications in life sciences, biological imaging, marine biology, art, and technology. A national online imaging competition framed EnLightenment ; with over 500 high quality images submitted of diverse content, spanning multiple disciplines. With examples of cellular and sub-cellular features clearly identifiable in some submissions, we show how young public can use these instruments for research-level imaging applications, and the potential of the instrument for citizen science programs.

EDITORIAL: Recent developments in biomedical optics

NASA Astrophysics Data System (ADS)

Wang, Ruikang K.; Hebden, Jeremy C.; Tuchin, Valery V.

2004-04-01

The rapid growth in laser and photonic technology has resulted in new tools being proposed and developed for use in the medical and biological sciences. Specifically, a discipline known as biomedical optics has emerged which is providing a broad variety of optical techniques and instruments for diagnostic, therapeutic and basic science applications. New laser sources, detectors and measurement techniques are yielding powerful new methods for the study of diseases on all scales, from single molecules, to specific tissues and whole organs. For example, novel laser microscopes permit spectroscopic and force measurements to be performed on single protein molecules; new optical devices provide information on molecular dynamics and structure to perform `optical biopsy' non-invasively and almost instantaneously; and optical coherence tomography and diffuse optical tomography allow visualization of specific tissues and organs. Using genetic promoters to derive luciferase expression, bioluminescence methods can generate molecular light switches, which serve as functional indicator lights reporting cellular conditions and responses in living animals. This technique could allow rapid assessment of and response to the effects of anti-tumour drugs, antibiotics, or antiviral drugs. This issue of Physics in Medicine and Biology highlights recent research in biomedical optics, and is based on invited contributions to the International Conference on Advanced Laser Technology (Focused on Biomedical Optics) held at Cranfield University at Silsoe on 19--23 September 2003. This meeting included sessions devoted to: diffuse optical imaging and spectroscopy; optical coherence tomography and coherent domain techniques; optical sensing and applications in life science; microscopic, spectroscopic and opto-acoustic imaging; therapeutic and diagnostic applications; and laser interaction with organic and inorganic materials. Twenty-one papers are included in this special issue. The first paper gives an overview on the current status of scanning laser ophthalmoscopy and its role in bioscience and medicine, while the second paper describes the current problems in tissue engineering and the potential role for optical coherence tomography. The following seven papers present and discuss latest developments in infrared spectroscopy and diffuse optical tomography for medical diagnostics. Eight further papers report recent advances in optical coherence tomography, covering new and evolving methods and instrumentation, theoretical and numerical modelling, and its clinical applications. The remaining papers cover miscellaneous topics in biomedical optics, including new developments in opto-acoustic imaging techniques, laser speckle imaging of blood flow in microcirculations, and potential of hollow-core photonic-crystal fibres for laser dentistry. We thank all the authors for their valuable contributions and their prompt responses to reviewers' comments. We are also very grateful to the reviewers for their hard work and their considerable efforts to meet tight deadlines.

Novel microscope-integrated stereoscopic heads-up display for intrasurgical optical coherence tomography

PubMed Central

Shen, Liangbo; Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Waterman, Gar; Hahn, Paul S.; Kuo, Anthony N.; Toth, Cynthia A.; Izatt, Joseph A.

2016-01-01

Intra-operative optical coherence tomography (OCT) requires a display technology which allows surgeons to visualize OCT data without disrupting surgery. Previous research and commercial intrasurgical OCT systems have integrated heads-up display (HUD) systems into surgical microscopes to provide monoscopic viewing of OCT data through one microscope ocular. To take full advantage of our previously reported real-time volumetric microscope-integrated OCT (4D MIOCT) system, we describe a stereoscopic HUD which projects a stereo pair of OCT volume renderings into both oculars simultaneously. The stereoscopic HUD uses a novel optical design employing spatial multiplexing to project dual OCT volume renderings utilizing a single micro-display. The optical performance of the surgical microscope with the HUD was quantitatively characterized and the addition of the HUD was found not to substantially effect the resolution, field of view, or pincushion distortion of the operating microscope. In a pilot depth perception subject study, five ophthalmic surgeons completed a pre-set dexterity task with 50.0% (SD = 37.3%) higher success rate and in 35.0% (SD = 24.8%) less time on average with stereoscopic OCT vision compared to monoscopic OCT vision. Preliminary experience using the HUD in 40 vitreo-retinal human surgeries by five ophthalmic surgeons is reported, in which all surgeons reported that the HUD did not alter their normal view of surgery and that live surgical maneuvers were readily visible in displayed stereoscopic OCT volumes. PMID:27231616

Development of HiLo Microscope and its use in In-Vivo Applications

NASA Astrophysics Data System (ADS)

Patel, Shreyas J.

The functionality of achieving optical sectioning in biomedical research is invaluable as it allows for visualization of a biological sample at different depths while being free of background scattering. Most current microscopy techniques that offer optical sectioning, unfortunately, require complex instrumentation and thus are generally costly. HiLo microscopy, on the other hand, offers the same functionality and advantage at a relatively low cost. Hence, the work described in this thesis involves the design, build, and application of a HiLo microscope. More specifically, a standalone HiLo microscope was built in addition to implementing HiLo microscopy on a standard fluorescence microscope. In HiLo microscopy, optical sectioning is achieved by acquiring two different types of images per focal plane. One image is acquired under uniform illumination and the other is acquired under speckle illumination. These images are processed using an algorithm that extracts in-focus information and removes features and glare that occur as a result of background fluorescence. To show the benefits of the HiLo microscopy, several imaging experiments on various samples were performed under a HiLo microscope and compared against a traditional fluorescence microscope and a confocal microscope, which is considered the gold standard in optical imaging. In-vitro and ex-vivo imaging was performed on a set of pollen grains, and optically cleared mouse brain and heart slices. Each of these experiments showed great reduction in background scattering at different depths under HiLo microscopy. More importantly, HiLo imaging of optically cleared heart slice demonstrated emergence of different vasculature at different depths. Reduction of out-of-focus light increased the spatial resolution and allowed better visualization of capillary vessels. Furthermore, HiLo imaging was tested in an in-vivo model of a rodent dorsal window chamber model. When imaging the same sample under confocal microscope, the results were comparable between the two modalities. Additionally, a method of achieving blood flow maps at different depth using a combination of HiLo and LSI imaging is also discussed. The significance of this combined technique could help categorize blood flow to particular depths; this can help improve outcomes of medical treatments such pulse dye laser and photodynamic therapy treatments.

Optical method for distance and displacement measurements of the probe-sample separation in a scanning near-field optical microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santamaria, L.; Siller, H. R.; Garcia-Ortiz, C. E., E-mail: cegarcia@cicese.mx

In this work, we present an alternative optical method to determine the probe-sample separation distance in a scanning near-field optical microscope. The experimental method is based in a Lloyd’s mirror interferometer and offers a measurement precision deviation of ∼100 nm using digital image processing and numerical analysis. The technique can also be strategically combined with the characterization of piezoelectric actuators and stability evaluation of the optical system. It also opens the possibility for the development of an automatic approximation control system valid for probe-sample distances from 5 to 500 μm.

Proper alignment of the microscope.

PubMed

Rottenfusser, Rudi

2013-01-01

The light microscope is merely the first element of an imaging system in a research facility. Such a system may include high-speed and/or high-resolution image acquisition capabilities, confocal technologies, and super-resolution methods of various types. Yet more than ever, the proverb "garbage in-garbage out" remains a fact. Image manipulations may be used to conceal a suboptimal microscope setup, but an artifact-free image can only be obtained when the microscope is optimally aligned, both mechanically and optically. Something else is often overlooked in the quest to get the best image out of the microscope: Proper sample preparation! The microscope optics can only do its job when its design criteria are matched to the specimen or vice versa. The specimen itself, the mounting medium, the cover slip, and the type of immersion medium (if applicable) are all part of the total optical makeup. To get the best results out of a microscope, understanding the functions of all of its variable components is important. Only then one knows how to optimize these components for the intended application. Different approaches might be chosen to discuss all of the microscope's components. We decided to follow the light path which starts with the light source and ends at the camera or the eyepieces. To add more transparency to this sequence, the section up to the microscope stage was called the "Illuminating Section", to be followed by the "Imaging Section" which starts with the microscope objective. After understanding the various components, we can start "working with the microscope." To get the best resolution and contrast from the microscope, the practice of "Koehler Illumination" should be understood and followed by every serious microscopist. Step-by-step instructions as well as illustrations of the beam path in an upright and inverted microscope are included in this chapter. A few practical considerations are listed in Section 3. Copyright © 2013 Elsevier Inc. All rights reserved.

Optical label-free and model-free probe of the surface potential of nanoscale and microscopic objects in aqueous solution

NASA Astrophysics Data System (ADS)

Lütgebaucks, Cornelis; Gonella, Grazia; Roke, Sylvie

2016-11-01

The electrostatic environment of aqueous systems is an essential ingredient for the function of any living system. To understand the electrostatic properties and their molecular foundation in soft, living, and three-dimensional systems, we developed a table-top model-free method to determine the surface potential of nano- and microscopic objects in aqueous solutions. Angle-resolved nonresonant second harmonic (SH) scattering measurements contain enough information to determine the surface potential unambiguously, without making assumptions on the structure of the interfacial region. The scattered SH light that is emitted from both the particle interface and the diffuse double layer can be detected in two different polarization states that have independent scattering patterns. The angular shape and intensity are determined by the surface potential and the second-order surface susceptibility. Calibrating the response with the SH intensity of bulk water, a single, unique surface potential value can be extracted. We demonstrate the method with 80 nm bare oil droplets in water and ˜50 nm dioleoylphosphatidylcholine (DOPC) and dioleoylphosphatidylserine (DOPS) liposomes at various ionic strengths.

MEMS-tunable dielectric metasurface lens.

PubMed

Arbabi, Ehsan; Arbabi, Amir; Kamali, Seyedeh Mahsa; Horie, Yu; Faraji-Dana, MohammadSadegh; Faraon, Andrei

2018-02-23

Varifocal lenses, conventionally implemented by changing the axial distance between multiple optical elements, have a wide range of applications in imaging and optical beam scanning. The use of conventional bulky refractive elements makes these varifocal lenses large, slow, and limits their tunability. Metasurfaces, a new category of lithographically defined diffractive devices, enable thin and lightweight optical elements with precisely engineered phase profiles. Here we demonstrate tunable metasurface doublets, based on microelectromechanical systems (MEMS), with more than 60 diopters (about 4%) change in the optical power upon a 1-μm movement of one metasurface, and a scanning frequency that can potentially reach a few kHz. They can also be integrated with a third metasurface to make compact microscopes (~1 mm thick) with a large corrected field of view (~500 μm or 40 degrees) and fast axial scanning for 3D imaging. This paves the way towards MEMS-integrated metasurfaces as a platform for tunable and reconfigurable optics.

Dielectric Optical-Controllable Magnifying Lens by Nonlinear Negative Refraction

PubMed Central

Cao, Jianjun; Shang, Ce; Zheng, Yuanlin; Feng, Yaming; Chen, Xianfeng; Liang, Xiaogan; Wan, Wenjie

2015-01-01

A simple optical lens plays an important role for exploring the microscopic world in science and technology by refracting light with tailored spatially varying refractive indices. Recent advancements in nanotechnology enable novel lenses, such as, superlens and hyperlens, with sub-wavelength resolution capabilities by specially designed materials’ refractive indices with meta-materials and transformation optics. However, these artificially nano- or micro-engineered lenses usually suffer high losses from metals and are highly demanding in fabrication. Here, we experimentally demonstrate, for the first time, a nonlinear dielectric magnifying lens using negative refraction by degenerate four-wave mixing in a plano-concave glass slide, obtaining magnified images. Moreover, we transform a nonlinear flat lens into a magnifying lens by introducing transformation optics into the nonlinear regime, achieving an all-optical controllable lensing effect through nonlinear wave mixing, which may have many potential applications in microscopy and imaging science. PMID:26149952

VizieR Online Data Catalog: Brussels nuclear reaction rate library (Aikawa+, 2005)

NASA Astrophysics Data System (ADS)

Aikawa, M.; Arnould, M.; Goriely, S.; Jorissen, A.; Takahashi, K.

2005-07-01

The present data is part of the Brussels nuclear reaction rate library (BRUSLIB) for astrophysics applications and concerns nuclear reaction rate predictions calculated within the statistical Hauser-Feshbach approximation and making use of global and coherent microscopic nuclear models for the quantities (nuclear masses, nuclear structure properties, nuclear level densities, gamma-ray strength functions, optical potentials) entering the rate calculations. (4 data files).

Variable Magnification With Kirkpatrick-Baez Optics for Synchrotron X-Ray Microscopy

PubMed Central

Jach, Terrence; Bakulin, Alex S.; Durbin, Stephen M.; Pedulla, Joseph; Macrander, Albert

2006-01-01

We describe the distinction between the operation of a short focal length x-ray microscope forming a real image with a laboratory source (convergent illumination) and with a highly collimated intense beam from a synchrotron light source (Köhler illumination). We demonstrate the distinction with a Kirkpatrick-Baez microscope consisting of short focal length multilayer mirrors operating at an energy of 8 keV. In addition to realizing improvements in the resolution of the optics, the synchrotron radiation microscope is not limited to the usual single magnification at a fixed image plane. Higher magnification images are produced by projection in the limit of geometrical optics with a collimated beam. However, in distinction to the common method of placing the sample behind the optical source of a diverging beam, we describe the situation in which the sample is located in the collimated beam before the optical element. The ultimate limits of this magnification result from diffraction by the specimen and are determined by the sample position relative to the focal point of the optic. We present criteria by which the diffraction is minimized. PMID:27274930

Enhancing performance of LCoS-SLM as adaptive optics by using computer-generated holograms modulation software

NASA Astrophysics Data System (ADS)

Tsai, Chun-Wei; Lyu, Bo-Han; Wang, Chen; Hung, Cheng-Chieh

2017-05-01

We have already developed multi-function and easy-to-use modulation software that was based on LabVIEW system. There are mainly four functions in this modulation software, such as computer generated holograms (CGH) generation, CGH reconstruction, image trimming, and special phase distribution. Based on the above development of CGH modulation software, we could enhance the performance of liquid crystal on silicon - spatial light modulator (LCoSSLM) as similar as the diffractive optical element (DOE) and use it on various adaptive optics (AO) applications. Through the development of special phase distribution, we are going to use the LCoS-SLM with CGH modulation software into AO technology, such as optical microscope system. When the LCOS-SLM panel is integrated in an optical microscope system, it could be placed on the illumination path or on the image forming path. However, LCOS-SLM provides a program-controllable liquid crystal array for optical microscope. It dynamically changes the amplitude or phase of light and gives the obvious advantage, "Flexibility", to the system

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

Sub-diffraction nano manipulation using STED AFM.

PubMed

Chacko, Jenu Varghese; Canale, Claudio; Harke, Benjamin; Diaspro, Alberto

2013-01-01

In the last two decades, nano manipulation has been recognized as a potential tool of scientific interest especially in nanotechnology and nano-robotics. Contemporary optical microscopy (super resolution) techniques have also reached the nanometer scale resolution to visualize this and hence a combination of super resolution aided nano manipulation ineluctably gives a new perspective to the scenario. Here we demonstrate how specificity and rapid determination of structures provided by stimulated emission depletion (STED) microscope can aid another microscopic tool with capability of mechanical manoeuvring, like an atomic force microscope (AFM) to get topological information or to target nano scaled materials. We also give proof of principle on how high-resolution real time visualization can improve nano manipulation capability within a dense sample, and how STED-AFM is an optimal combination for this job. With these evidences, this article points to future precise nano dissections and maybe even to a nano-snooker game with an AFM tip and fluorospheres.

Confocal fluorescence microscope with dual-axis architecture and biaxial postobjective scanning

PubMed Central

Wang, Thomas D.; Contag, Christopher H.; Mandella, Michael J.; Chan, Ning Y.; Kino, Gordon S.

2007-01-01

We present a novel confocal microscope that has dual-axis architecture and biaxial postobjective scanning for the collection of fluorescence images from biological specimens. This design uses two low-numerical-aperture lenses to achieve high axial resolution and long working distance, and the scanning mirror located distal to the lenses rotates along the orthogonal axes to produce arc-surface images over a large field of view (FOV). With fiber optic coupling, this microscope can potentially be scaled down to millimeter dimensions via microelectromechanical systems (MEMS) technology. We demonstrate a benchtop prototype with a spatial resolution ≤4.4 μm that collects fluorescence images with a high SNR and a good contrast ratio from specimens expressing GFP. Furthermore, the scanning mechanism produces only small differences in aberrations over the image FOV. These results demonstrate proof of concept of the dual-axis confocal architecture for in vivo molecular and cellular imaging. PMID:15250760

Using naturally occurring polysaccharides to align molecules with nonlinear optical activity

NASA Technical Reports Server (NTRS)

Prasthofer, Thomas

1996-01-01

The Biophysics and Advanced Materials Branch of the Microgravity Science and Applications Division at Marshall Space Flight Center has been investigating polymers with the potential for nonlinear optical (NLO) applications for a number of years. Some of the potential applications for NLO materials include optical communications, computing, and switching. To this point the branch's research has involved polydiacetylenes, phthalocyanins, and other synthetic polymers which have inherent NLO properties. The aim of the present research is to investigate the possibility of using naturally occurring polymers such as polysaccharides or proteins to trap and align small organic molecules with useful NLO properties. Ordering molecules with NLO properties enhances 3rd order nonlinear effects and is required for 2nd order nonlinear effects. Potential advantages of such a system are the flexibility to use different small molecules with varying chemical and optical properties, the stability and cost of the polymers, and the ability to form thin, optically transparent films. Since the quality of any polymer films depends on optimizing ordering and minimizing defects, this work is particularly well suited for microgravity experiments. Polysaccharide and protein polymers form microscopic crystallites which must align to form ordered arrays. The ordered association of crystallites is disrupted by gravity effects and NASA research on protein crystal growth has demonstrated that low gravity conditions can improve crystal quality.

Development and Optical Testing of the Camera, Hand Lens, and Microscope Probe with Scannable Laser Spectroscopy (CHAMP-SLS)

NASA Technical Reports Server (NTRS)

Mungas, Greg S.; Gursel, Yekta; Sepulveda, Cesar A.; Anderson, Mark; La Baw, Clayton; Johnson, Kenneth R.; Deans, Matthew; Beegle, Luther; Boynton, John

2008-01-01

Conducting high resolution field microscopy with coupled laser spectroscopy that can be used to selectively analyze the surface chemistry of individual pixels in a scene is an enabling capability for next generation robotic and manned spaceflight missions, civil, and military applications. In the laboratory, we use a range of imaging and surface preparation tools that provide us with in-focus images, context imaging for identifying features that we want to investigate at high magnification, and surface-optical coupling that allows us to apply optical spectroscopic analysis techniques for analyzing surface chemistry particularly at high magnifications. The camera, hand lens, and microscope probe with scannable laser spectroscopy (CHAMP-SLS) is an imaging/spectroscopy instrument capable of imaging continuously from infinity down to high resolution microscopy (resolution of approx. 1 micron/pixel in a final camera format), the closer CHAMP-SLS is placed to a feature, the higher the resultant magnification. At hand lens to microscopic magnifications, the imaged scene can be selectively interrogated with point spectroscopic techniques such as Raman spectroscopy, microscopic Laser Induced Breakdown Spectroscopy (micro-LIBS), laser ablation mass-spectrometry, Fluorescence spectroscopy, and/or Reflectance spectroscopy. This paper summarizes the optical design, development, and testing of the CHAMP-SLS optics.

Malaria Diagnosis Using a Mobile Phone Polarized Microscope

NASA Astrophysics Data System (ADS)

Pirnstill, Casey W.; Coté, Gerard L.

2015-08-01

Malaria remains a major global health burden, and new methods for low-cost, high-sensitivity, diagnosis are essential, particularly in remote areas with low-resource around the world. In this paper, a cost effective, optical cell-phone based transmission polarized light microscope system is presented for imaging the malaria pigment known as hemozoin. It can be difficult to determine the presence of the pigment from background and other artifacts, even for skilled microscopy technicians. The pigment is much easier to observe using polarized light microscopy. However, implementation of polarized light microscopy lacks widespread adoption because the existing commercial devices have complicated designs, require sophisticated maintenance, tend to be bulky, can be expensive, and would require re-training for existing microscopy technicians. To this end, a high fidelity and high optical resolution cell-phone based polarized light microscopy system is presented which is comparable to larger bench-top polarized microscopy systems but at much lower cost and complexity. The detection of malaria in fixed and stained blood smears is presented using both, a conventional polarized microscope and our cell-phone based system. The cell-phone based polarimetric microscopy design shows the potential to have both the resolution and specificity to detect malaria in a low-cost, easy-to-use, modular platform.

Imaging microscopic structures in pathological retinas using a flood-illumination adaptive optics retinal camera

NASA Astrophysics Data System (ADS)

Viard, Clément; Nakashima, Kiyoko; Lamory, Barbara; Pâques, Michel; Levecq, Xavier; Château, Nicolas

2011-03-01

This research is aimed at characterizing in vivo differences between healthy and pathological retinal tissues at the microscopic scale using a compact adaptive optics (AO) retinal camera. Tests were performed in 120 healthy eyes and 180 eyes suffering from 19 different pathological conditions, including age-related maculopathy (ARM), glaucoma and rare diseases such as inherited retinal dystrophies. Each patient was first examined using SD-OCT and infrared SLO. Retinal areas of 4°x4° were imaged using an AO flood-illumination retinal camera based on a large-stroke deformable mirror. Contrast was finally enhanced by registering and averaging rough images using classical algorithms. Cellular-resolution images could be obtained in most cases. In ARM, AO images revealed granular contents in drusen, which were invisible in SLO or OCT images, and allowed the observation of the cone mosaic between drusen. In glaucoma cases, visual field was correlated to changes in cone visibility. In inherited retinal dystrophies, AO helped to evaluate cone loss across the retina. Other microstructures, slightly larger in size than cones, were also visible in several retinas. AO provided potentially useful diagnostic and prognostic information in various diseases. In addition to cones, other microscopic structures revealed by AO images may also be of interest in monitoring retinal diseases.

Malaria Diagnosis Using a Mobile Phone Polarized Microscope

PubMed Central

Pirnstill, Casey W.; Coté, Gerard L.

2015-01-01

Malaria remains a major global health burden, and new methods for low-cost, high-sensitivity, diagnosis are essential, particularly in remote areas with low-resource around the world. In this paper, a cost effective, optical cell-phone based transmission polarized light microscope system is presented for imaging the malaria pigment known as hemozoin. It can be difficult to determine the presence of the pigment from background and other artifacts, even for skilled microscopy technicians. The pigment is much easier to observe using polarized light microscopy. However, implementation of polarized light microscopy lacks widespread adoption because the existing commercial devices have complicated designs, require sophisticated maintenance, tend to be bulky, can be expensive, and would require re-training for existing microscopy technicians. To this end, a high fidelity and high optical resolution cell-phone based polarized light microscopy system is presented which is comparable to larger bench-top polarized microscopy systems but at much lower cost and complexity. The detection of malaria in fixed and stained blood smears is presented using both, a conventional polarized microscope and our cell-phone based system. The cell-phone based polarimetric microscopy design shows the potential to have both the resolution and specificity to detect malaria in a low-cost, easy-to-use, modular platform. PMID:26303238

Portable and cost-effective pixel super-resolution on-chip microscope for telemedicine applications.

PubMed

Bishara, Waheb; Sikora, Uzair; Mudanyali, Onur; Su, Ting-Wei; Yaglidere, Oguzhan; Luckhart, Shirley; Ozcan, Aydogan

2011-01-01

We report a field-portable lensless on-chip microscope with a lateral resolution of <1 μm and a large field-of-view of ~24 mm(2). This microscope is based on digital in-line holography and a pixel super-resolution algorithm to process multiple lensfree holograms and obtain a single high-resolution hologram. In its compact and cost-effective design, we utilize 23 light emitting diodes butt-coupled to 23 multi-mode optical fibers, and a simple optical filter, with no moving parts. Weighing only ~95 grams, we demonstrate the performance of this field-portable microscope by imaging various objects including human malaria parasites in thin blood smears.

Optics of high-performance electron microscopes*

PubMed Central

Rose, H H

2008-01-01

During recent years, the theory of charged particle optics together with advances in fabrication tolerances and experimental techniques has lead to very significant advances in high-performance electron microscopes. Here, we will describe which theoretical tools, inventions and designs have driven this development. We cover the basic theory of higher-order electron optics and of image formation in electron microscopes. This leads to a description of different methods to correct aberrations by multipole fields and to a discussion of the most advanced design that take advantage of these techniques. The theory of electron mirrors is developed and it is shown how this can be used to correct aberrations and to design energy filters. Finally, different types of energy filters are described. PMID:27877933

Review on Microstructure Analysis of Metals and Alloys Using Image Analysis Techniques

NASA Astrophysics Data System (ADS)

Rekha, Suganthini; Bupesh Raja, V. K.

2017-05-01

The metals and alloys find vast application in engineering and domestic sectors. The mechanical properties of the metals and alloys are influenced by their microstructure. Hence the microstructural investigation is very critical. Traditionally the microstructure is studied using optical microscope with suitable metallurgical preparation. The past few decades the computers are applied in the capture and analysis of the optical micrographs. The advent of computer softwares like digital image processing and computer vision technologies are a boon to the analysis of the microstructure. In this paper the literature study of the various developments in the microstructural analysis, is done. The conventional optical microscope is complemented by the use of Scanning Electron Microscope (SEM) and other high end equipments.

Quantum coherent optical phase modulation in an ultrafast transmission electron microscope.

PubMed

Feist, Armin; Echternkamp, Katharina E; Schauss, Jakob; Yalunin, Sergey V; Schäfer, Sascha; Ropers, Claus

2015-05-14

Coherent manipulation of quantum systems with light is expected to be a cornerstone of future information and communication technology, including quantum computation and cryptography. The transfer of an optical phase onto a quantum wavefunction is a defining aspect of coherent interactions and forms the basis of quantum state preparation, synchronization and metrology. Light-phase-modulated electron states near atoms and molecules are essential for the techniques of attosecond science, including the generation of extreme-ultraviolet pulses and orbital tomography. In contrast, the quantum-coherent phase-modulation of energetic free-electron beams has not been demonstrated, although it promises direct access to ultrafast imaging and spectroscopy with tailored electron pulses on the attosecond scale. Here we demonstrate the coherent quantum state manipulation of free-electron populations in an electron microscope beam. We employ the interaction of ultrashort electron pulses with optical near-fields to induce Rabi oscillations in the populations of electron momentum states, observed as a function of the optical driving field. Excellent agreement with the scaling of an equal-Rabi multilevel quantum ladder is obtained, representing the observation of a light-driven 'quantum walk' coherently reshaping electron density in momentum space. We note that, after the interaction, the optically generated superposition of momentum states evolves into a train of attosecond electron pulses. Our results reveal the potential of quantum control for the precision structuring of electron densities, with possible applications ranging from ultrafast electron spectroscopy and microscopy to accelerator science and free-electron lasers.

Quantum coherent optical phase modulation in an ultrafast transmission electron microscope

NASA Astrophysics Data System (ADS)

Feist, Armin; Echternkamp, Katharina E.; Schauss, Jakob; Yalunin, Sergey V.; Schäfer, Sascha; Ropers, Claus

2015-05-01

Coherent manipulation of quantum systems with light is expected to be a cornerstone of future information and communication technology, including quantum computation and cryptography. The transfer of an optical phase onto a quantum wavefunction is a defining aspect of coherent interactions and forms the basis of quantum state preparation, synchronization and metrology. Light-phase-modulated electron states near atoms and molecules are essential for the techniques of attosecond science, including the generation of extreme-ultraviolet pulses and orbital tomography. In contrast, the quantum-coherent phase-modulation of energetic free-electron beams has not been demonstrated, although it promises direct access to ultrafast imaging and spectroscopy with tailored electron pulses on the attosecond scale. Here we demonstrate the coherent quantum state manipulation of free-electron populations in an electron microscope beam. We employ the interaction of ultrashort electron pulses with optical near-fields to induce Rabi oscillations in the populations of electron momentum states, observed as a function of the optical driving field. Excellent agreement with the scaling of an equal-Rabi multilevel quantum ladder is obtained, representing the observation of a light-driven `quantum walk' coherently reshaping electron density in momentum space. We note that, after the interaction, the optically generated superposition of momentum states evolves into a train of attosecond electron pulses. Our results reveal the potential of quantum control for the precision structuring of electron densities, with possible applications ranging from ultrafast electron spectroscopy and microscopy to accelerator science and free-electron lasers.

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.

Brain plasticity and functionality explored by nonlinear optical microscopy

NASA Astrophysics Data System (ADS)

Sacconi, L.; Allegra, L.; Buffelli, M.; Cesare, P.; D'Angelo, E.; Gandolfi, D.; Grasselli, G.; Lotti, J.; Mapelli, J.; Strata, P.; Pavone, F. S.

2010-02-01

In combination with fluorescent protein (XFP) expression techniques, two-photon microscopy has become an indispensable tool to image cortical plasticity in living mice. In parallel to its application in imaging, multi-photon absorption has also been used as a tool for the dissection of single neurites with submicrometric precision without causing any visible collateral damage to the surrounding neuronal structures. In this work, multi-photon nanosurgery is applied to dissect single climbing fibers expressing GFP in the cerebellar cortex. The morphological consequences are then characterized with time lapse 3-dimensional two-photon imaging over a period of minutes to days after the procedure. Preliminary investigations show that the laser induced fiber dissection recalls a regenerative process in the fiber itself over a period of days. These results show the possibility of this innovative technique to investigate regenerative processes in adult brain. In parallel with imaging and manipulation technique, non-linear microscopy offers the opportunity to optically record electrical activity in intact neuronal networks. In this work, we combined the advantages of second-harmonic generation (SHG) with a random access (RA) excitation scheme to realize a new microscope (RASH) capable of optically recording fast membrane potential events occurring in a wide-field of view. The RASH microscope, in combination with bulk loading of tissue with FM4-64 dye, was used to simultaneously record electrical activity from clusters of Purkinje cells in acute cerebellar slices. Complex spikes, both synchronous and asynchronous, were optically recorded simultaneously across a given population of neurons. Spontaneous electrical activity was also monitored simultaneously in pairs of neurons, where action potentials were recorded without averaging across trials. These results show the strength of this technique in describing the temporal dynamics of neuronal assemblies, opening promising perspectives in understanding the computations of neuronal networks.

Benchtop and animal validation of a portable fluorescence microscopic imaging system for potential use in cholecystectomy.

PubMed

Ye, Jian; Liu, Guanghui; Liu, Peng; Zhang, Shiwu; Shao, Pengfei; Smith, Zachary J; Liu, Chenhai; Xu, Ronald X

2018-02-01

We propose a portable fluorescence microscopic imaging system (PFMS) for intraoperative display of biliary structure and prevention of iatrogenic injuries during cholecystectomy. The system consists of a light source module, a camera module, and a Raspberry Pi computer with an LCD. Indocyanine green (ICG) is used as a fluorescent contrast agent for experimental validation of the system. Fluorescence intensities of the ICG aqueous solution at different concentration levels are acquired by our PFMS and compared with those of a commercial Xenogen IVIS system. We study the fluorescence detection depth by superposing different thicknesses of chicken breast on an ICG-loaded agar phantom. We verify the technical feasibility for identifying potential iatrogenic injury in cholecystectomy using a rat model in vivo. The proposed PFMS system is portable, inexpensive, and suitable for deployment in resource-limited settings. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Lensless digital holographic microscopy and its applications in biomedicine and environmental monitoring.

PubMed

Wu, Yichen; Ozcan, Aydogan

2018-03-01

Optical compound microscope has been a major tool in biomedical imaging for centuries. Its performance relies on relatively complicated, bulky and expensive lenses and alignment mechanics. In contrast, the lensless microscope digitally reconstructs microscopic images of specimens without using any lenses, as a result of which it can be made much smaller, lighter and lower-cost. Furthermore, the limited space-bandwidth product of objective lenses in a conventional microscope can be significantly surpassed by a lensless microscope. Such lensless imaging designs have enabled high-resolution and high-throughput imaging of specimens using compact, portable and cost-effective devices to potentially address various point-of-care, global-health and telemedicine related challenges. In this review, we discuss the operation principles and the methods behind lensless digital holographic on-chip microscopy. We also go over various applications that are enabled by cost-effective and compact implementations of lensless microscopy, including some recent work on air quality monitoring, which utilized machine learning for high-throughput and accurate quantification of particulate matter in air. Finally, we conclude with a brief future outlook of this computational imaging technology. Copyright © 2017 Elsevier Inc. All rights reserved.

Corrosion resistance evaluation of Pd-free Ag-Au-Pt-Cu dental alloys.

PubMed

Fujita, Takeshi; Shiraishi, Takanobu; Takuma, Yasuko; Hisatsune, Kunihiro

2011-01-01

The corrosion resistance of nine experimental Pd-free Ag-Au-Pt-Cu dental alloys in a 0.9% NaCl solution was investigated using cyclic voltammetry (CV), optical microscopy, and scanning electron microscopy (SEM). CV measurements revealed that the breakdown potential (E(bd)) and zero current potential (E(zc)) increased with increasing Au/(Au+Ag) atomic ratio. Thus, the Au/(Au+Ag) atomic ratio, but not the Cu content, influenced the corrosion resistance of Ag-Au-Pt-Cu alloys. After the forward scan of CV, both optical and scanning electron microscope images showed that in all the experimental alloys, the matrix phase was corroded but not the second phase. From corrosion resistance viewpoint, the Ag-Au-Pt-Cu alloys seemed to be suitable for clinical application.

Design, Fabrication and Testing of Multilayer Coated X-Ray Optics for the Water Window Imaging X-Ray Microscope

NASA Technical Reports Server (NTRS)

Spencer, Dwight C.

1996-01-01

Hoover et. al. built and tested two imaging Schwarzschild multilayer microscopes. These instruments were constructed as prototypes for the "Water Window Imaging X-Ray Microscope," which is a doubly reflecting, multilayer x-ray microscope configured to operate within the "water window." The "water window" is the narrow region of the x-ray spectrum between the K absorption edges of oxygen (lamda = 23.3 Angstroms) and of carbon (lamda = 43.62 Angstroms), where water is relatively highly transmissive and carbon is highly absorptive. This property of these materials, thus permits the use of high resolution multilayer x-ray microscopes for producing high contrast images of carbon-based structures within the aqueous physiological environments of living cells. We report the design, fabrication and testing of multilayer optics that operate in this regime.

Hyperspectral microscope for in vivo imaging of microstructures and cells in tissues

DOEpatents

Demos,; Stavros, G [Livermore, CA

2011-05-17

An optical hyperspectral/multimodal imaging method and apparatus is utilized to provide high signal sensitivity for implementation of various optical imaging approaches. Such a system utilizes long working distance microscope objectives so as to enable off-axis illumination of predetermined tissue thereby allowing for excitation at any optical wavelength, simplifies design, reduces required optical elements, significantly reduces spectral noise from the optical elements and allows for fast image acquisition enabling high quality imaging in-vivo. Such a technology provides a means of detecting disease at the single cell level such as cancer, precancer, ischemic, traumatic or other type of injury, infection, or other diseases or conditions causing alterations in cells and tissue micro structures.

Resolution and throughput optimized intraoperative spectrally encoded coherence tomography and reflectometry (iSECTR) for multimodal imaging during ophthalmic microsurgery

NASA Astrophysics Data System (ADS)

Malone, Joseph D.; El-Haddad, Mohamed T.; Leeburg, Kelsey C.; Terrones, Benjamin D.; Tao, Yuankai K.

2018-02-01

Limited visualization of semi-transparent structures in the eye remains a critical barrier to improving clinical outcomes and developing novel surgical techniques. While increases in imaging speed has enabled intraoperative optical coherence tomography (iOCT) imaging of surgical dynamics, several critical barriers to clinical adoption remain. Specifically, these include (1) static field-of-views (FOVs) requiring manual instrument-tracking; (2) high frame-rates require sparse sampling, which limits FOV; and (3) small iOCT FOV also limits the ability to co-register data with surgical microscopy. We previously addressed these limitations in image-guided ophthalmic microsurgery by developing microscope-integrated multimodal intraoperative swept-source spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography. Complementary en face images enabled orientation and coregistration with the widefield surgical microscope view while OCT imaging enabled depth-resolved visualization of surgical instrument positions relative to anatomic structures-of-interest. In addition, we demonstrated novel integrated segmentation overlays for augmented-reality surgical guidance. Unfortunately, our previous system lacked the resolution and optical throughput for in vivo retinal imaging and necessitated removal of cornea and lens. These limitations were predominately a result of optical aberrations from imaging through a shared surgical microscope objective lens, which was modeled as a paraxial surface. Here, we present an optimized intraoperative spectrally encoded coherence tomography and reflectometry (iSECTR) system. We use a novel lens characterization method to develop an accurate model of surgical microscope objective performance and balance out inherent aberrations using iSECTR relay optics. Using this system, we demonstrate in vivo multimodal ophthalmic imaging through a surgical microscope

Skin suturing and cortical surface viral infusion improves imaging of neuronal ensemble activity with head-mounted miniature microscopes.

PubMed

Li, Xinjian; Cao, Vania Y; Zhang, Wenyu; Mastwal, Surjeet S; Liu, Qing; Otte, Stephani; Wang, Kuan Hong

2017-11-01

In vivo optical imaging of neural activity provides important insights into brain functions at the single-cell level. Cranial windows and virally delivered calcium indicators are commonly used for imaging cortical activity through two-photon microscopes in head-fixed animals. Recently, head-mounted one-photon microscopes have been developed for freely behaving animals. However, minimizing tissue damage from the virus injection procedure and maintaining window clarity for imaging can be technically challenging. We used a wide-diameter glass pipette at the cortical surface for infusing the viral calcium reporter AAV-GCaMP6 into the cortex. After infusion, the scalp skin over the implanted optical window was sutured to facilitate postoperative recovery. The sutured scalp was removed approximately two weeks later and a miniature microscope was attached above the window to image neuronal activity in freely moving mice. We found that cortical surface virus infusion efficiently labeled neurons in superficial layers, and scalp skin suturing helped to maintain the long-term clarity of optical windows. As a result, several hundred neurons could be recorded in freely moving animals. Compared to intracortical virus injection and open-scalp postoperative recovery, our methods minimized tissue damage and dura overgrowth underneath the optical window, and significantly increased the experimental success rate and the yield of identified neurons. Our improved cranial surgery technique allows for high-yield calcium imaging of cortical neurons with head-mounted microscopes in freely behaving animals. This technique may be beneficial for other optical applications such as two-photon microscopy, multi-site imaging, and optogenetic modulation. Published by Elsevier B.V.

Optical potential from first principles

DOE PAGES

Rotureau, J.; Danielewicz, P.; Hagen, G.; ...

2017-02-15

Here, we develop a method to construct a microscopic optical potential from chiral interactions for nucleon-nucleus scattering. The optical potential is constructed by combining the Green’s function approach with the coupled-cluster method. To deal with the poles of the Green’s function along the real energy axis we employ a Berggren basis in the complex energy plane combined with the Lanczos method. Using this approach, we perform a proof-of-principle calculation of the optical potential for the elastic neutron scattering on 16O. For the computation of the ground-state of 16O, we use the coupled-cluster method in the singles-and-doubles approximation, while for themore » A ±1 nuclei we use particle-attached/removed equation-of-motion method truncated at two-particle-one-hole and one-particle-two-hole excitations, respectively. We verify the convergence of the optical potential and scattering phase shifts with respect to the model-space size and the number of discretized complex continuum states. We also investigate the absorptive component of the optical potential (which reflects the opening of inelastic channels) by computing its imaginary volume integral and find an almost negligible absorptive component at low-energies. To shed light on this result, we computed excited states of 16O using equation-of-motion coupled-cluster method with singles-and- doubles excitations and we found no low-lying excited states below 10 MeV. Furthermore, most excited states have a dominant two-particle-two-hole component, making higher-order particle-hole excitations necessary to achieve a precise description of these core-excited states. We conclude that the reduced absorption at low-energies can be attributed to the lack of correlations coming from the low-order cluster truncation in the employed coupled-cluster method.« less

In vivo imaging of oral neoplasia using a miniaturized fiber optic confocal reflectance microscope.

PubMed

Maitland, Kristen C; Gillenwater, Ann M; Williams, Michelle D; El-Naggar, Adel K; Descour, Michael R; Richards-Kortum, Rebecca R

2008-11-01

The purpose of this study was to determine whether in vivo images of oral mucosa obtained with a fiber optic confocal reflectance microscope could be used to differentiate normal and neoplastic tissues. We imaged 20 oral sites in eight patients undergoing surgery for squamous cell carcinoma. Normal and abnormal areas within the oral cavity were identified clinically, and real-time videos of each site were obtained in vivo using a fiber optic confocal reflectance microscope. Following imaging, each site was biopsied and submitted for histopathologic examination. We identified distinct features, such as nuclear irregularity and spacing, which can be used to qualitatively differentiate between normal and abnormal tissue. Representative confocal images of normal, pre-neoplastic, and neoplastic oral tissue are presented. Previous work using much larger microscopes has demonstrated the ability of confocal reflectance microscopy to image cellular and tissue architecture in situ. New advances in technology have enabled miniaturization of imaging systems for in vivo use.

Sensing of Streptococcus mutans by microscopic imaging ellipsometry

NASA Astrophysics Data System (ADS)

Khaleel, Mai Ibrahim; Chen, Yu-Da; Chien, Ching-Hang; Chang, Yia-Chung

2017-05-01

Microscopic imaging ellipsometry is an optical technique that uses an objective and sensing procedure to measure the ellipsometric parameters Ψ and Δ in the form of microscopic maps. This technique is well known for being noninvasive and label-free. Therefore, it can be used to detect and characterize biological species without any impact. Microscopic imaging ellipsometry was used to measure the optical response of dried Streptococcus mutans cells on a glass substrate. The ellipsometric Ψ and Δ maps were obtained with the Optrel Multiskop system for specular reflection in the visible range (λ=450 to 750 nm). The Ψ and Δ images at 500, 600, and 700 nm were analyzed using three different theoretical models with single-bounce, two-bounce, and multibounce light paths to obtain the optical constants and height distribution. The obtained images of the optical constants show different aspects when comparing the single-bounce analysis with the two-bounce or multibounce analysis in detecting S. mutans samples. Furthermore, the height distributions estimated by two-bounce and multibounce analyses of S. mutans samples were in agreement with the thickness values measured by AFM, which implies that the two-bounce and multibounce analyses can provide information complementary to that obtained by a single-bounce light path.

Review of advanced imaging techniques

PubMed Central

Chen, Yu; Liang, Chia-Pin; Liu, Yang; Fischer, Andrew H.; Parwani, Anil V.; Pantanowitz, Liron

2012-01-01

Pathology informatics encompasses digital imaging and related applications. Several specialized microscopy techniques have emerged which permit the acquisition of digital images (“optical biopsies”) at high resolution. Coupled with fiber-optic and micro-optic components, some of these imaging techniques (e.g., optical coherence tomography) are now integrated with a wide range of imaging devices such as endoscopes, laparoscopes, catheters, and needles that enable imaging inside the body. These advanced imaging modalities have exciting diagnostic potential and introduce new opportunities in pathology. Therefore, it is important that pathology informaticists understand these advanced imaging techniques and the impact they have on pathology. This paper reviews several recently developed microscopic techniques, including diffraction-limited methods (e.g., confocal microscopy, 2-photon microscopy, 4Pi microscopy, and spatially modulated illumination microscopy) and subdiffraction techniques (e.g., photoactivated localization microscopy, stochastic optical reconstruction microscopy, and stimulated emission depletion microscopy). This article serves as a primer for pathology informaticists, highlighting the fundamentals and applications of advanced optical imaging techniques. PMID:22754737

Emerging fiber optic endomicroscopy technologies towards noninvasive real-time visualization of histology in situ

NASA Astrophysics Data System (ADS)

Xi, Jiefeng; Zhang, Yuying; Huo, Li; Chen, Yongping; Jabbour, Toufic; Li, Ming-Jun; Li, Xingde

2010-09-01

This paper reviews our recent developments of ultrathin fiber-optic endomicroscopy technologies for transforming high-resolution noninvasive optical imaging techniques to in vivo and clinical applications such as early disease detection and guidance of interventions. Specifically we describe an all-fiber-optic scanning endomicroscopy technology, which miniaturizes a conventional bench-top scanning laser microscope down to a flexible fiber-optic probe of a small footprint (i.e. ~2-2.5 mm in diameter), capable of performing two-photon fluorescence and second harmonic generation microscopy in real time. This technology aims to enable realtime visualization of histology in situ without the need for tissue removal. We will also present a balloon OCT endoscopy technology which permits high-resolution 3D imaging of the entire esophagus for detection of neoplasia, guidance of biopsy and assessment of therapeutic outcome. In addition we will discuss the development of functional polymeric fluorescent nanocapsules, which use only FAD approved materials and potentially enable fast track clinical translation of optical molecular imaging and targeted therapy.

Effects of neutron irradiation on optical and chemical properties of CR-39: Potential application in neutron dosimetry.

PubMed

Sahoo, G S; Paul, S; Tripathy, S P; Sharma, S C; Jena, S; Rout, S; Joshi, D S; Bandyopadhyay, T

2014-12-01

Effects of high-dose neutron irradiation on chemical and optical properties of CR-39 were studied using FTIR (Fourier Transform Infrared) and UV-vis (Ultraviolet-Visible) spectroscopy. The primary goal was to find a correlation between the neutron dose and the corresponding changes in the optical and chemical properties of CR-39 resulted from the neutron irradiation. The neutrons were produced by bombarding a thick Be target with 22-MeV protons. In the FTIR spectra, prominent absorbance peaks were observed at 1735cm(-1) (C=O stretching), 1230cm(-1)(C-O-C stretching), and 783cm(-1)(=C-H bending), the intensities of which decreased with increasing neutron dose. The optical absorbance in the visible range increased linearly with the neutron dose. Empirical relations were established to estimate neutron doses from these optical properties. This technique is particularly useful in measuring high doses, where track analysis with an optical microscope is difficult because of track overlapping. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optical analysis of a compound quasi-microscope for planetary landers

NASA Technical Reports Server (NTRS)

Wall, S. D.; Burcher, E. E.; Huck, F. O.

1974-01-01

A quasi-microscope concept, consisting of facsimile camera augmented with an auxiliary lens as a magnifier, was introduced and analyzed. The performance achievable with this concept was primarily limited by a trade-off between resolution and object field; this approach leads to a limiting resolution of 20 microns when used with the Viking lander camera (which has an angular resolution of 0.04 deg). An optical system is analyzed which includes a field lens between camera and auxiliary lens to overcome this limitation. It is found that this system, referred to as a compound quasi-microscope, can provide improved resolution (to about 2 microns ) and a larger object field. However, this improvement is at the expense of increased complexity, special camera design requirements, and tighter tolerances on the distances between optical components.

Analysis of 4He+40Ca and 4He+44Ti scattering using different optical model potentials

NASA Astrophysics Data System (ADS)

Ibraheem, Awad A.

2016-09-01

Elastic scattering of 4He+40Ca and 4He+44Ti reactions at backward angles has been analyzed using two differentmodels, microscopic and semimicroscopic folding potentials. The derived real potentials supplemented with phenomenological Woods-Saxon imaginary potentials, provide good agreement with the experimental data at energy E c.m. = 21.8 MeV without need to renormalize the potentials. Coupledchannels calculations are used to extract the inelastic scattering cross section to the low-lying state 2+ (1.083 MeV) of 44Ti. The deformation length is obtained and compared with the electromagnetic measurement values as well as those obtained from previous studies.

Measurement of fluorescence in a rhodamine-123 doped self-assembled "giant" mesostructured silica sphere using a smartphone as optical hardware.

PubMed

Canning, John; Lau, Angelica; Naqshbandi, Masood; Petermann, Ingemar; Crossley, Maxwell J

2011-01-01

The blue OLED emission from a mobile phone was characterised, revealing a sharp emission band centred at λ = 445 nm with a 3dB bandwidth Δλ ∼ 20 nm. It was used to excite Rhodamine 123 doped within a "giant" mesostructured silica sphere during fabrication through evaporative self-assembly of silica nanoparticles. Fluorescence was able to be detected using a standard optical microscope fitted with a green transmission pass filter and cooled CCD and with 1 ms exposure time demonstrating the potential of mobile platforms as the basis for portable diagnostics in the field.

A new computerized moving stage for optical microscopes

NASA Astrophysics Data System (ADS)

Hatiboglu, Can Ulas; Akin, Serhat

2004-06-01

Measurements of microscope stage movements in the x and y directions are of importance for some stereological methods. Traditionally, the length of stage movements is measured with differing precision and accuracy using a suitable motorized stage, a microscope and software. Such equipment is generally expensive and not readily available in many laboratories. One other challenging problem is the adaptability to available microscope systems which weakens the possibility of the equipment to be used with any kind of light microscope. This paper describes a simple and cheap programmable moving stage that can be used with the available microscopes in the market. The movements of the stage are controlled by two servo-motors and a controller chip via a Java-based image processing software. With the developed motorized stage and a microscope equipped with a CCD camera, the software allows complete coverage of the specimens with minimum overlap, eliminating the optical strain associated with counting hundreds of images through an eyepiece, in a quick and precise fashion. The uses and the accuracy of the developed stage are demonstrated using thin sections obtained from a limestone core plug.

Enhancing the performance of the light field microscope using wavefront coding.

PubMed

Cohen, Noy; Yang, Samuel; Andalman, Aaron; Broxton, Michael; Grosenick, Logan; Deisseroth, Karl; Horowitz, Mark; Levoy, Marc

2014-10-06

Light field microscopy has been proposed as a new high-speed volumetric computational imaging method that enables reconstruction of 3-D volumes from captured projections of the 4-D light field. Recently, a detailed physical optics model of the light field microscope has been derived, which led to the development of a deconvolution algorithm that reconstructs 3-D volumes with high spatial resolution. However, the spatial resolution of the reconstructions has been shown to be non-uniform across depth, with some z planes showing high resolution and others, particularly at the center of the imaged volume, showing very low resolution. In this paper, we enhance the performance of the light field microscope using wavefront coding techniques. By including phase masks in the optical path of the microscope we are able to address this non-uniform resolution limitation. We have also found that superior control over the performance of the light field microscope can be achieved by using two phase masks rather than one, placed at the objective's back focal plane and at the microscope's native image plane. We present an extended optical model for our wavefront coded light field microscope and develop a performance metric based on Fisher information, which we use to choose adequate phase masks parameters. We validate our approach using both simulated data and experimental resolution measurements of a USAF 1951 resolution target; and demonstrate the utility for biological applications with in vivo volumetric calcium imaging of larval zebrafish brain.

Optical fabrication and testing; Proceedings of the Meeting, Singapore, Oct. 22-27, 1990

NASA Astrophysics Data System (ADS)

Lorenzen, Manfred; Campbell, Duncan R.; Johnson, Craig W.

1991-03-01

Various papers on optical fabrication and testing are presented. Individual topics addressed include: interferometry with laser diodes, new methods for economic production of prisms and lenses, interferometer accuracy and precision, optical testing with wavelength scanning interferometer, digital Talbot interferometer, high-sensitivity interferometric technique for strain measurements, absolute interferometric testing of spherical surfaces, contouring using gratings created on an LCD panel, three-dimensional inspection using laser-based dynamic fringe projection, noncontact optical microtopography, laser scan microscope and infrared laser scan microscope, photon scanning tunneling microscopy. Also discussed are: combination-matching problems in the layout design of minilaser rangefinder, design and testing of a cube-corner array for laser ranging, mode and far-field pattern of diode laser-phased arrays, new glasses for optics and optoelectronics, optical properties of Li-doped ZnO films, application and machining of Zerodur for optical purposes, finish machining of optical components in mass production.

Scanning optical microscope with long working distance objective

DOEpatents

Cloutier, Sylvain G.

2010-10-19

A scanning optical microscope, including: a light source to generate a beam of probe light; collimation optics to substantially collimate the probe beam; a probe-result beamsplitter; a long working-distance, infinity-corrected objective; scanning means to scan a beam spot of the focused probe beam on or within a sample; relay optics; and a detector. The collimation optics are disposed in the probe beam. The probe-result beamsplitter is arranged in the optical paths of the probe beam and the resultant light from the sample. The beamsplitter reflects the probe beam into the objective and transmits resultant light. The long working-distance, infinity-corrected objective is also arranged in the optical paths of the probe beam and the resultant light. It focuses the reflected probe beam onto the sample, and collects and substantially collimates the resultant light. The relay optics are arranged to relay the transmitted resultant light from the beamsplitter to the detector.

Experimental stress–strain analysis of tapered silica optical fibers with nanofiber waist

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holleis, S.; Hoinkes, T.; Wuttke, C.

2014-04-21

We experimentally determine tensile force–elongation diagrams of tapered optical fibers with a nanofiber waist. The tapered optical fibers are produced from standard silica optical fibers using a heat and pull process. Both, the force–elongation data and scanning electron microscope images of the rupture points indicate a brittle material. Despite the small waist radii of only a few hundred nanometers, our experimental data can be fully explained by a nonlinear stress–strain model that relies on material properties of macroscopic silica optical fibers. This is an important asset when it comes to designing miniaturized optical elements as one can rely on themore » well-founded material characteristics of standard optical fibers. Based on this understanding, we demonstrate a simple and non-destructive technique that allows us to determine the waist radius of the tapered optical fiber. We find excellent agreement with independent scanning electron microscope measurements of the waist radius.« less

Optical fabrication and testing; Proceedings of the Meeting, Singapore, Oct. 22-27, 1990

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lorenzen, M.; Campbell, D.R.; Johnson, C.W.

1991-01-01

Various papers on optical fabrication and testing are presented. Individual topics addressed include: interferometry with laser diodes, new methods for economic production of prisms and lenses, interferometer accuracy and precision, optical testing with wavelength scanning interferometer, digital Talbot interferometer, high-sensitivity interferometric technique for strain measurements, absolute interferometric testing of spherical surfaces, contouring using gratings created on an LCD panel, three-dimensional inspection using laser-based dynamic fringe projection, noncontact optical microtopography, laser scan microscope and infrared laser scan microscope, photon scanning tunneling microscopy. Also discussed are: combination-matching problems in the layout design of minilaser rangefinder, design and testing of a cube-corner arraymore » for laser ranging, mode and far-field pattern of diode laser-phased arrays, new glasses for optics and optoelectronics, optical properties of Li-doped ZnO films, application and machining of Zerodur for optical purposes, finish machining of optical components in mass production.« less

Aqueous carrier waveguide in a flow cytometer

DOEpatents

Mariella, Jr., Raymond P.; van den Engh, Gerrit; Northrup, M. Allen

1995-01-01

The liquid of a flow cytometer itself acts as an optical waveguide, thus transmitting the light to an optical filter/detector combination. This alternative apparatus and method for detecting scattered light in a flow cytometer is provided by a device which views and detects the light trapped within the optical waveguide formed by the flow stream. A fiber optic or other light collecting device is positioned within the flow stream. This provides enormous advantages over the standard light collection technique which uses a microscope objective. The signal-to-noise ratio is greatly increased over that for right-angle-scattered light collected by a microscope objective, and the alignment requirements are simplified.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Attota, Ravikiran, E-mail: Ravikiran.attota@nist.gov; Dixson, Ronald G.

We experimentally demonstrate that the three-dimensional (3-D) shape variations of nanometer-scale objects can be resolved and measured with sub-nanometer scale sensitivity using conventional optical microscopes by analyzing 4-D optical data using the through-focus scanning optical microscopy (TSOM) method. These initial results show that TSOM-determined cross-sectional (3-D) shape differences of 30 nm–40 nm wide lines agree well with critical-dimension atomic force microscope measurements. The TSOM method showed a linewidth uncertainty of 1.22 nm (k = 2). Complex optical simulations are not needed for analysis using the TSOM method, making the process simple, economical, fast, and ideally suited for high volume nanomanufacturing process monitoring.

Optical microscope and tapered fiber coupling apparatus for a dilution refrigerator.

PubMed

MacDonald, A J R; Popowich, G G; Hauer, B D; Kim, P H; Fredrick, A; Rojas, X; Doolin, P; Davis, J P

2015-01-01

We have developed a system for tapered fiber measurements of optomechanical resonators inside a dilution refrigerator, which is compatible with both on- and off-chip devices. Our apparatus features full three-dimensional control of the taper-resonator coupling conditions enabling critical coupling, with an overall fiber transmission efficiency of up to 70%. Notably, our design incorporates an optical microscope system consisting of a coherent bundle of 37,000 optical fibers for real-time imaging of the experiment at a resolution of ∼1 μm. We present cryogenic optical and optomechanical measurements of resonators coupled to tapered fibers at temperatures as low as 9 mK.

Design and analysis of a fast, two-mirror soft-x-ray microscope

NASA Technical Reports Server (NTRS)

Shealy, D. L.; Wang, C.; Jiang, W.; Jin, L.; Hoover, R. B.

1992-01-01

During the past several years, a number of investigators have addressed the design, analysis, fabrication, and testing of spherical Schwarzschild microscopes for soft-x-ray applications using multilayer coatings. Some of these systems have demonstrated diffraction limited resolution for small numerical apertures. Rigorously aplanatic, two-aspherical mirror Head microscopes can provide near diffraction limited resolution for very large numerical apertures. The relationships between the numerical aperture, mirror radii and diameters, magnifications, and total system length for Schwarzschild microscope configurations are summarized. Also, an analysis of the characteristics of the Head-Schwarzschild surfaces will be reported. The numerical surface data predicted by the Head equations were fit by a variety of functions and analyzed by conventional optical design codes. Efforts have been made to determine whether current optical substrate and multilayer coating technologies will permit construction of a very fast Head microscope which can provide resolution approaching that of the wavelength of the incident radiation.

Optical sectioning microscopes with no moving parts using a micro-stripe array light emitting diode.

PubMed

Poher, V; Zhang, H X; Kennedy, G T; Griffin, C; Oddos, S; Gu, E; Elson, D S; Girkin, M; French, P M W; Dawson, M D; Neil, M A

2007-09-03

We describe an optical sectioning microscopy system with no moving parts based on a micro-structured stripe-array light emitting diode (LED). By projecting arbitrary line or grid patterns onto the object, we are able to implement a variety of optical sectioning microscopy techniques such as grid-projection structured illumination and line scanning confocal microscopy, switching from one imaging technique to another without modifying the microscope setup. The micro-structured LED and driver are detailed and depth discrimination capabilities are measured and calculated.

4Pi Microscopy.

PubMed

Schmidt, Roman; Engelhardt, Johann; Lang, Marion

2013-01-01

Optical microscopy has become a key technology in the life sciences today. Its noninvasive nature provides access to the interior of intact and even living cells, where specific molecules can be precisely localized by fluorescent tagging. However, the attainable 3D resolution of an optical microscope has long been hampered by a comparatively poor resolution along the optic axis. By coherent focusing through two objective lenses, 4Pi microscopy improves the axial resolution by three- to fivefold. This primer is intended as a starting point for the design and operation of a 4Pi microscope of type A.

Operation of a wet near-field scanning optical microscope in stable zones by minimizing the resonance change of tuning forks.

PubMed

Park, Kyoung-Duck; Park, Doo Jae; Lee, Seung Gol; Choi, Geunchang; Kim, Dai-Sik; Byeon, Clare Chisu; Choi, Soo Bong; Jeong, Mun Seok

2014-02-21

A resonant shift and a decrease of resonance quality of a tuning fork attached to a conventional fiber optic probe in the vicinity of liquid is monitored systematically while varying the protrusion length and immersion depth of the probe. Stable zones where the resonance modification as a function of immersion depth is minimized are observed. A wet near-field scanning optical microscope (wet-NSOM) is operated for a sample within water by using such a stable zone.

Solid state optical microscope

DOEpatents

Young, I.T.

1983-08-09

A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal. 2 figs.

Solid-state optical microscope

DOEpatents

Young, I.T.

1981-01-07

A solid state optical microscope is described wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. Means for scanning in one of two orthogonal directions are provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

Solid state optical microscope

DOEpatents

Young, Ian T.

1983-01-01

A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

Shape oscillations of microparticles on an optical microscope stage.

PubMed

Zhu, Z M; Apfel, R E

1985-11-01

A modulated acoustic radiation pressure technique to produce quadrupole shape oscillations of drops ranging in diameter from 50-220 micron has been used by us. These drops have been suspended by acoustic levitation in a small chamber mounted on a stage of an optical microscope, which allowed easy viewing. The fission of drops and the deformation of sea urchin eggs were also observed.

Joint Services Electronics Program Annual Progress Report.

DTIC Science & Technology

1987-10-15

polarizability of free carriers in the semiconductor perturb the index of refraction which can be detected in a Nomarski -type optical interferometer. For...interferomters. However, the charge probe relies on a different physical effect and operates by interferometrically detecting the phase change induced in an... Nomarski microscope systems. These techniques will be applied, eventually, in our real-time V.. scanning optical microscope described below. Recently

EnLightenment: High resolution smartphone microscopy as an educational and public engagement platform

PubMed Central

Wicks, Laura C.; Cairns, Gemma S.; Melnyk, Jacob; Bryce, Scott; Duncan, Rory R.; Dalgarno, Paul A.

2018-01-01

We developed a simple, cost-effective smartphone microscopy platform for use in educational and public engagement programs. We demonstrated its effectiveness, and potential for citizen science through a national imaging initiative, EnLightenment. The cost effectiveness of the instrument allowed for the program to deliver over 500 microscopes to more than 100 secondary schools throughout Scotland, targeting 1000’s of 12-14 year olds. Through careful, quantified, selection of a high power, low-cost objective lens, our smartphone microscope has an imaging resolution of microns, with a working distance of 3 mm. It is therefore capable of imaging single cells and sub-cellular features, and retains usability for young children. The microscopes were designed in kit form and provided an interdisciplinary educational tool. By providing full lesson plans and support material, we developed a framework to explore optical design, microscope performance, engineering challenges on construction and real-world applications in life sciences, biological imaging, marine biology, art, and technology. A national online imaging competition framed EnLightenment ; with over 500 high quality images submitted of diverse content, spanning multiple disciplines. With examples of cellular and sub-cellular features clearly identifiable in some submissions, we show how young public can use these instruments for research-level imaging applications, and the potential of the instrument for citizen science programs. PMID:29623296

Stage scoring of liver fibrosis using Mueller matrix microscope

NASA Astrophysics Data System (ADS)

Zhou, Jialing; He, Honghui; Wang, Ye; Ma, Hui

2016-10-01

Liver fibrosis is a common pathological process of varied chronic liver diseases including alcoholic hepatitis, virus hepatitis, and so on. Accurate evaluation of liver fibrosis is necessary for effective therapy and a five-stage grading system was developed. Currently, experienced pathologists use stained liver biopsies to assess the degree of liver fibrosis. But it is difficult to obtain highly reproducible results because of huge discrepancy among different observers. Polarization imaging technique has the potential of scoring liver fibrosis since it is capable of probing the structural and optical properties of samples. Considering that the Mueller matrix measurement can provide comprehensive microstructural information of the tissues, in this paper, we apply the Mueller matrix microscope to human liver fibrosis slices in different fibrosis stages. We extract the valid regions and adopt the Mueller matrix polar decomposition (MMPD) and Mueller matrix transformation (MMT) parameters for quantitative analysis. We also use the Monte Carlo simulation to analyze the relationship between the microscopic Mueller matrix parameters and the characteristic structural changes during the fibrosis process. The experimental and Monte Carlo simulated results show good consistency. We get a positive correlation between the parameters and the stage of liver fibrosis. The results presented in this paper indicate that the Mueller matrix microscope can provide additional information for the detections and fibrosis scorings of liver tissues and has great potential in liver fibrosis diagnosis.

Enhanced and selective optical trapping in a slot-graphite photonic crystal.

PubMed

Krishnan, Aravind; Huang, Ningfeng; Wu, Shao-Hua; Martínez, Luis Javier; Povinelli, Michelle L

2016-10-03

Applicability of optical trapping tools for nanomanipulation is limited by the available laser power and trap efficiency. We utilized the strong confinement of light in a slot-graphite photonic crystal to develop high-efficiency parallel trapping over a large area. The stiffness is 35 times higher than our previously demonstrated on-chip, near field traps. We demonstrate the ability to trap both dielectric and metallic particles of sub-micron size. We find that the growth kinetics of nanoparticle arrays on the slot-graphite template depends on particle size. This difference is exploited to selectively trap one type of particle out of a binary colloidal mixture, creating an efficient optical sieve. This technique has rich potential for analysis, diagnostics, and enrichment and sorting of microscopic entities.

Effect of etching time on morphological, optical, and electronic properties of silicon nanowires.

PubMed

Nafie, Nesma; Lachiheb, Manel Abouda; Bouaicha, Mongi

2012-07-16

Owing to their interesting electronic, mechanical, optical, and transport properties, silicon nanowires (SiNWs) have attracted much attention, giving opportunities to several potential applications in nanoscale electronic, optoelectronic devices, and silicon solar cells. For photovoltaic application, a superficial film of SiNWs could be used as an efficient antireflection coating. In this work we investigate the morphological, optical, and electronic properties of SiNWs fabricated at different etching times. Characterizations of the formed SiNWs films were performed using a scanning electron microscope, ultraviolet-visible-near-infrared spectroscopy, and light-beam-induced-current technique. The latter technique was used to determine the effective diffusion length in SiNWs films. From these investigations, we deduce that the homogeneity of the SiNWs film plays a key role on the electronic properties.

Plastic fiber optics for micro-imaging of fluorescence signals in living cells

NASA Astrophysics Data System (ADS)

Sakurai, Takashi; Natsume, Mitsuo; Koida, Kowa

2015-03-01

The fiber-coupled microscope (FCM) enables in vivo imaging at deep sites in the tissues or organs that other optical techniques are unable to reach. To develop FCM-based intravital imaging, we employed a plastic optical fiber (POF) bundle that included more than 10,000-units of polystyrene core and polymethyl methacrylate cladding. Each POF had a diameter of less than 5 μm the tip of the bundle was less than 0.5 mm wide, and the flexible wire had a length of 1,000 mm. The optical performance of the plastic FCM was sufficient for detection of significant signal changes in an acinus of rat pancreas labeled with a calcium ion-sensitive fluorescent dye. In the future, the potential power of plastic FCM is expected to increase, enabling analysis of structure and organization of specific functions in live cells within vulnerable organs.

Test target for characterizing 3D resolution of optical coherence tomography

NASA Astrophysics Data System (ADS)

Hu, Zhixiong; Hao, Bingtao; Liu, Wenli; Hong, Baoyu; Li, Jiao

2014-12-01

Optical coherence tomography (OCT) is a non-invasive 3D imaging technology which has been applied or investigated in many diagnostic fields including ophthalmology, dermatology, dentistry, cardiovasology, endoscopy, brain imaging and so on. Optical resolution is an important characteristic that can describe the quality and utility of an image acquiring system. We employ 3D printing technology to design and fabricate a test target for characterizing 3D resolution of optical coherence tomography. The test target which mimics USAF 1951 test chart was produced with photopolymer. By measuring the 3D test target, axial resolution as well as lateral resolution of a spectral domain OCT system was evaluated. For comparison, conventional microscope and surface profiler were employed to characterize the 3D test targets. The results demonstrate that the 3D resolution test targets have the potential of qualitatively and quantitatively validating the performance of OCT systems.

High-speed, random-access fluorescence microscopy: I. High-resolution optical recording with voltage-sensitive dyes and ion indicators.

PubMed

Bullen, A; Patel, S S; Saggau, P

1997-07-01

The design and implementation of a high-speed, random-access, laser-scanning fluorescence microscope configured to record fast physiological signals from small neuronal structures with high spatiotemporal resolution is presented. The laser-scanning capability of this nonimaging microscope is provided by two orthogonal acousto-optic deflectors under computer control. Each scanning point can be randomly accessed and has a positioning time of 3-5 microseconds. Sampling time is also computer-controlled and can be varied to maximize the signal-to-noise ratio. Acquisition rates up to 200k samples/s at 16-bit digitizing resolution are possible. The spatial resolution of this instrument is determined by the minimal spot size at the level of the preparation (i.e., 2-7 microns). Scanning points are selected interactively from a reference image collected with differential interference contrast optics and a video camera. Frame rates up to 5 kHz are easily attainable. Intrinsic variations in laser light intensity and scanning spot brightness are overcome by an on-line signal-processing scheme. Representative records obtained with this instrument by using voltage-sensitive dyes and calcium indicators demonstrate the ability to make fast, high-fidelity measurements of membrane potential and intracellular calcium at high spatial resolution (2 microns) without any temporal averaging.

High-speed, random-access fluorescence microscopy: I. High-resolution optical recording with voltage-sensitive dyes and ion indicators.

PubMed Central

Bullen, A; Patel, S S; Saggau, P

1997-01-01

The design and implementation of a high-speed, random-access, laser-scanning fluorescence microscope configured to record fast physiological signals from small neuronal structures with high spatiotemporal resolution is presented. The laser-scanning capability of this nonimaging microscope is provided by two orthogonal acousto-optic deflectors under computer control. Each scanning point can be randomly accessed and has a positioning time of 3-5 microseconds. Sampling time is also computer-controlled and can be varied to maximize the signal-to-noise ratio. Acquisition rates up to 200k samples/s at 16-bit digitizing resolution are possible. The spatial resolution of this instrument is determined by the minimal spot size at the level of the preparation (i.e., 2-7 microns). Scanning points are selected interactively from a reference image collected with differential interference contrast optics and a video camera. Frame rates up to 5 kHz are easily attainable. Intrinsic variations in laser light intensity and scanning spot brightness are overcome by an on-line signal-processing scheme. Representative records obtained with this instrument by using voltage-sensitive dyes and calcium indicators demonstrate the ability to make fast, high-fidelity measurements of membrane potential and intracellular calcium at high spatial resolution (2 microns) without any temporal averaging. Images FIGURE 6 PMID:9199810

Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope

PubMed Central

Fukuta, Masahiro; Kanamori, Satoshi; Furukawa, Taichi; Nawa, Yasunori; Inami, Wataru; Lin, Sheng; Kawata, Yoshimasa; Terakawa, Susumu

2015-01-01

Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications. PMID:26525841

Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope.

PubMed

Fukuta, Masahiro; Kanamori, Satoshi; Furukawa, Taichi; Nawa, Yasunori; Inami, Wataru; Lin, Sheng; Kawata, Yoshimasa; Terakawa, Susumu

2015-11-03

Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications.

Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope

NASA Astrophysics Data System (ADS)

Fukuta, Masahiro; Kanamori, Satoshi; Furukawa, Taichi; Nawa, Yasunori; Inami, Wataru; Lin, Sheng; Kawata, Yoshimasa; Terakawa, Susumu

2015-11-01

Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications.

Measurement of the Resolution of the Optical Microscope.

ERIC Educational Resources Information Center

Bowlt, C.

1983-01-01

Outlines procedures demonstrating that the aperture of a microscope objective limits resolving power and then, by using ancillary measurements made with a calibrated graticule in the microscope eyepiece, that the experimentally determined value for the maximum resolving power of a given objective is close to the value predicted by theory. (JN)

Polarization microscopy by use of digital holography: application to optical-fiber birefringence measurements.

PubMed

Colomb, Tristan; Dürr, Florian; Cuche, Etienne; Marquet, Pierre; Limberger, Hans G; Salathé, René-Paul; Depeursinge, Christian

2005-07-20

We present a digital holographic microscope that permits one to image polarization state. This technique results from the coupling of digital holographic microscopy and polarization digital holography. The interference between two orthogonally polarized reference waves and the wave transmitted by a microscopic sample, magnified by a microscope objective, is recorded on a CCD camera. The off-axis geometry permits one to reconstruct separately from this single hologram two wavefronts that are used to image the object-wave Jones vector. We applied this technique to image the birefringence of a bent fiber. To evaluate the precision of the phase-difference measurement, the birefringence induced by internal stress in an optical fiber is measured and compared to the birefringence profile captured by a standard method, which had been developed to obtain high-resolution birefringence profiles of optical fibers.

Hartmann characterization of the PEEM-3 aberration-corrected X-ray photoemission electron microscope.

PubMed

Scholl, A; Marcus, M A; Doran, A; Nasiatka, J R; Young, A T; MacDowell, A A; Streubel, R; Kent, N; Feng, J; Wan, W; Padmore, H A

2018-05-01

Aberration correction by an electron mirror dramatically improves the spatial resolution and transmission of photoemission electron microscopes. We will review the performance of the recently installed aberration corrector of the X-ray Photoemission Electron Microscope PEEM-3 and show a large improvement in the efficiency of the electron optics. Hartmann testing is introduced as a quantitative method to measure the geometrical aberrations of a cathode lens electron microscope. We find that aberration correction leads to an order of magnitude reduction of the spherical aberrations, suggesting that a spatial resolution of below 100 nm is possible at 100% transmission of the optics when using x-rays. We demonstrate this improved performance by imaging test patterns employing element and magnetic contrast. Published by Elsevier B.V.

A colinear backscattering Mueller matrix microscope for reflection Muller matrix imaging

NASA Astrophysics Data System (ADS)

Chen, Zhenhua; Yao, Yue; Zhu, Yuanhuan; Ma, Hui

2018-02-01

In a recent attempt, we developed a colinear backscattering Mueller matrix microscope by adding polarization state generator (PSG) and polarization state analyzer (PSA) into the illumination and detection optical paths of a commercial metallurgical microscope. It is found that specific efforts have to be made to reduce the artifacts due to the intrinsic residual polarizations of the optical system, particularly the dichroism due to the 45 degrees beam splitter. In this paper, we present a new calibration method based on numerical reconstruction of the instrument matrix to remove the artifacts introduced by beam splitter. Preliminary tests using a mirror as a standard sample show that the maximum Muller matrix element error of the colinear backscattering Muller matrix microscope can be reduced to a few percent.

The construction and characterization of optical traps for manipulating microscopic particles

NASA Astrophysics Data System (ADS)

Thompson, Tiffany; Behringer, Ernest

2011-04-01

Optical traps use tightly focused laser light to manipulate microscopic particles and have applications in nanofabrication, characterizing DNA, and in vitro fertilization [1]. We will describe the design, construction, and characterization of an optical trap that is capable of trapping and imaging 3 μm polystyrene spheres using a 12 mW HeNe laser. The design was based on previous work [2,3] describing how to build affordable optical traps. We will discuss trapping forces and their calibration. [4pt] [1] D.G. Grier, "A Revolution in Optical Manipulation," Nature 424, 810-816 (2003). [0pt] [2] S.P. Smith et al., "Inexpensive optical tweezers for undergraduate laboratories," Am. J. Phys. 67 (1), 26-35 (1999).[0pt] [3] J. Bechhoefer et al., "Faster, cheaper, safer optical tweezers for the undergraduate laboratory," Am. J. Phys. 70 (4), 393-400 (2001).

Multi-scale fluorescence imaging of bacterial infections in animal models

NASA Astrophysics Data System (ADS)

Bixler, Joel N.; Kong, Ying; Cirillo, Jeffrey D.; Maitland, Kristen C.

2013-03-01

Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), currently affects roughly one-third of the world's population. Drug resistant strains of Mtb decrease the effectiveness of current therapeutics and demand the development of new antimicrobial therapies. In addition, the current vaccine, Bacille Calmette Guérin (BCG), has variable efficacy for disease prevention in different populations. Animal studies are often limited by the need to sacrifice at discrete time points for pathology and tissue homogenization, which greatly reduces spatial and temporal resolution. Optical imaging offers the potential for a minimally-invasive solution to imaging on a macroscopic and microscopic scale, allowing for high resolution study of infection. We have integrated a fluorescence microendoscope into a whole-animal optical imaging system, allowing for simultaneous microscopic and macroscopic imaging of tdTomato expressing BCG in vivo. A 535 nm LED was collimated and launched into a 10,000 element fiber bundle with an outer diameter of 0.66 mm. The fiber bundle can be inserted through an intra-tracheal catheter into the lung of a mouse. Fluorescence emission can either be (1) collected by the bundle and imaged onto the surface of a CCD camera for localized detection or (2) the fluorescence can be imaged by the whole animal imaging system providing macroscopic information. Results from internal localized excitation and external whole body detection indicate the potential for imaging bacterial infections down to 100 colony forming units. This novel imaging technique has the potential to allow for functional studies, enhancing the ability to assess new therapeutic agents.

Ultrathin Au film on polymer surface for surface plasmon polariton waveguide application

NASA Astrophysics Data System (ADS)

Liu, Tong; Ji, Lanting; He, Guobing; Sun, Xiaoqiang; Wang, Fei; Zhang, Daming

2017-11-01

Formation of laterally continuous ultrathin gold films on polymer substrates is a technological challenge. In this work, the vacuum thermal evaporation method is adopted to form continuous Au films in the thickness range of 7-17 nm on polymers of Poly(methyl-methacrylate-glycidly-methacrylate) and SU-8 film surface without using the adhesion or metallic seeding layers. Absorption spectrum, scanning electron microscope and atomic force microscope images are used to characterize the Au film thickness, roughness and optical loss. The result shows that molecular-scale structure, surface energy and electronegativity have impacts on the Au film morphology on polymers. Wet chemical etching is used to fabricate 7-nm thick Au stripes embedded in polymer claddings. These long-range surface plasmon polariton waveguides demonstrate the favorable morphological configurations and cross-sectional states. Through the end-fire excitation method, propagation losses of 6-μm wide Au stripes are compared to theoretical values and analyzed from practical film status. The smooth, patternable gold films on polymer provide potential applications to plasmonic waveguides, biosensing, metamaterials and optical antennas.

Two-way communication with neural networks in vivo using focused light

PubMed Central

Wilson, Nathan R.; Schummers, James; Runyan, Caroline A.; Yan, Sherry; Chen, Robert F.; Deng, Yuting; Sur, Mriganka

2014-01-01

Neuronal networks process information in a distributed, spatially heterogeneous fashion that transcends the layout of electrodes. In contrast, directed and steerable light offers the potential to engage specific cells on demand. We present a unified framework for adapting microscopes to use light for simultaneous in vivo stimulation and recording of cells at fine spatiotemporal resolutions. We utilize straightforward optics to lock onto networks in vivo, steer light to activate circuit elements, and simultaneously record from other cells. We then actualize this “free” augmentation on both an “open” two-photon microscope, and a leading commercial one. Following this protocol, setup of the system takes a few days and the result is a non-invasive interface to brain dynamics based on directed light, at a network resolution that was not previously possible and which will further improve with the rapid advance in development of optical reporters and effectors. This protocol is for physiologists who are competent with computers and wish to extend hardware and software to interface more fluidly with neuronal networks. PMID:23702834

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosch, R.; Trosseille, C.; Caillaud, T.

The Laser Megajoule (LMJ) facility located at CEA/CESTA started to operate in the early 2014 with two quadruplets (20 kJ at 351 nm) focused on target for the first experimental campaign. We present here the first set of gated x-ray imaging (GXI) diagnostics implemented on LMJ since mid-2014. This set consists of two imaging diagnostics with spatial, temporal, and broadband spectral resolution. These diagnostics will give basic measurements, during the entire life of the facility, such as position, structure, and balance of beams, but they will also be used to characterize gas filled target implosion symmetry and timing, to studymore » x-ray radiography and hydrodynamic instabilities. The design requires a vulnerability approach, because components will operate in a harsh environment induced by neutron fluxes, gamma rays, debris, and shrapnel. Grazing incidence x-ray microscopes are fielded as far as possible away from the target to minimize potential damage and signal noise due to these sources. These imaging diagnostics incorporate microscopes with large source-to-optic distance and large size gated microchannel plate detectors. Microscopes include optics with grazing incidence mirrors, pinholes, and refractive lenses. Spatial, temporal, and spectral performances have been measured on x-ray tubes and UV lasers at CEA-DIF and at Physikalisch-Technische Bundesanstalt BESSY II synchrotron prior to be set on LMJ. GXI-1 and GXI-2 designs, metrology, and first experiments on LMJ are presented here.« less

A multimodal imaging platform with integrated simultaneous photoacoustic microscopy, optical coherence tomography, optical Doppler tomography and fluorescence microscopy

NASA Astrophysics Data System (ADS)

Dadkhah, Arash; Zhou, Jun; Yeasmin, Nusrat; Jiao, Shuliang

2018-02-01

Various optical imaging modalities with different optical contrast mechanisms have been developed over the past years. Although most of these imaging techniques are being used in many biomedical applications and researches, integration of these techniques will allow researchers to reach the full potential of these technologies. Nevertheless, combining different imaging techniques is always challenging due to the difference in optical and hardware requirements for different imaging systems. Here, we developed a multimodal optical imaging system with the capability of providing comprehensive structural, functional and molecular information of living tissue in micrometer scale. This imaging system integrates photoacoustic microscopy (PAM), optical coherence tomography (OCT), optical Doppler tomography (ODT) and fluorescence microscopy in one platform. Optical-resolution PAM (OR-PAM) provides absorption-based imaging of biological tissues. Spectral domain OCT is able to provide structural information based on the scattering property of biological sample with no need for exogenous contrast agents. In addition, ODT is a functional extension of OCT with the capability of measurement and visualization of blood flow based on the Doppler effect. Fluorescence microscopy allows to reveal molecular information of biological tissue using autofluoresce or exogenous fluorophores. In-vivo as well as ex-vivo imaging studies demonstrated the capability of our multimodal imaging system to provide comprehensive microscopic information on biological tissues. Integrating all the aforementioned imaging modalities for simultaneous multimodal imaging has promising potential for preclinical research and clinical practice in the near future.

Integrated Micro-Optics for Microfluidic Detection.

PubMed

Kazama, Yuto; Hibara, Akihide

2016-01-01

A method of embedding micro-optics into a microfluidic device was proposed and demonstrated. First, the usefulness of embedded right-angle prisms was demonstrated in microscope observation. Lateral-view microscopic observation of an aqueous dye flow in a 100-μm-sized microchannel was demonstrated. Then, the embedded right-angle prisms were utilized for multi-beam laser spectroscopy. Here, crossed-beam thermal lens detection of a liquid sample was applied to glucose detection.

Optical Interferometric Micrometrology

NASA Technical Reports Server (NTRS)

Abel, Phillip B.; Lauer, James R.

1989-01-01

Resolutions in angstrom and subangstrom range sought for atomic-scale surface probes. Experimental optical micrometrological system built to demonstrate calibration of piezoelectric transducer to displacement sensitivity of few angstroms. Objective to develop relatively simple system producing and measuring translation, across surface of specimen, of stylus in atomic-force or scanning tunneling microscope. Laser interferometer used to calibrate piezoelectric transducer used in atomic-force microscope. Electronic portion of calibration system made of commercially available components.

Dual-modal three-dimensional imaging of single cells with isometric high resolution using an optical projection tomography microscope

NASA Astrophysics Data System (ADS)

Miao, Qin; Rahn, J. Richard; Tourovskaia, Anna; Meyer, Michael G.; Neumann, Thomas; Nelson, Alan C.; Seibel, Eric J.

2009-11-01

The practice of clinical cytology relies on bright-field microscopy using absorption dyes like hematoxylin and eosin in the transmission mode, while the practice of research microscopy relies on fluorescence microscopy in the epi-illumination mode. The optical projection tomography microscope is an optical microscope that can generate 3-D images of single cells with isometric high resolution both in absorption and fluorescence mode. Although the depth of field of the microscope objective is in the submicron range, it can be extended by scanning the objective's focal plane. The extended depth of field image is similar to a projection in a conventional x-ray computed tomography. Cells suspended in optical gel flow through a custom-designed microcapillary. Multiple pseudoprojection images are taken by rotating the microcapillary. After these pseudoprojection images are further aligned, computed tomography methods are applied to create 3-D reconstruction. 3-D reconstructed images of single cells are shown in both absorption and fluorescence mode. Fluorescence spatial resolution is measured at 0.35 μm in both axial and lateral dimensions. Since fluorescence and absorption images are taken in two different rotations, mechanical error may cause misalignment of 3-D images. This mechanical error is estimated to be within the resolution of the system.

Noise induced chaos in optically driven colloidal rings.

NASA Astrophysics Data System (ADS)

Roichman, Yael; Zaslavsky, George; Grier, David G.

2007-03-01

Given a constant flux of energy, many driven dissipative systems rapidly organize themselves into configurations that support steady state motion. Examples include swarming of bacterial colonies, convection in shaken sandpiles, and synchronization in flowing traffic. How simple objects interacting in simple ways self-organize generally is not understood, mainly because so few of the available experimental systems afford the necessary access to their microscopic degrees of freedom. This talk introduces a new class of model driven dissipative systems typified by three colloidal spheres circulating around a ring-like optical trap known as an optical vortex. By controlling the interplay between hydrodynamic interactions and fixed disorder we are able to drive a transition from a previously predicted periodic steady state to fully developed chaos. In addition, by tracking both microscopic trajectories and macroscopic collective fluctuations the relation between the onset of microscopic weak chaos and the evolution of space-time self-similarity in macroscopic transport properties is revealed. In a broader scope, several optical vortices can be coupled to create a large dissipative system where each building block has internal degrees of freedom. In such systems the little understood dynamics of processes like frustration and jamming, fluctuation-dissipation relations and the propagation of collective motion can be tracked microscopically.

Superhydrophobic, Biomimetic Surfaces with High and Low Adhesion, Optical Transmittance, and Nanoscale Mechanical Wear Resistance

NASA Astrophysics Data System (ADS)

Ebert, Daniel R.

Superhydrophobic surfaces (defined as surfaces having water contact angle greater than 150°) show great promise for use in a rapidly growing number of engineering applications, ranging from biomedical devices to fluid drag reduction in pipelines. In nature, the surfaces of many organisms, such as certain plant leaves, are known to exhibit superhydrophobicity. In some cases, droplet adhesion is very low (droplet rolls away easily), while in other cases adhesion is high (droplet remains adhered when surface is inverted). The recent advent and development of microscopes with resolution down to a few nanometers (such as atomic force microscopes and scanning electron microscopes) has allowed for in-depth understanding of the micro- and nanoscale mechanisms employed by these plant leaves and other natural surfaces to achieve their particular wetting properties. Biomimetics (or "mimicking nature") is therefore a very promising approach for the development of engineering surfaces with desired wetting characteristics. However, research in creating biomimetic surfaces is still in its early stages, and many of the surfaces created thus far are not mechanically robust, which is required for many potential real-world applications. In addition, for applications such as self-cleaning windows and solar panels, optical transparency is required. In this thesis, a set of original studies are presented in which superhydrophobic surfaces were designed based on biomimetics and fabricated using a wide of variety of techniques. The surfaces were characterized with regard to wetting characteristics such as water contact angle and contact angle hysteresis, micro- and nanoscale mechanical durability, and in some cases optical transmittance. Theoretical wetting models served as guides both in the design and in the understanding of experimental results, especially in regard to different wetting regime and regime transition. This work provides important conclusions and valuable insight for identifying materials, techniques, and designs for mechanically durable, optically transparent superhydrophobic surfaces.

Aqueous carrier waveguide in a flow cytometer

DOEpatents

Mariella, R.P. Jr.; Engh, G. van den; Northrup, M.A.

1995-12-12

The liquid of a flow cytometer itself acts as an optical waveguide, thus transmitting the light to an optical filter/detector combination. This alternative apparatus and method for detecting scattered light in a flow cytometer is provided by a device which views and detects the light trapped within the optical waveguide formed by the flow stream. A fiber optic or other light collecting device is positioned within the flow stream. This provides enormous advantages over the standard light collection technique which uses a microscope objective. The signal-to-noise ratio is greatly increased over that for right-angle-scattered light collected by a microscope objective, and the alignment requirements are simplified. 6 figs.

Reliable measurement of E. coli single cell fluorescence distribution using a standard microscope set-up.

PubMed

Cortesi, Marilisa; Bandiera, Lucia; Pasini, Alice; Bevilacqua, Alessandro; Gherardi, Alessandro; Furini, Simone; Giordano, Emanuele

2017-01-01

Quantifying gene expression at single cell level is fundamental for the complete characterization of synthetic gene circuits, due to the significant impact of noise and inter-cellular variability on the system's functionality. Commercial set-ups that allow the acquisition of fluorescent signal at single cell level (flow cytometers or quantitative microscopes) are expensive apparatuses that are hardly affordable by small laboratories. A protocol that makes a standard optical microscope able to acquire quantitative, single cell, fluorescent data from a bacterial population transformed with synthetic gene circuitry is presented. Single cell fluorescence values, acquired with a microscope set-up and processed with custom-made software, are compared with results that were obtained with a flow cytometer in a bacterial population transformed with the same gene circuitry. The high correlation between data from the two experimental set-ups, with a correlation coefficient computed over the tested dynamic range > 0.99, proves that a standard optical microscope- when coupled with appropriate software for image processing- might be used for quantitative single-cell fluorescence measurements. The calibration of the set-up, together with its validation, is described. The experimental protocol described in this paper makes quantitative measurement of single cell fluorescence accessible to laboratories equipped with standard optical microscope set-ups. Our method allows for an affordable measurement/quantification of intercellular variability, whose better understanding of this phenomenon will improve our comprehension of cellular behaviors and the design of synthetic gene circuits. All the required software is freely available to the synthetic biology community (MUSIQ Microscope flUorescence SIngle cell Quantification).

Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues.

PubMed

Sung, Kung-Bin; Liang, Chen; Descour, Michael; Collier, Tom; Follen, Michele; Richards-Kortum, Rebecca

2002-10-01

We have built a fiber-optic confocal reflectance microscope capable of imaging human tissues in near real time. Miniaturization of the objective lens and the mechanical components for positioning and axially scanning the objective enables the device to be used in inner organs of the human body. The lateral resolution is 2 micrometers and axial resolution is 10 micrometers. Confocal images of fixed tissue biopsies and the human lip in vivo have been obtained at 15 frames/s without any fluorescent stains. Both cell morphology and tissue architecture can be appreciated from images obtained with this microscope.

A lab-on-phone instrument with varifocal microscope via a liquid-actuated aspheric lens (LAL)

PubMed Central

Fuh, Yiin-Kuen; Lai, Zheng-Hong; Kau, Li-Han; Huang, Hung-Jui

2017-01-01

In this paper, we introduce a novel concept of liquid-actuated aspheric lens (LAL) with a built-in aspheric polydimethylsiloxane lens (APL) to enable the design of compact optical systems with varifocal microscopic imaging. The varifocal lens module consists of a sandwiched structures such as 3d printed syringe pump functionally serves as liquid controller. Other key components include two acrylic cylinders, a rigid separator, a APL/membrane composite (APLMC) embedded PDMS membrane. In functional operation, the fluidic controller was driven to control the pressure difference and ALPMC deformation. The focal length can be changed through the pressure difference. This is achieved by the adjustment of volume change of injected liquid such that a widely tunable focal length. The proposed LAL can transform to 3 modes: microscopic mode (APLMC only), convex-concave mode and biconcave mode. It is noticeable that LAL in the operation of microscopic mode is tunable in focus via the actuation of APLMC (focal length is from 4.3 to 2.3 mm and magnification 50X) and can rival the images quality of commercial microscopes. A new lab-on-phone device is economically feasible and functionally versatile to offer a great potential in the point of care applications. PMID:28650971

Surface slope metrology of highly curved x-ray optics with an interferometric microscope

NASA Astrophysics Data System (ADS)

Gevorkyan, Gevork S.; Centers, Gary; Polonska, Kateryna S.; Nikitin, Sergey M.; Lacey, Ian; Yashchuk, Valeriy V.

2017-09-01

The development of deterministic polishing techniques has given rise to vendors that manufacture high quality threedimensional x-ray optics. The surface metrology on these optics remains a difficult task. For the fabrication, vendors usually use unique surface metrology tools, generally developed on site, that are not available in the optical metrology labs at x-ray facilities. At the Advanced Light Source X-Ray Optics Laboratory, we have developed a rather straightforward interferometric-microscopy-based procedure capable of sub microradian characterization of sagittal slope variation of x-ray optics for two-dimensionally focusing and collimating (such as ellipsoids, paraboloids, etc.). In the paper, we provide the mathematical foundation of the procedure and describe the related instrument calibration. We also present analytical expression describing the ideal surface shape in the sagittal direction of a spheroid specified by the conjugate parameters of the optic's beamline application. The expression is useful when analyzing data obtained with such optics. The high efficiency of the developed measurement and data analysis procedures is demonstrated in results of measurements with a number of x-ray optics with sagittal radius of curvature between 56 mm and 480 mm. We also discuss potential areas of further improvement.

Real-Time Nanoscopy by Using Blinking Enhanced Quantum Dots

PubMed Central

Watanabe, Tomonobu M.; Fukui, Shingo; Jin, Takashi; Fujii, Fumihiko; Yanagida, Toshio

2010-01-01

Superresolution optical microscopy (nanoscopy) is of current interest in many biological fields. Superresolution optical fluctuation imaging, which utilizes higher-order cumulant of fluorescence temporal fluctuations, is an excellent method for nanoscopy, as it requires neither complicated optics nor illuminations. However, it does need an impractical number of images for real-time observation. Here, we achieved real-time nanoscopy by modifying superresolution optical fluctuation imaging and enhancing the fluctuation of quantum dots. Our developed quantum dots have higher blinking than commercially available ones. The fluctuation of the blinking improved the resolution when using a variance calculation for each pixel instead of a cumulant calculation. This enabled us to obtain microscopic images with 90-nm and 80-ms spatial-temporal resolution by using a conventional fluorescence microscope without any optics or devices. PMID:20923631

Self-referenced axial chromatic dispersion measurement in multiphoton microscopy through 2-color THG imaging.

PubMed

Du, Yu; Zhuang, Ziwei; He, Jiexing; Liu, Hongji; Qiu, Ping; Wang, Ke

2018-05-16

With tunable excitation light, multiphoton microscopy (MPM) is widely used for imaging biological structures at subcellular resolution. Axial chromatic dispersion, present in virtually every transmissive optical system including the multiphoton microscope, leads to focal (and the resultant image) plane separation. Here we demonstrate experimentally a technique to measure the axial chromatic dispersion in a multiphoton microscope, using simultaneous 2-color third-harmonic generation (THG) imaging excited by a 2-color soliton source with tunable wavelength separation. Our technique is self-referenced, eliminating potential measurement error when 1-color tunable excitation light is used which necessitates reciprocating motion of the mechanical translation stage. Using this technique, we demonstrate measured axial chromatic dispersion with 2 different objective lenses in a multiphoton microscope. Further measurement in a biological sample also indicates that this axial chromatic dispersion, in combination with 2-color imaging, may open up opportunity for simultaneous imaging of two different axial planes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Two-probe atomic-force microscope manipulator and its applications.

PubMed

Zhukov, A A; Stolyarov, V S; Kononenko, O V

2017-06-01

We report on a manipulator based on a two-probe atomic force microscope (AFM) with an individual feedback system for each probe. This manipulator works under an upright optical microscope with 3 mm focal distance. The design of the microscope helps us tomanipulate nanowires using the microscope probes as a two-prong fork. The AFM feedback is realized based on the dynamic full-time contact mode. The applications of the manipulator and advantages of its two-probe design are presented.

SIL-STED microscopy technique enhancing super-resolution of fluorescence microscopy

NASA Astrophysics Data System (ADS)

Park, No-Cheol; Lim, Geon; Lee, Won-sup; Moon, Hyungbae; Choi, Guk-Jong; Park, Young-Pil

2017-08-01

We have characterized a new type STED microscope which combines a high numerical aperture (NA) optical head with a solid immersion lens (SIL), and we call it as SIL-STED microscope. The advantage of a SIL-STED microscope is that its high NA of the SIL makes it superior to a general STED microscope in lateral resolution, thus overcoming the optical diffraction limit at the macromolecular level and enabling advanced super-resolution imaging of cell surface or cell membrane structure and function Do. This study presents the first implementation of higher NA illumination in a STED microscope limiting the fluorescence lateral resolution to about 40 nm. The refractive index of the SIL which is made of material KTaO3 is about 2.23 and 2.20 at a wavelength of 633 nm and 780 nm which are used for excitation and depletion in STED imaging, respectively. Based on the vector diffraction theory, the electric field focused by the SILSTED microscope is numerically calculated so that the numerical results of the point dispersion function of the microscope and the expected resolution could be analyzed. For further investigation, fluorescence imaging of nano size fluorescent beads is fulfilled to show improved performance of the technique.

Comprehensive optical and data management infrastructure for high-throughput light-sheet microscopy of whole mouse brains.

PubMed

Müllenbroich, M Caroline; Silvestri, Ludovico; Onofri, Leonardo; Costantini, Irene; Hoff, Marcel Van't; Sacconi, Leonardo; Iannello, Giulio; Pavone, Francesco S

2015-10-01

Comprehensive mapping and quantification of neuronal projections in the central nervous system requires high-throughput imaging of large volumes with microscopic resolution. To this end, we have developed a confocal light-sheet microscope that has been optimized for three-dimensional (3-D) imaging of structurally intact clarified whole-mount mouse brains. We describe the optical and electromechanical arrangement of the microscope and give details on the organization of the microscope management software. The software orchestrates all components of the microscope, coordinates critical timing and synchronization, and has been written in a versatile and modular structure using the LabVIEW language. It can easily be adapted and integrated to other microscope systems and has been made freely available to the light-sheet community. The tremendous amount of data routinely generated by light-sheet microscopy further requires novel strategies for data handling and storage. To complete the full imaging pipeline of our high-throughput microscope, we further elaborate on big data management from streaming of raw images up to stitching of 3-D datasets. The mesoscale neuroanatomy imaged at micron-scale resolution in those datasets allows characterization and quantification of neuronal projections in unsectioned mouse brains.

The contributions of Otto Scherzer (1909-1982) to the development of the electron microscope.

PubMed

Marko, Michael; Rose, Harald

2010-08-01

Otto Scherzer was one of the pioneers of theoretical electron optics. He was coauthor of the first comprehensive book on electron optics and was the first to understand that round electron lenses could not be combined to correct aberrations, as is the case in light optics. He subsequently was the first to describe several alternative means to correct spherical and chromatic aberration of electron lenses. These ideas were put into practice by his laboratory and students at Darmstadt and their successors, leading to the fully corrected electron microscopes now in operation.

Development of Nomarski microscopy for quantitative determination of surface topography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartman, J. S.; Gordon, R. L.; Lessor, D. L.

1979-01-01

The use of Nomarski differential interference contrast (DIC) microscopy has been extended to provide nondestructive, quantitative analysis of a sample's surface topography. Theoretical modeling has determined the dependence of the image intensity on the microscope's optical components, the sample's optical properties, and the sample's surface orientation relative to the microscope. Results include expressions to allow the inversion of image intensity data to determine sample surface slopes. A commercial Nomarski system has been modified and characterized to allow the evaluation of the optical model. Data have been recorded with smooth, planar samples that verify the theoretical predictions.

Remote Histology Learning from Static versus Dynamic Microscopic Images

ERIC Educational Resources Information Center

Mione, Sylvia; Valcke, Martin; Cornelissen, Maria

2016-01-01

Histology is the study of microscopic structures in normal tissue sections. Curriculum redesign in medicine has led to a decrease in the use of optical microscopes during practical classes. Other imaging solutions have been implemented to facilitate remote learning. With advancements in imaging technologies, learning material can now be digitized.…

Optimal resolution in Fresnel incoherent correlation holographic fluorescence microscopy

PubMed Central

Brooker, Gary; Siegel, Nisan; Wang, Victor; Rosen, Joseph

2011-01-01

Fresnel Incoherent Correlation Holography (FINCH) enables holograms and 3D images to be created from incoherent light with just a camera and spatial light modulator (SLM). We previously described its application to microscopic incoherent fluorescence wherein one complex hologram contains all the 3D information in the microscope field, obviating the need for scanning or serial sectioning. We now report experiments which have led to the optimal optical, electro-optic, and computational conditions necessary to produce holograms which yield high quality 3D images from fluorescent microscopic specimens. An important improvement from our previous FINCH configurations capitalizes on the polarization sensitivity of the SLM so that the same SLM pixels which create the spherical wave simulating the microscope tube lens, also pass the plane waves from the infinity corrected microscope objective, so that interference between the two wave types at the camera creates a hologram. This advance dramatically improves the resolution of the FINCH system. Results from imaging a fluorescent USAF pattern and a pollen grain slide reveal resolution which approaches the Rayleigh limit by this simple method for 3D fluorescent microscopic imaging. PMID:21445140

Analysis of {sup 4}He+{sup 40}Ca and {sup 4}He+{sup 44}Ti scattering using different optical model potentials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ibraheem, Awad A., E-mail: awad-ah-eb@hotmail.com

Elastic scattering of {sup 4}He+{sup 40}Ca and {sup 4}He+{sup 44}Ti reactions at backward angles has been analyzed using two different models, microscopic and semimicroscopic folding potentials. The derived real potentials supplemented with phenomenological Woods–Saxon imaginary potentials, provide good agreement with the experimental data at energy E{sub c.m.} = 21.8 MeV without need to renormalize the potentials. Coupled channels calculations are used to extract the inelastic scattering cross section to the low-lying state 2+ (1.083 MeV) of {sup 44}Ti. The deformation length is obtained and compared with the electromagnetic measurement values as well as those obtained from previous studies.

Generation and spectroscopic signatures of a fractional quantum Hall liquid of photons in an incoherently pumped optical cavity

NASA Astrophysics Data System (ADS)

Umucalılar, R. O.; Carusotto, I.

2017-11-01

We investigate theoretically a driven dissipative model of strongly interacting photons in a nonlinear optical cavity in the presence of a synthetic magnetic field. We show the possibility of using a frequency-dependent incoherent pump to create a strongly correlated ν =1 /2 bosonic Laughlin state of light: Due to the incompressibility of the Laughlin state, fluctuations in the total particle number and excitation of edge modes can be tamed by imposing a suitable external potential profile for photons. We further propose angular-momentum-selective spectroscopy of the emitted light as a tool to obtain unambiguous signatures of the microscopic physics of the quantum Hall liquid of light.

Measurement of Fluorescence in a Rhodamine-123 Doped Self-Assembled “Giant” Mesostructured Silica Sphere Using a Smartphone as Optical Hardware

PubMed Central

Canning, John; Lau, Angelica; Naqshbandi, Masood; Petermann, Ingemar; Crossley, Maxwell J.

2011-01-01

The blue OLED emission from a mobile phone was characterised, revealing a sharp emission band centred at λ = 445 nm with a 3dB bandwidth Δλ ∼ 20 nm. It was used to excite Rhodamine 123 doped within a “giant” mesostructured silica sphere during fabrication through evaporative self-assembly of silica nanoparticles. Fluorescence was able to be detected using a standard optical microscope fitted with a green transmission pass filter and cooled CCD and with 1 ms exposure time demonstrating the potential of mobile platforms as the basis for portable diagnostics in the field. PMID:22164002

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henn, T.; Kiessling, T., E-mail: tobias.kiessling@physik.uni-wuerzburg.de; Ossau, W.

We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast “white light” supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables themore » investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.« less

Analysis system of submicron particle tracks in the fine-grained nuclear emulsion by a combination of hard x-ray and optical microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naka, T., E-mail: naka@flab.phys.nagoya-u.ac.jp; Institute for Advanced Research, Nagoya University, Aichi 464-8602; Asada, T.

Analyses of nuclear emulsion detectors that can detect and identify charged particles or radiation as tracks have typically utilized optical microscope systems because the targets have lengths from several μm to more than 1000 μm. For recent new nuclear emulsion detectors that can detect tracks of submicron length or less, the current readout systems are insufficient due to their poor resolution. In this study, we developed a new system and method using an optical microscope system for rough candidate selection and the hard X-ray microscope system at SPring-8 for high-precision analysis with a resolution of better than 70 nm resolution.more » Furthermore, we demonstrated the analysis of submicron-length tracks with a matching efficiency of more than 99% and position accuracy of better than 5 μm. This system is now running semi-automatically.« less

Fractal evaluation of drug amorphicity from optical and scanning electron microscope images

NASA Astrophysics Data System (ADS)

Gavriloaia, Bogdan-Mihai G.; Vizireanu, Radu C.; Neamtu, Catalin I.; Gavriloaia, Gheorghe V.

2013-09-01

Amorphous materials are metastable, more reactive than the crystalline ones, and have to be evaluated before pharmaceutical compound formulation. Amorphicity is interpreted as a spatial chaos, and patterns of molecular aggregates of dexamethasone, D, were investigated in this paper by using fractal dimension, FD. Images having three magnifications of D were taken from an optical microscope, OM, and with eight magnifications, from a scanning electron microscope, SEM, were analyzed. The average FD for pattern irregularities of OM images was 1.538, and about 1.692 for SEM images. The FDs of the two kinds of images are less sensitive of threshold level. 3D images were shown to illustrate dependence of FD of threshold and magnification level. As a result, optical image of single scale is enough to characterize the drug amorphicity. As a result, the OM image at a single scale is enough to characterize the amorphicity of D.

Failure Analysis of Heavy-Ion-Irradiated Schottky Diodes

NASA Technical Reports Server (NTRS)

Casey, Megan C.; Lauenstein, Jean-Marie; Wilcox, Edward P.; Topper, Alyson D.; Campola, Michael J.; Label, Kenneth A.

2017-01-01

In this work, we use high- and low-magnitude optical microscope images, infrared camera images, and scanning electron microscope images to identify and describe the failure locations in heavy-ion-irradiated Schottky diodes.

Enhancing the performance of the light field microscope using wavefront coding

PubMed Central

Cohen, Noy; Yang, Samuel; Andalman, Aaron; Broxton, Michael; Grosenick, Logan; Deisseroth, Karl; Horowitz, Mark; Levoy, Marc

2014-01-01

Light field microscopy has been proposed as a new high-speed volumetric computational imaging method that enables reconstruction of 3-D volumes from captured projections of the 4-D light field. Recently, a detailed physical optics model of the light field microscope has been derived, which led to the development of a deconvolution algorithm that reconstructs 3-D volumes with high spatial resolution. However, the spatial resolution of the reconstructions has been shown to be non-uniform across depth, with some z planes showing high resolution and others, particularly at the center of the imaged volume, showing very low resolution. In this paper, we enhance the performance of the light field microscope using wavefront coding techniques. By including phase masks in the optical path of the microscope we are able to address this non-uniform resolution limitation. We have also found that superior control over the performance of the light field microscope can be achieved by using two phase masks rather than one, placed at the objective’s back focal plane and at the microscope’s native image plane. We present an extended optical model for our wavefront coded light field microscope and develop a performance metric based on Fisher information, which we use to choose adequate phase masks parameters. We validate our approach using both simulated data and experimental resolution measurements of a USAF 1951 resolution target; and demonstrate the utility for biological applications with in vivo volumetric calcium imaging of larval zebrafish brain. PMID:25322056

The effect of mechanical drawing on optical and structural properties of nylon 6 fibres

NASA Astrophysics Data System (ADS)

El-Bakary, M. A.

2007-09-01

The Pluta polarizing double-refracting interference microscope was attached to a mechanical drawing device to study the effect of cold drawing on the optical and structural properties of nylon 6 fibres. The microscope was used in its two positions for determining the refractive indices and birefringence of fibres. Different applied stresses and strain rates were obtained using the mechanical-drawing device. The effect of the applied stresses on the optical and physical parameters was investigated. The resulting optical parameters were utilized to investigate the polarizability per unit volume, the optical orientation factor, the orientation angle and the average work per chain. The refractive index and birefringence profiles were measured. Relationships between the average work per chain and optical parameters at different strains rates were determined. An empirical formula was deduced for these fibres. Micro-interferograms are given for illustration.

Spatiotemporal polarization modulation microscopy with a microretarder array

NASA Astrophysics Data System (ADS)

Ding, Changqin; Ulcickas, James R. W.; Simpson, Garth J.

2018-02-01

A patterned microretarder array positioned in the rear conjugate plane of a microscope enables rapid polarizationdependent nonlinear optical microscopy. The pattern introduced to the array results in periodic modulation of the polarization-state of the incident light as a function of position within the field of view with no moving parts or active control. Introduction of a single stationary optical element and a fixed polarizer into the beam of a nonlinear optical microscope enabled nonlinear optical tensor recovery, which informs on local structure and orientation. Excellent agreement was observed between the measured and predicted second harmonic generation (SHG) of z-cut quartz, selected as a test system with well-established nonlinear optical properties. Subsequent studies of spatially varying samples further support the general applicability of this relatively simple strategy for detailed polarization analysis in both conventional and nonlinear optical imaging of structurally diverse samples.

Highly sensitive optical detection of specific protein in breast cancer cells using microstructured fiber in extremely low sample volume

NASA Astrophysics Data System (ADS)

Padmanabhan, Saraswathi; Shinoj, Vengalathunadakal K.; Murukeshan, Vadakke M.; Padmanabhan, Parasuraman

2010-01-01

A simple optical method using hollow-core photonic crystal fiber for protein detection has been described. In this study, estrogen receptor (ER) from a MCF-7 breast carcinoma cell lysates immobilized inside a hollow-core photonic crystal fiber was detected using anti-ER primary antibody with either Alexa™ Fluor 488 (green fluorescent dye) or 555 (red Fluorescent dye) labeled Goat anti-rabbit IgG as the secondary antibody. The fluorescence fingerprints of the ERα protein were observed under fluorescence microscope, and its optical characteristics were analyzed. The ERα protein detection by this proposed method is based on immuno binding from sample volume as low as 50 nL. This method is expected to offer great potential as a biosensor for medical diagnostics and therapeutics applications.

Laser-assisted marking for toric intraocular lens alignment.

PubMed

Dick, H Burkhard; Schultz, Tim

2016-01-01

We describe a technique of 3-dimensional spectral-domain optical coherence tomography-controlled laser-assisted corneal marking for toric intraocular lens implantation. To facilitate accurate alignment, the technique creates 2 perpendicular intrastromal incisions (width 0.75 mm) using an image-guided femtosecond laser. This was performed in a case series comprising 10 eyes of 10 patients. No posterior corneal perforation or epithelial alterations occurred. The incisions were plainly visible under the operating microscope, and no optical phenomena were reported 6 weeks after surgery. Laser-assisted marking can be performed safely and has the potential to enable precise axis marking. Dr. Dick is a paid consultant to Abbott Medical Optics, Inc. Dr. Schultz has no financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Effect of etching time on morphological, optical, and electronic properties of silicon nanowires

PubMed Central

2012-01-01

Owing to their interesting electronic, mechanical, optical, and transport properties, silicon nanowires (SiNWs) have attracted much attention, giving opportunities to several potential applications in nanoscale electronic, optoelectronic devices, and silicon solar cells. For photovoltaic application, a superficial film of SiNWs could be used as an efficient antireflection coating. In this work we investigate the morphological, optical, and electronic properties of SiNWs fabricated at different etching times. Characterizations of the formed SiNWs films were performed using a scanning electron microscope, ultraviolet–visible-near-infrared spectroscopy, and light-beam-induced-current technique. The latter technique was used to determine the effective diffusion length in SiNWs films. From these investigations, we deduce that the homogeneity of the SiNWs film plays a key role on the electronic properties. PMID:22799265

Optical and Acoustical Techniques for Non-viral Gene Delivery to Mammalian Cells and In-situ Study of Cytoskeletal Mechanics

NASA Astrophysics Data System (ADS)

Ma, Zili

Since the first optical microscope invented by Anton van Leeuwenhoek in 1674, the great development of laser technique and its applications in biophotonics have helped us reveal the mechanisms underlying numerous biological activities gradually. The introduction of fs lasers to the studies of biology has emerged as a fast developing area calling for the efforts and skills both from optics and electric engineering and biology and medicine. Due to the fast update of laser source techniques, there has been an increasing number of commercialized fs lasers available for this growing market of biophotonics. To better utilize the potential offered by fs lasers, we studied the technique of optical gene delivery and tried to narrow the gap between laboratorial research and industrial/clinical applications, in that the strict experimental conditions of specific optical laboratorial studies are generally not appropriate for the practical biological applications. To carry out our experiments, we built a two-stage amplifier fs laser system to generate the desired pulse train. The laser pulse train was coupled into an invert fluorescence microscope for the imaging and manipulation of each cell. To overcome limitations brought by the tight focus of laser beam due to high NA objective, we introduced gold nanorods (GNRs), a metallic nanomaterial, with tunable optical property. With these additional membrane for membrane permeabilization, which could significantly improve the manipulation speed than that based on the tightly focused laser. We used GFP plasmid to demonstrate the applications of this technique in gene delivery, and successfully transfected and GFP-expressed cells were observed one day after the optical transfection. Additionally, as an important trend of biophotonics, the integration of optics with microfluidic chips has become the new frontier of both biology and engineering. Here we firstly demonstrated a technique of gene delivery by an on-chip device generating surface acoustic waves, which not only achieved a high efficiency of cells permeabilization in a quick speed, but also allowed us to observe the permeabilization process in real time by microscope. This device is also compatible with biophotonics studies based on fs laser, which can be further developed as a powerful tool for optical gene delivery with the capability of precisely controlling the fluid on-chip by SAW. SAW devices could also achieve exogenous gene delivery through the cell membrane without the need of adding chemical agents. Our results showed that the membrane of mammalian adherent cells could be effectively perforated transiently by applying a SAW. The transfection of pEGFP plasmids into endothelial cells was carried out successfully via this SAW-induced cell perforation. The expression of GFP was observed after 24-hour incubation subsequent to the SAW treatment. In regard to the application of fs lasers in cellular and subcellular level studies, we applied the optical nanoscissoring technique based on fs lasers in biomechanical studies to study the mechanical properties of single SF in-situ. Integrated into a confocal microscope, the fs laser showed great power in manipulating targeted in-situ subcellular structures under real-time imaging without damaging nearby regions. Here, how oxidative challenges would alter the mechanical properties of SFs in myoblasts was firstly investigated using the optical nanoscissoring technique to comprehend the whole picture of muscle tissue injury and repair from the basics. The prestress of stress fibers after the oxidative challenges was found through our modified viscoelastic retraction model and experiment result.

The basics of intravascular optical coherence tomography

PubMed Central

Jąkała, Jacek; Kałuża, Grzegorz L.; Partyka, Łukasz; Proniewska, Klaudia; Pociask, Elżbieta; Zasada, Wojciech; Wojakowski, Wojciech; Gąsior, Zbigniew; Dudek, Dariusz

2015-01-01

Optical coherence tomography (OCT) has opened new horizons for intravascular coronary imaging. It utilizes near-infrared light to provide a microscopic insight into the pathology of coronary arteries in vivo. Optical coherence tomography is also capable of identifying the chemical composition of atherosclerotic plaques and detecting traits of their vulnerability. At present it is the only tool to measure the thickness of the fibrous cap covering the lipid core of the atheroma, and thus it is an exceptional modality to detect plaques that are prone to rupture (thin fibrous cap atheromas). Moreover, it facilitates distinguishing between plaque rupture and plaque erosion as a cause of acute intracoronary thrombosis. Optical coherence tomography is applied to guide angioplasties of coronary lesions and to assess outcomes of percutaneous coronary interventions broadly. It identifies stent malapposition, dissections, and thrombosis with unprecedented precision. Furthermore, OCT helps to monitor vessel healing after stenting. It evaluates the coverage of stent struts by the neointima and detects in-stent neoatherosclerosis. With so much potential, new studies are warranted to determine OCT's clinical impact. The following review presents the technical background, basics of OCT image interpretation, and practical tips for adequate OCT imaging, and outlines its established and potential clinical application. PMID:26161097

Development of a high brightness ultrafast Transmission Electron Microscope based on a laser-driven cold field emission source.

PubMed

Houdellier, F; Caruso, G M; Weber, S; Kociak, M; Arbouet, A

2018-03-01

We report on the development of an ultrafast Transmission Electron Microscope based on a cold field emission source which can operate in either DC or ultrafast mode. Electron emission from a tungsten nanotip is triggered by femtosecond laser pulses which are tightly focused by optical components integrated inside a cold field emission source close to the cathode. The properties of the electron probe (brightness, angular current density, stability) are quantitatively determined. The measured brightness is the largest reported so far for UTEMs. Examples of imaging, diffraction and spectroscopy using ultrashort electron pulses are given. Finally, the potential of this instrument is illustrated by performing electron holography in the off-axis configuration using ultrashort electron pulses. Copyright © 2017 Elsevier B.V. All rights reserved.

Reflectance confocal microscope for imaging oral tissues in vivo, potentially with line scanning as a low-cost approach for clinical use

NASA Astrophysics Data System (ADS)

Peterson, Gary; Abeytunge, Sanjeewa; Eastman, Zachary; Rajadhyaksha, Milind

2012-02-01

Reflectance confocal microscopy with a line scanning approach potentially offers a smaller, simpler and less expensive approach than traditional methods of point scanning for imaging in living tissues. With one moving mechanical element (galvanometric scanner), a linear array detector and off-the-shelf optics, we designed a compact (102x102x76mm) line scanning confocal reflectance microscope (LSCRM) for imaging human tissues in vivo in a clinical setting. Custom-designed electronics, based on field programmable gate array (FPGA) logic has been developed. With 405 nm illumination and a custom objective lens of numerical aperture 0.5, lateral resolution was measured to be 0.8 um (calculated 0.64 um). The calculated optical sectioning is 3.2 um. Preliminary imaging shows nuclear and cellular detail in human skin and oral epithelium in vivo. Blood flow is also visualized in the deeper connective tissue (lamina propria) in oral mucosa. Since a line is confocal only in one dimension (parallel) but not in the other, the detection is more sensitive to multiply scattered out of focus background noise than in the traditional point scanning configuration. Based on the results of our translational studies thus far, a simpler, smaller and lower-cost approach based on a LSCRM appears to be promising for clinical imaging.

Operating microscopes: past, present, and future.

PubMed

Uluç, Kutluay; Kujoth, Gregory C; Başkaya, Mustafa K

2009-09-01

The operating microscope is a fixture of modern surgical facilities, and it is a critically important factor in the success of many of the most complex and difficult surgical interventions used in medicine today. The rise of this key surgical tool reflects advances in understanding the principles of optics and vision that have occurred over centuries. The development of reading spectacles in the late 13th century led to the construction of early compound microscopes in the 16th and 17th centuries by Lippershey, Janssen, Galileo, Hooke, and others. Perhaps surprisingly, Leeuwenhoek's simple microscopes of this era offered improved performance over his contemporaries' designs. The intervening years saw improvements that reduced the spherical and chromatic aberrations present in compound microscopes. By the late 19th century, Carl Zeiss and Ernst Abbe ushered the compound microscope into the beginnings of the modern era of commercial design and production. The introduction of the microscope into the operating room by Nylén in 1921 initiated a revolution in surgical practice that gained momentum throughout the 1950s with multiple refinements, the introduction of the Zeiss OPMI series, and Kurze's application of the microscope to neurosurgery in 1957. Many of the refinements of the last 50 years have greatly improved the handling and practical operation of the surgical microscope, considerations which are equally important to its optical performance. Today's sophisticated operating microscopes allow for advanced real-time angiographic and tumor imaging. In this paper the authors discuss what might be found in the operating rooms of tomorrow.

A fiber-optic fluorescence microscope using a consumer-grade digital camera for in vivo cellular imaging.

PubMed

Shin, Dongsuk; Pierce, Mark C; Gillenwater, Ann M; Williams, Michelle D; Richards-Kortum, Rebecca R

2010-06-23

Early detection is an essential component of cancer management. Unfortunately, visual examination can often be unreliable, and many settings lack the financial capital and infrastructure to operate PET, CT, and MRI systems. Moreover, the infrastructure and expense associated with surgical biopsy and microscopy are a challenge to establishing cancer screening/early detection programs in low-resource settings. Improvements in performance and declining costs have led to the availability of optoelectronic components, which can be used to develop low-cost diagnostic imaging devices for use at the point-of-care. Here, we demonstrate a fiber-optic fluorescence microscope using a consumer-grade camera for in vivo cellular imaging. The fiber-optic fluorescence microscope includes an LED light, an objective lens, a fiber-optic bundle, and a consumer-grade digital camera. The system was used to image an oral cancer cell line labeled with 0.01% proflavine. A human tissue specimen was imaged following surgical resection, enabling dysplastic and cancerous regions to be evaluated. The oral mucosa of a healthy human subject was imaged in vivo, following topical application of 0.01% proflavine. The fiber-optic microscope resolved individual nuclei in all specimens and tissues imaged. This capability allowed qualitative and quantitative differences between normal and precancerous or cancerous tissues to be identified. The optical efficiency of the system permitted imaging of the human oral mucosa in real time. Our results indicate this device as a useful tool to assist in the identification of early neoplastic changes in epithelial tissues. This portable, inexpensive unit may be particularly appropriate for use at the point-of-care in low-resource settings.

Volumetric HiLo microscopy employing an electrically tunable lens.

PubMed

Philipp, Katrin; Smolarski, André; Koukourakis, Nektarios; Fischer, Andreas; Stürmer, Moritz; Wallrabe, Ulrike; Czarske, Jürgen W

2016-06-27

Electrically tunable lenses exhibit strong potential for fast motion-free axial scanning in a variety of microscopes. However, they also lead to a degradation of the achievable resolution because of aberrations and misalignment between illumination and detection optics that are induced by the scan itself. Additionally, the typically nonlinear relation between actuation voltage and axial displacement leads to over- or under-sampled frame acquisition in most microscopic techniques because of their static depth-of-field. To overcome these limitations, we present an Adaptive-Lens-High-and-Low-frequency (AL-HiLo) microscope that enables volumetric measurements employing an electrically tunable lens. By using speckle-patterned illumination, we ensure stability against aberrations of the electrically tunable lens. Its depth-of-field can be adjusted a-posteriori and hence enables to create flexible scans, which compensates for irregular axial measurement positions. The adaptive HiLo microscope provides an axial scanning range of 1 mm with an axial resolution of about 4 μm and sub-micron lateral resolution over the full scanning range. Proof of concept measurements at home-built specimens as well as zebrafish embryos with reporter gene-driven fluorescence in the thyroid gland are shown.

Quantitative Imaging with a Mobile Phone Microscope

PubMed Central

Skandarajah, Arunan; Reber, Clay D.; Switz, Neil A.; Fletcher, Daniel A.

2014-01-01

Use of optical imaging for medical and scientific applications requires accurate quantification of features such as object size, color, and brightness. High pixel density cameras available on modern mobile phones have made photography simple and convenient for consumer applications; however, the camera hardware and software that enables this simplicity can present a barrier to accurate quantification of image data. This issue is exacerbated by automated settings, proprietary image processing algorithms, rapid phone evolution, and the diversity of manufacturers. If mobile phone cameras are to live up to their potential to increase access to healthcare in low-resource settings, limitations of mobile phone–based imaging must be fully understood and addressed with procedures that minimize their effects on image quantification. Here we focus on microscopic optical imaging using a custom mobile phone microscope that is compatible with phones from multiple manufacturers. We demonstrate that quantitative microscopy with micron-scale spatial resolution can be carried out with multiple phones and that image linearity, distortion, and color can be corrected as needed. Using all versions of the iPhone and a selection of Android phones released between 2007 and 2012, we show that phones with greater than 5 MP are capable of nearly diffraction-limited resolution over a broad range of magnifications, including those relevant for single cell imaging. We find that automatic focus, exposure, and color gain standard on mobile phones can degrade image resolution and reduce accuracy of color capture if uncorrected, and we devise procedures to avoid these barriers to quantitative imaging. By accommodating the differences between mobile phone cameras and the scientific cameras, mobile phone microscopes can be reliably used to increase access to quantitative imaging for a variety of medical and scientific applications. PMID:24824072

Transmission electron microscope CCD camera

DOEpatents

Downing, Kenneth H.

1999-01-01

In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

Assessment of Petrological Microscopes.

ERIC Educational Resources Information Center

Mathison, Charter Innes

1990-01-01

Presented is a set of procedures designed to check the design, ergonomics, illumination, function, optics, accessory equipment, and image quality of a microscope being considered for purchase. Functions for use in a petrology or mineralogy laboratory are stressed. (CW)

Graphene surface plasmons mediated thermal radiation

NASA Astrophysics Data System (ADS)

Li, Jiayu; Liu, Baoan; Shen, Sheng

2018-02-01

A graphene nanostructure can simultaneously serve as a plasmonic optical resonator and a thermal emitter when thermally heated up. The unique electronic and optical properties of graphene have rendered tremendous potential in the active manipulation of light and the microscopic energy transport in nanostructures. Here we show that the thermally pumped surface plasmonic modes along graphene nanoribbons could dramatically modulate their thermal emission spectra in both near- and far-fields. Based on the fluctuating surface current method implemented by the resistive boundary method, we directly calculate the thermal emission spectrum from single graphene ribbons and vertically paired graphene ribbons. Furthermore, we demonstrate that both the near- and far-field thermal emission from graphene nanostructures can be optimized by tuning the chemical potential of doped graphene. The general guideline to maximize the thermal emission is illustrated by the our recently developed theory on resonant thermal emitters modulated by quasi-normal modes.

Transmissive Nanohole Arrays for Massively-Parallel Optical Biosensing

PubMed Central

2015-01-01

A high-throughput optical biosensing technique is proposed and demonstrated. This hybrid technique combines optical transmission of nanoholes with colorimetric silver staining. The size and spacing of the nanoholes are chosen so that individual nanoholes can be independently resolved in massive parallel using an ordinary transmission optical microscope, and, in place of determining a spectral shift, the brightness of each nanohole is recorded to greatly simplify the readout. Each nanohole then acts as an independent sensor, and the blocking of nanohole optical transmission by enzymatic silver staining defines the specific detection of a biological agent. Nearly 10000 nanoholes can be simultaneously monitored under the field of view of a typical microscope. As an initial proof of concept, biotinylated lysozyme (biotin-HEL) was used as a model analyte, giving a detection limit as low as 0.1 ng/mL. PMID:25530982

Micro axial tomography: A miniaturized, versatile stage device to overcome resolution anisotropy in fluorescence light microscopy

NASA Astrophysics Data System (ADS)

Staier, Florian; Eipel, Heinz; Matula, Petr; Evsikov, Alexei V.; Kozubek, Michal; Cremer, Christoph; Hausmann, Michael

2011-09-01

With the development of novel fluorescence techniques, high resolution light microscopy has become a challenging technique for investigations of the three-dimensional (3D) micro-cosmos in cells and sub-cellular components. So far, all fluorescence microscopes applied for 3D imaging in biosciences show a spatially anisotropic point spread function resulting in an anisotropic optical resolution or point localization precision. To overcome this shortcoming, micro axial tomography was suggested which allows object tilting on the microscopic stage and leads to an improvement in localization precision and spatial resolution. Here, we present a miniaturized device which can be implemented in a motor driven microscope stage. The footprint of this device corresponds to a standard microscope slide. A special glass fiber can manually be adjusted in the object space of the microscope lens. A stepwise fiber rotation can be controlled by a miniaturized stepping motor incorporated into the device. By means of a special mounting device, test particles were fixed onto glass fibers, optically localized with high precision, and automatically rotated to obtain views from different perspective angles under which distances of corresponding pairs of objects were determined. From these angle dependent distance values, the real 3D distance was calculated with a precision in the ten nanometer range (corresponding here to an optical resolution of 10-30 nm) using standard microscopic equipment. As a proof of concept, the spindle apparatus of a mature mouse oocyte was imaged during metaphase II meiotic arrest under different perspectives. Only very few images registered under different rotation angles are sufficient for full 3D reconstruction. The results indicate the principal advantage of the micro axial tomography approach for many microscopic setups therein and also those of improved resolutions as obtained by high precision localization determination.

Demonstration of a plenoptic microscope based on laser optical feedback imaging.

PubMed

Glastre, Wilfried; Hugon, Olivier; Jacquin, Olivier; Guillet de Chatellus, Hugues; Lacot, Eric

2013-03-25

A new kind of plenoptic imaging system based on Laser Optical Feedback Imaging (LOFI) is presented and is compared to another previously existing device based on microlens array. Improved photometric performances, resolution and depth of field are obtained at the price of a slow point by point scanning. Main properties of plenoptic microscopes such as numerical refocusing on any curved surface or aberrations compensation are both theoretically and experimentally demonstrated with a LOFI-based device.

Four-dimensional Microscope-Integrated Optical Coherence Tomography to Visualize Suture Depth in Strabismus Surgery.

PubMed

Pasricha, Neel D; Bhullar, Paramjit K; Shieh, Christine; Carrasco-Zevallos, Oscar M; Keller, Brenton; Izatt, Joseph A; Toth, Cynthia A; Freedman, Sharon F; Kuo, Anthony N

2017-02-14

The authors report the use of swept-source microscope-integrated optical coherence tomography (SS-MIOCT), capable of live four-dimensional (three-dimensional across time) intraoperative imaging, to directly visualize suture depth during lateral rectus resection. Key surgical steps visualized in this report included needle depth during partial and full-thickness muscle passes along with scleral passes. [J Pediatr Ophthalmol Strabismus. 2017;54:e1-e5.]. Copyright 2017, SLACK Incorporated.

Surface plasmon resonance microscopy: achieving a quantitative optical response

PubMed Central

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

2016-01-01

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 configuration. 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. PMID:27782542

Microscope Integrated Intraoperative Spectral Domain Optical Coherence Tomography for Cataract Surgery: Uses and Applications.

PubMed

Das, Sudeep; Kummelil, Mathew Kurian; Kharbanda, Varun; Arora, Vishal; Nagappa, Somshekar; Shetty, Rohit; Shetty, Bhujang K

2016-05-01

To demonstrate the uses and applications of a microscope integrated intraoperative Optical Coherence Tomography in Micro Incision Cataract Surgery (MICS) and Femtosecond Laser Assisted Cataract Surgery (FLACS). Intraoperative real time imaging using the RESCAN™ 700 (Carl Zeiss Meditec, Oberkochen, Germany) was done for patients undergoing MICS as well as FLACS. The OCT videos were reviewed at each step of the procedure and the findings were noted and analyzed. Microscope Integrated Intraoperative Optical Coherence Tomography was found to be beneficial during all the critical steps of cataract surgery. We were able to qualitatively assess wound morphology in clear corneal incisions, in terms of subclinical Descemet's detachments, tears in the inner or outer wound lips, wound gaping at the end of surgery and in identifying the adequacy of stromal hydration, for both FLACS as well as MICS. It also enabled us to segregate true posterior polar cataracts from suspected cases intraoperatively. Deciding the adequate depth of trenching was made simpler with direct visualization. The final position of the intraocular lens in the capsular bag and the lack of bioadhesivity of hydrophobic acrylic lenses were also observed. Even though Microscope Integrated Intraoperative Optical Coherence Tomography is in its early stages for its application in cataract surgery, this initial assessment does show a very promising role for this technology in the future for cataract surgery both in intraoperative decision making as well as for training purposes.

Lensless on-chip imaging of cells provides a new tool for high-throughput cell-biology and medical diagnostics.

PubMed

Mudanyali, Onur; Erlinger, Anthony; Seo, Sungkyu; Su, Ting-Wei; Tseng, Derek; Ozcan, Aydogan

2009-12-14

Conventional optical microscopes image cells by use of objective lenses that work together with other lenses and optical components. While quite effective, this classical approach has certain limitations for miniaturization of the imaging platform to make it compatible with the advanced state of the art in microfluidics. In this report, we introduce experimental details of a lensless on-chip imaging concept termed LUCAS (Lensless Ultra-wide field-of-view Cell monitoring Array platform based on Shadow imaging) that does not require any microscope objectives or other bulky optical components to image a heterogeneous cell solution over an ultra-wide field of view that can span as large as approximately 18 cm(2). Moreover, unlike conventional microscopes, LUCAS can image a heterogeneous cell solution of interest over a depth-of-field of approximately 5 mm without the need for refocusing which corresponds to up to approximately 9 mL sample volume. This imaging platform records the shadows (i.e., lensless digital holograms) of each cell of interest within its field of view, and automated digital processing of these cell shadows can determine the type, the count and the relative positions of cells within the solution. Because it does not require any bulky optical components or mechanical scanning stages it offers a significantly miniaturized platform that at the same time reduces the cost, which is quite important for especially point of care diagnostic tools. Furthermore, the imaging throughput of this platform is orders of magnitude better than conventional optical microscopes, which could be exceedingly valuable for high-throughput cell-biology experiments.

Lensless On-chip Imaging of Cells Provides a New Tool for High-throughput Cell-Biology and Medical Diagnostics

PubMed Central

Mudanyali, Onur; Erlinger, Anthony; Seo, Sungkyu; Su, Ting-Wei; Tseng, Derek; Ozcan, Aydogan

2009-01-01

Conventional optical microscopes image cells by use of objective lenses that work together with other lenses and optical components. While quite effective, this classical approach has certain limitations for miniaturization of the imaging platform to make it compatible with the advanced state of the art in microfluidics. In this report, we introduce experimental details of a lensless on-chip imaging concept termed LUCAS (Lensless Ultra-wide field-of-view Cell monitoring Array platform based on Shadow imaging) that does not require any microscope objectives or other bulky optical components to image a heterogeneous cell solution over an ultra-wide field of view that can span as large as ~18 cm2. Moreover, unlike conventional microscopes, LUCAS can image a heterogeneous cell solution of interest over a depth-of-field of ~5 mm without the need for refocusing which corresponds to up to ~9 mL sample volume. This imaging platform records the shadows (i.e., lensless digital holograms) of each cell of interest within its field of view, and automated digital processing of these cell shadows can determine the type, the count and the relative positions of cells within the solution. Because it does not require any bulky optical components or mechanical scanning stages it offers a significantly miniaturized platform that at the same time reduces the cost, which is quite important for especially point of care diagnostic tools. Furthermore, the imaging throughput of this platform is orders of magnitude better than conventional optical microscopes, which could be exceedingly valuable for high-throughput cell-biology experiments. PMID:20010542

Study of a quasi-microscope design for planetary landers

NASA Technical Reports Server (NTRS)

Giat, O.; Brown, E. B.

1973-01-01

The Viking Lander fascimile camera, in its present form, provides for a minimum object distance of 1.9 meters, at which distance its resolution of 0.0007 radian provides an object resolution of 1.33 millimeters. It was deemed desirable, especially for follow-on Viking missions, to provide means for examing Martian terrain at resolutions considerably higher than that now provided. This led to the concept of quasi-microscope, an attachment to be used in conjunction with the fascimile camera to convert it to a low power microscope. The results are reported of an investigation to consider alternate optical configurations for the quasi-microscope and to develop optical designs for the selected system or systems. Initial requirements included consideration of object resolutions in the range of 2 to 50 micrometers, an available field of view of the order of 500 pixels, and no significant modifications to the fascimile camera.

Mosaic of Commemorative Microscope Substrate

NASA Technical Reports Server (NTRS)

2008-01-01

Written by electron beam lithography in the Microdevices Laboratory of NASA's Jet Propulsion Laboratory, this Optical Microscope substrate helps the Phoenix Mars Mission science team learn how to assemble individual microscope images into a mosaic by aligning rows of text.

Each line is about 0.1 millimeter tall, the average thickness of a human hair. Except for the Mogensen twins, the names are of babies born and team members lost during the original development of MECA (the Microscopy, Electrochemistry and Conductivity Analyzer) for the canceled 2001 Mars lander mission. The plaque also acknowledges the MECA 2001 principal investigator, now retired.

This image was taken by the MECA Optical Microscope on Sol 111, or the 111th day of the Phoenix mission (Sept. 16, 2008).

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by JPL, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

4D microscope-integrated OCT improves accuracy of ophthalmic surgical maneuvers

NASA Astrophysics Data System (ADS)

Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Shen, Liangbo; Todorich, Bozho; Shieh, Christine; Kuo, Anthony; Toth, Cynthia; Izatt, Joseph A.

2016-03-01

Ophthalmic surgeons manipulate micron-scale tissues using stereopsis through an operating microscope and instrument shadowing for depth perception. While ophthalmic microsurgery has benefitted from rapid advances in instrumentation and techniques, the basic principles of the stereo operating microscope have not changed since the 1930's. Optical Coherence Tomography (OCT) has revolutionized ophthalmic imaging and is now the gold standard for preoperative and postoperative evaluation of most retinal and many corneal procedures. We and others have developed initial microscope-integrated OCT (MIOCT) systems for concurrent OCT and operating microscope imaging, but these are limited to 2D real-time imaging and require offline post-processing for 3D rendering and visualization. Our previously presented 4D MIOCT system can record and display the 3D surgical field stereoscopically through the microscope oculars using a dual-channel heads-up display (HUD) at up to 10 micron-scale volumes per second. In this work, we show that 4D MIOCT guidance improves the accuracy of depth-based microsurgical maneuvers (with statistical significance) in mock surgery trials in a wet lab environment. Additionally, 4D MIOCT was successfully performed in 38/45 (84%) posterior and 14/14 (100%) anterior eye human surgeries, and revealed previously unrecognized lesions that were invisible through the operating microscope. These lesions, such as residual and potentially damaging retinal deformation during pathologic membrane peeling, were visualized in real-time by the surgeon. Our integrated system provides an enhanced 4D surgical visualization platform that can improve current ophthalmic surgical practice and may help develop and refine future microsurgical techniques.

A wide field-of-view microscope based on holographic focus grid

NASA Astrophysics Data System (ADS)

Wu, Jigang; Cui, Xiquan; Zheng, Guoan; Lee, Lap Man; Yang, Changhuei

2010-02-01

We have developed a novel microscope technique that can achieve wide field-of-view (FOV) imaging and yet possess resolution that is comparable to conventional microscope. The principle of wide FOV microscope system breaks the link between resolution and FOV magnitude of traditional microscopes. Furthermore, by eliminating bulky optical elements from its design and utilizing holographic optical elements, the wide FOV microscope system is more cost-effective. In our system, a hologram was made to focus incoming collimated beam into a focus grid. The sample is put in the focal plane and the transmissions of the focuses are detected by an imaging sensor. By scanning the incident angle of the incoming beam, the focus grid will scan across the sample and the time-varying transmission can be detected. We can then reconstruct the transmission image of the sample. The resolution of microscopic image is limited by the size of the focus formed by the hologram. The scanning area of each focus spot is determined by the separation of the focus spots and can be made small for fast imaging speed. We have fabricated a prototype system with a 2.4-mm FOV and 1-μm resolution. The prototype system was used to image onion skin cells for a demonstration. The preliminary experiments prove the feasibility of the wide FOV microscope technique, and the possibility of a wider FOV system with better resolution.

Microscope-on-Chip Using Micro-Channel and Solid State Image Sensors

NASA Technical Reports Server (NTRS)

Wang, Yu

2000-01-01

Recently, Jet Propulsion Laboratory has invented and developed a miniature optical microscope, microscope-on-chip using micro-channel and solid state image sensors. It is lightweight, low-power, fast speed instrument, it has no image lens, does not need focus adjustment, and the total mass is less than 100g. A prototype has been built and demonstrated at JPL.

The PC9A Filter Screening Tool

DTIC Science & Technology

2016-02-01

conjunction with an optical microscope for identification of other important debris such as glass beads. The FST has now been installed at RAAF East...conservative screening limits need to be sent for detailed laboratory analysis. Laboratory analysis has traditionally involved a manual microscopic ...Electron Microscope with Energy Dispersive Spectroscopy (SEM EDS) to determine the composition and likely source. The Engine Maintenance Manual

A high-resolution multimode digital microscope system.

PubMed

Salmon, Edward D; Shaw, Sidney L; Waters, Jennifer C; Waterman-Storer, Clare M; Maddox, Paul S; Yeh, Elaine; Bloom, Kerry

2013-01-01

This chapter describes the development of a high-resolution, multimode digital imaging system based on a wide-field epifluorescent and transmitted light microscope, and a cooled charge-coupled device (CCD) camera. The three main parts of this imaging system are Nikon FXA microscope, Hamamatsu C4880 cooled CCD camera, and MetaMorph digital imaging system. This chapter presents various design criteria for the instrument and describes the major features of the microscope components-the cooled CCD camera and the MetaMorph digital imaging system. The Nikon FXA upright microscope can produce high resolution images for both epifluorescent and transmitted light illumination without switching the objective or moving the specimen. The functional aspects of the microscope set-up can be considered in terms of the imaging optics, the epi-illumination optics, the transillumination optics, the focus control, and the vibration isolation table. This instrument is somewhat specialized for microtubule and mitosis studies, and it is also applicable to a variety of problems in cellular imaging, including tracking proteins fused to the green fluorescent protein in live cells. The instrument is also valuable for correlating the assembly dynamics of individual cytoplasmic microtubules (labeled by conjugating X-rhodamine to tubulin) with the dynamics of membranes of the endoplasmic reticulum (labeled with DiOC6) and the dynamics of the cell cortex (by differential interference contrast) in migrating vertebrate epithelial cells. This imaging system also plays an important role in the analysis of mitotic mutants in the powerful yeast genetic system Saccharomyces cerevisiae. Copyright © 1998 Elsevier Inc. All rights reserved.

A high-resolution combined scanning laser and widefield polarizing microscope for imaging at temperatures from 4 K to 300 K.

PubMed

Lange, M; Guénon, S; Lever, F; Kleiner, R; Koelle, D

2017-12-01

Polarized light microscopy, as a contrast-enhancing technique for optically anisotropic materials, is a method well suited for the investigation of a wide variety of effects in solid-state physics, as, for example, birefringence in crystals or the magneto-optical Kerr effect (MOKE). We present a microscopy setup that combines a widefield microscope and a confocal scanning laser microscope with polarization-sensitive detectors. By using a high numerical aperture objective, a spatial resolution of about 240 nm at a wavelength of 405 nm is achieved. The sample is mounted on a 4 He continuous flow cryostat providing a temperature range between 4 K and 300 K, and electromagnets are used to apply magnetic fields of up to 800 mT with variable in-plane orientation and 20 mT with out-of-plane orientation. Typical applications of the polarizing microscope are the imaging of the in-plane and out-of-plane magnetization via the longitudinal and polar MOKE, imaging of magnetic flux structures in superconductors covered with a magneto-optical indicator film via the Faraday effect, or imaging of structural features, such as twin-walls in tetragonal SrTiO 3 . The scanning laser microscope furthermore offers the possibility to gain local information on electric transport properties of a sample by detecting the beam-induced voltage change across a current-biased sample. This combination of magnetic, structural, and electric imaging capabilities makes the microscope a viable tool for research in the fields of oxide electronics, spintronics, magnetism, and superconductivity.

A high-resolution combined scanning laser and widefield polarizing microscope for imaging at temperatures from 4 K to 300 K

NASA Astrophysics Data System (ADS)

Lange, M.; Guénon, S.; Lever, F.; Kleiner, R.; Koelle, D.

2017-12-01

Polarized light microscopy, as a contrast-enhancing technique for optically anisotropic materials, is a method well suited for the investigation of a wide variety of effects in solid-state physics, as, for example, birefringence in crystals or the magneto-optical Kerr effect (MOKE). We present a microscopy setup that combines a widefield microscope and a confocal scanning laser microscope with polarization-sensitive detectors. By using a high numerical aperture objective, a spatial resolution of about 240 nm at a wavelength of 405 nm is achieved. The sample is mounted on a 4He continuous flow cryostat providing a temperature range between 4 K and 300 K, and electromagnets are used to apply magnetic fields of up to 800 mT with variable in-plane orientation and 20 mT with out-of-plane orientation. Typical applications of the polarizing microscope are the imaging of the in-plane and out-of-plane magnetization via the longitudinal and polar MOKE, imaging of magnetic flux structures in superconductors covered with a magneto-optical indicator film via the Faraday effect, or imaging of structural features, such as twin-walls in tetragonal SrTiO3. The scanning laser microscope furthermore offers the possibility to gain local information on electric transport properties of a sample by detecting the beam-induced voltage change across a current-biased sample. This combination of magnetic, structural, and electric imaging capabilities makes the microscope a viable tool for research in the fields of oxide electronics, spintronics, magnetism, and superconductivity.

Laser tweezer actuated microphotonic array devices for high resolution imaging and analysis in chip-based biosystems

NASA Astrophysics Data System (ADS)

Birkbeck, Aaron L.

A new technology is developed that functionally integrates arrays of lasers and micro-optics into microfluidic systems for the purpose of imaging, analyzing, and manipulating objects and biological cells. In general, the devices and technologies emerging from this area either lack functionality through the reliance on mechanical systems or provide a serial-based, time consuming approach. As compared to the current state of art, our all-optical design methodology has several distinguishing features, such as parallelism, high efficiency, low power, auto-alignment, and high yield fabrication methods, which all contribute to minimizing the cost of the integration process. The potential use of vertical cavity surface emitting lasers (VCSELs) for the creation of two-dimensional arrays of laser optical tweezers that perform independently controlled, parallel capture, and transport of large numbers of individual objects and biological cells is investigated. One of the primary biological applications for which VCSEL array sourced laser optical tweezers are considered is the formation of engineered tissues through the manipulation and spatial arrangement of different types of cells in a co-culture. Creating devices that combine laser optical tweezers with select micro-optical components permits optical imaging and analysis functions to take place inside the microfluidic channel. One such device is a micro-optical spatial filter whose motion and alignment is controlled using a laser optical tweezer. Unlike conventional spatial filter systems, our device utilizes a refractive optical element that is directly incorporated onto the lithographically patterned spatial filter. This allows the micro-optical spatial filter to automatically align itself in three-dimensions to the focal point of the microscope objective, where it then filters out the higher frequency additive noise components present in the laser beam. As a means of performing high resolution imaging in the microfluidic channel, we developed a novel technique that integrates the capacity of a laser tweezer to optically trap and manipulate objects in three-dimensions with the resolution-enhanced imaging capabilities of a solid immersion lens (SIL). In our design, the SIL is a free-floating device whose imaging beam, motion control and alignment is provided by a laser optical tweezer, which allows the microfluidic SIL to image in areas that are inaccessible to traditional solid immersion microscopes.

Distortion Correction for a Brewster Angle Microscope Using an Optical Grating.

PubMed

Sun, Zhe; Zheng, Desheng; Baldelli, Steven

2017-02-21

A distortion-corrected Brewster angle microscope (DC-BAM) is designed, constructed, and tested based on the combination of an optical grating and a relay lens. Avoiding the drawbacks of most conventional BAM instruments, this configuration corrects the image propagation direction and consequently provides an image in focus over the entire field of view without any beam scanning or imaging reconstruction. This new BAM can be applied to both liquid and solid subphases with good spatial resolution in static and dynamic studies.

Modeling off-resonant nonlinear-optical cascading in mesoscopic thin films and guest-host molecular systems

NASA Astrophysics Data System (ADS)

Dawson, Nathan J.; Andrews, James H.; Crescimanno, Michael

2013-12-01

A model for off-resonant microscopic cascading of (hyper)polarizabilities is developed using a self-consistent field approach to study mesoscopic systems of nonlinear polarizable atoms and molecules. We find enhancements in the higher-order susceptibilities resulting from geometrical and boundary orientation effects. We include an example of the dependence on excitation beam cross sectional structure and a simplified derivation of the microscopic cascading of the nonlinear-optical response in guest-host systems.

Linear and nonlinear optical characteristics of Te nanoparticles-doped germanate glasses

NASA Astrophysics Data System (ADS)

Xu, Zhousu; Guo, Qiangbing; Liu, Chang; Ma, Zhijun; Liu, Xiaofeng; Qiu, Jianrong

2016-10-01

Te nanoparticles (NPs)-doped GeO2-MgO-B2O3-Al2O3-TeO2 glasses were prepared by the conventional melt-quenching method. Based on X-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscope observation, the coloration of the glass at high TeO2 concentration is ascribed to the precipitation of elemental Te NPs with a size of 5-10 nm in the germanate glass. Optical absorption spectra and nonlinear optical (NLO) properties of the glass samples were analyzed by UV-3600 spectrophotometry and Z-scan technique, respectively. The nonlinear absorption coefficient ( β) and the imaginary part of the third-order NLO susceptibility (Im χ (3)) were estimated to be 1.74 cm/GW and 1.142 × 10-12 esu for laser power of 95 μW, respectively. Due to the excellent NLO properties, the Te NPs-doped germanate glasses may have potential applications for ultrafast optical switch and photonics.

Feedback effects in optical communication systems: characteristic curve for single-mode InGaAsP lasers.

PubMed

Brivio, F; Reverdito, C; Sacchi, G; Chiaretti, G; Milani, M

1992-08-20

An experimental analysis of InGaAsP injection lasers shows an unexpected decrease of the differential quantum efficiency as a function of injected current when optical power is fed back into the active cavity of a diode inserted into a long transmission line. To investigate the response of laser diodes to optical feedback, we base our analysis on a microscopic model, resulting in a set of coupled equations that include the microscopic parameters that characterize the material and the device. This description takes into account the nonlinear dependence of the interband carrier lifetime on the level of optical feedback. Good agreement between the analytical description and experimental data is obtained for threshold current and differential quantum efficiency as functions of the feedback ratio.

Microsphere-aided optical microscopy and its applications for super-resolution imaging

NASA Astrophysics Data System (ADS)

Upputuri, Paul Kumar; Pramanik, Manojit

2017-12-01

The spatial resolution of a standard optical microscope (SOM) is limited by diffraction. In visible spectrum, SOM can provide ∼ 200 nm resolution. To break the diffraction limit several approaches were developed including scanning near field microscopy, metamaterial super-lenses, nanoscale solid immersion lenses, super-oscillatory lenses, confocal fluorescence microscopy, techniques that exploit non-linear response of fluorophores like stimulated emission depletion microscopy, stochastic optical reconstruction microscopy, etc. Recently, photonic nanojet generated by a dielectric microsphere was used to break the diffraction limit. The microsphere-approach is simple, cost-effective and can be implemented under a standard microscope, hence it has gained enormous attention for super-resolution imaging. In this article, we briefly review the microsphere approach and its applications for super-resolution imaging in various optical imaging modalities.

The temperature-dependency of the optical band gap of ZnO measured by electron energy-loss spectroscopy in a scanning transmission electron microscope

NASA Astrophysics Data System (ADS)

Granerød, Cecilie S.; Galeckas, Augustinas; Johansen, Klaus Magnus; Vines, Lasse; Prytz, Øystein

2018-04-01

The optical band gap of ZnO has been measured as a function of temperature using Electron Energy-Loss Spectroscopy (EELS) in a (Scanning) Transmission Electron Microscope ((S)TEM) from approximately 100 K up towards 1000 K. The band gap narrowing shows a close to linear dependency for temperatures above 250 K and is accurately described by Varshni, Bose-Einstein, Pässler and Manoogian-Woolley models. Additionally, the measured band gap is compared with both optical absorption measurements and photoluminescence data. STEM-EELS is here shown to be a viable technique to measure optical band gaps at elevated temperatures, with an available temperature range up to 1500 K and the benefit of superior spatial resolution.

Photonic-crystal membranes for optical detection of single nano-particles, designed for biosensor application.

PubMed

Grepstad, Jon Olav; Kaspar, Peter; Solgaard, Olav; Johansen, Ib-Rune; Sudbø, Aasmund S

2012-03-26

A sensor designed to detect bio-molecules is presented. The sensor exploits a planar 2D photonic crystal (PC) membrane with sub-micron thickness and through holes, to induce high optical fields that allow detection of nano-particles smaller than the diffraction limit of an optical microscope. We report on our design and fabrication of a PC membrane with a nano-particle trapped inside. We have also designed and built an imaging system where an optical microscope and a CCD camera are used to take images of the PC membrane. Results show how the trapped nano-particle appears as a bright spot in the image. In a first experimental realization of the imaging system, single particles with a radius of 75 nm can be detected.

High-speed atomic force microscopy combined with inverted optical microscopy for studying cellular events

PubMed Central

Suzuki, Yuki; Sakai, Nobuaki; Yoshida, Aiko; Uekusa, Yoshitsugu; Yagi, Akira; Imaoka, Yuka; Ito, Shuichi; Karaki, Koichi; Takeyasu, Kunio

2013-01-01

A hybrid atomic force microscopy (AFM)-optical fluorescence microscopy is a powerful tool for investigating cellular morphologies and events. However, the slow data acquisition rates of the conventional AFM unit of the hybrid system limit the visualization of structural changes during cellular events. Therefore, high-speed AFM units equipped with an optical/fluorescence detection device have been a long-standing wish. Here we describe the implementation of high-speed AFM coupled with an optical fluorescence microscope. This was accomplished by developing a tip-scanning system, instead of a sample-scanning system, which operates on an inverted optical microscope. This novel device enabled the acquisition of high-speed AFM images of morphological changes in individual cells. Using this instrument, we conducted structural studies of living HeLa and 3T3 fibroblast cell surfaces. The improved time resolution allowed us to image dynamic cellular events. PMID:23823461

High-speed atomic force microscopy combined with inverted optical microscopy for studying cellular events.

PubMed

Suzuki, Yuki; Sakai, Nobuaki; Yoshida, Aiko; Uekusa, Yoshitsugu; Yagi, Akira; Imaoka, Yuka; Ito, Shuichi; Karaki, Koichi; Takeyasu, Kunio

2013-01-01

A hybrid atomic force microscopy (AFM)-optical fluorescence microscopy is a powerful tool for investigating cellular morphologies and events. However, the slow data acquisition rates of the conventional AFM unit of the hybrid system limit the visualization of structural changes during cellular events. Therefore, high-speed AFM units equipped with an optical/fluorescence detection device have been a long-standing wish. Here we describe the implementation of high-speed AFM coupled with an optical fluorescence microscope. This was accomplished by developing a tip-scanning system, instead of a sample-scanning system, which operates on an inverted optical microscope. This novel device enabled the acquisition of high-speed AFM images of morphological changes in individual cells. Using this instrument, we conducted structural studies of living HeLa and 3T3 fibroblast cell surfaces. The improved time resolution allowed us to image dynamic cellular events.

Development and demonstration of a water-window soft x-ray microscope using a Z-pinching capillary discharge source

NASA Astrophysics Data System (ADS)

Nawaz, M. F.; Jancarek, Alexandr; Nevrkla, Michal; Duda, Martin Jakub; Pina, Ladislav

2017-05-01

The development and demonstration of a soft X-ray (SXR) microscope, based on a Z-pinching capillary discharge source has been realized. The Z-pinching plasma acts as a source of SXR radiation. A ceramic capacitor bank is pulsed charged up to 80 kV, and discharged through a pre- ionized nitrogen filled ceramic capillary. The discharge current has an amplitude of 25 kA. Working within the water-window spectral region (λ = 2.88 nm), corresponding to the 1s2-1s2p quantum transition of helium-like nitrogen (N5+), the microscope has a potential in exploiting the natural contrast existing between the K-absorption edges of carbon and oxygen as the main constituents of biological materials, and hence imaging them with high spatial resolution. The SXR microscope uses the grazing incidence ellipsoidal condenser mirror for the illumination, and the Fresnel zone plate optics for the imaging of samples onto a BI-CCD camera. The half- pitch spatial resolution of 100 nm [1] was achieved, as demonstrated by the knife-edge test. In order to enhance the photon-flux at the sample plane, a new scheme for focusing the radiation, from multiple capillary sources has been investigated. Details about the source, and the construction of the microscope are presented and discussed.

Noninvasive identification of bladder cancer with subsurface backscattered light

NASA Astrophysics Data System (ADS)

Bigio, Irving J.; Mourant, Judith R.; Boyer, James D.; Johnson, Tamara M.; Shimada, Tsutomu; Conn, Richard L.

1994-05-01

We have developed and are testing early prototypes of an optical biopsy system (OBS) for detection of cancer and other tissue pathologies. The OBS invokes a unique approach to optical diagnosis of tissue pathologies based on the elastic scattering properties, over a wide range of wavelengths, of the microscopic structure of the tissue. Absorption bands in the tissue also add useful complexity to the spectral data collected. The data acquisition and storage/display time with the OBS instrument is approximately 1 second. Thus, in addition to the reduced invasiveness of this technique compared with current state-of- the-art methods, the OBS offers the possibility of impressively faster diagnostic assessment. The OBS employs a small fiber-optic probe that is amendable to use with any endoscope, catheter or hypodermic, or to direct surface examination (e.g., as in skin cancer or cervical cancer). We report here specifically on its potential application in the detection of bladder cancer.

Modern technologies for retinal scanning and imaging: an introduction for the biomedical engineer

PubMed Central

2014-01-01

This review article is meant to help biomedical engineers and nonphysical scientists better understand the principles of, and the main trends in modern scanning and imaging modalities used in ophthalmology. It is intended to ease the communication between physicists, medical doctors and engineers, and hopefully encourage “classical” biomedical engineers to generate new ideas and to initiate projects in an area which has traditionally been dominated by optical physics. Most of the methods involved are applicable to other areas of biomedical optics and optoelectronics, such as microscopic imaging, spectroscopy, spectral imaging, opto-acoustic tomography, fluorescence imaging etc., all of which are with potential biomedical application. Although all described methods are novel and important, the emphasis of this review has been placed on three technologies introduced in the 1990’s and still undergoing vigorous development: Confocal Scanning Laser Ophthalmoscopy, Optical Coherence Tomography, and polarization-sensitive retinal scanning. PMID:24779618

Towards a Quantum Interface between Diamond Spin Qubits and Phonons in an Optical Trap

NASA Astrophysics Data System (ADS)

Ji, Peng; Momeen, M. Ummal; Hsu, Jen-Feng; D'Urso, Brian; Dutt, Gurudev

2014-05-01

We introduce a method to optically levitate a pre-selected nanodiamond crystal in air or vacuum. The nanodiamond containing nitrogen-vacancy (NV) centers is suspended on a monolayer of graphene transferred onto a patterned substrate. Laser light is focused onto the sample, using a home-built confocal microscope with a high numerical aperture (NA = 0.9) objective, simultaneously burning the graphene and creating a 3D optical trap that captures the falling nano-diamond at the beam waist. The trapped diamond is an ultra-high-Q mechanical oscillator, allowing us to engineer strong linear and quadratic coupling between the spin of the NV center and the phonon mode. The system could result in an ideal quantum interface between a spin qubit and vibrational phonon mode, potentially enabling applications in quantum information processing and sensing the development of quantum information storage and processing.

CRISTAPRESS: an optical cell for structure development in high-pressure crystallization.

PubMed

Boyer, S A E; Fournier, F E J; Gandin, Ch-A; Haudin, J-M

2014-01-01

An original optical high-pressure cell, named CRISTAPRESS, has been especially designed to investigate phase transitions of complex liquids, i.e., polymers, polymer blends, nano-composites, etc. The design of the cell is based on the optical properties of morphological entities through in situ light depolarizing microscopic observations. Pressure up to 200 MPa with a fine temperature control up to 300 °C can be applied. A striking advantage of this cell is the possibility to select the pressure transmitting medium that can be water, silicone oil, a fluid in the supercritical state, etc. The potential of the novel technique was demonstrated by carrying out time-resolved measurements during polymer crystallization induced by water pressure. These preliminary experimental investigations permit to discriminate the role of the barometric and thermal histories on the kinetics of polymer growth, as well as on the subsequent morphologies. It should lead to new reliable crystallization kinetics models.

A portable liquid crystal-based polarized light system for the detection of organophosphorus nerve gas.

PubMed

He, Feng Jie; Liu, Hui Long; Chen, Long Cong; Xiong, Xing Liang

2018-03-01

Liquid crystal (LC)-based sensors have the advantageous properties of being fast, sensitive, and label-free, the results of which can be accessed directly only through the naked eye. However, the inherent disadvantages possessed by LC sensors, such as relying heavily on polarizing microscopes and the difficulty to quantify, have limited the possibility of field applications. Herein, we have addressed these issues by constructing a portable polarized detection system with constant temperature control. This system is mainly composed of four parts: the LC cell, the optics unit, the automatic temperature control unit, and the image processing unit. The LC cell was based on the ordering transitions of LCs in the presence of analytes. The optics unit based on the imaging principle of LCs was designed to substitute the polarizing microscope for the real-time observation. The image processing unit is expected to quantify the concentration of analytes. The results have shown that the presented system can detect dimethyl methyl phosphonate (a stimulant for organophosphorus nerve gas) within 25 s, and the limit of detection is about 10 ppb. In all, our portable system has potential in field applications.

A portable liquid crystal-based polarized light system for the detection of organophosphorus nerve gas

NASA Astrophysics Data System (ADS)

He, Feng Jie; Liu, Hui Long; Chen, Long Cong; Xiong, Xing Liang

2018-03-01

Liquid crystal (LC)-based sensors have the advantageous properties of being fast, sensitive, and label-free, the results of which can be accessed directly only through the naked eye. However, the inherent disadvantages possessed by LC sensors, such as relying heavily on polarizing microscopes and the difficulty to quantify, have limited the possibility of field applications. Herein, we have addressed these issues by constructing a portable polarized detection system with constant temperature control. This system is mainly composed of four parts: the LC cell, the optics unit, the automatic temperature control unit, and the image processing unit. The LC cell was based on the ordering transitions of LCs in the presence of analytes. The optics unit based on the imaging principle of LCs was designed to substitute the polarizing microscope for the real-time observation. The image processing unit is expected to quantify the concentration of analytes. The results have shown that the presented system can detect dimethyl methyl phosphonate (a stimulant for organophosphorus nerve gas) within 25 s, and the limit of detection is about 10 ppb. In all, our portable system has potential in field applications.

Water without windows: Evaluating the performance of open cell transmission electron microscopy under saturated water vapor conditions, and assessing its potential for microscopy of hydrated biological specimens.

PubMed

Cassidy, Cathal; Yamashita, Masao; Cheung, Martin; Kalale, Chola; Adaniya, Hidehito; Kuwahara, Ryusuke; Shintake, Tsumoru

2017-01-01

We have performed open cell transmission electron microscopy experiments through pure water vapor in the saturation pressure regime (>0.6 kPa), in a modern microscope capable of sub-Å resolution. We have systematically studied achievable pressure levels, stability and gas purity, effective thickness of the water vapor column and associated electron scattering processes, and the effect of gas pressure on electron optical resolution and image contrast. For example, for 1.3 kPa pure water vapor and 300kV electrons, we report pressure stability of ± 20 Pa over tens of minutes, effective thickness of 0.57 inelastic mean free paths, lattice resolution of 0.14 nm on a reference Au specimen, and no significant degradation in contrast or stability of a biological specimen (M13 virus, with 6 nm body diameter). We have also done some brief experiments to confirm feasibility of loading specimens into an in situ water vapor ambient without exposure to intermediate desiccating conditions. Finally, we have also checked if water experiments had any discernible impact on the microscope performance, and report pertinent vacuum and electron optical data, for reference purposes.

Structural and optical studies on spin coated ZnO-graphene conjugated thin films

NASA Astrophysics Data System (ADS)

Srinatha, N.; Angadi, Basavaraj; Son, D. I.; Choi, W. K.

2018-05-01

ZnO-Graphene conjugated thin films were prepared using spin coating technique for different spin rates. Prior to the deposition, ZnO-Graphene nanoparticles were synthesized and their particle size and conjugation was studied through Transmission electron microscope (TEM). The deposited films were characterized using grazing incidence x-ray diffractometer (GIXRD), atomic force microscope (AFM) and UV-Visible spectrometer for their crystallinity, surface topographic features and optical properties. GIXRD patterns confirms the presence of both ZnO and Graphene related crystalline peaks supports the TEM results, which shows the quasi core-shell type conjugation of ZnO-Graphene particles. The crystallinity as well as thickness of the films found to decrease with increase of spin rate. AFM results reveal the uniform, smooth and homogeneity of films and also good adhesivity of ZnO-Graphene with glass substrates. No significant change in the transmittance and absorption with spin rate is observed, while the band gap energy found to decrease due to the reduction in the thickness of the films and conjugation of ZnO-Graphene. All films exhibit˜90 % transmittance in the visible wavelength region, could be potential candidates for optoelectronics and transparent conducting oxide (TCO) applications.

Optical scanning tests of complex CMOS microcircuits

NASA Technical Reports Server (NTRS)

Levy, M. E.; Erickson, J. J.

1977-01-01

The new test method was based on the use of a raster-scanned optical stimulus in combination with special electrical test procedures. The raster-scanned optical stimulus was provided by an optical spot scanner, an instrument that combines a scanning optical microscope with electronic instrumentation to process and display the electric photoresponse signal induced in a device that is being tested.

Two-photon microscope for multisite microphotolysis of caged neurotransmitters in acute brain slices

PubMed Central

Losavio, Bradley E.; Iyer, Vijay; Saggau, Peter

2009-01-01

We developed a two-photon microscope optimized for physiologically manipulating single neurons through their postsynaptic receptors. The optical layout fulfills the stringent design criteria required for high-speed, high-resolution imaging in scattering brain tissue with minimal photodamage. We detail the practical compensation of spectral and temporal dispersion inherent in fast laser beam scanning with acousto-optic deflectors, as well as a set of biological protocols for visualizing nearly diffraction-limited structures and delivering physiological synaptic stimuli. The microscope clearly resolves dendritic spines and evokes electrophysiological transients in single neurons that are similar to endogenous responses. This system enables the study of multisynaptic integration and will assist our understanding of single neuron function and dendritic computation. PMID:20059271

Multimodal nonlinear microscope based on a compact fiber-format laser source

NASA Astrophysics Data System (ADS)

Crisafi, Francesco; Kumar, Vikas; Perri, Antonio; Marangoni, Marco; Cerullo, Giulio; Polli, Dario

2018-01-01

We present a multimodal non-linear optical (NLO) laser-scanning microscope, based on a compact fiber-format excitation laser and integrating coherent anti-Stokes Raman scattering (CARS), stimulated Raman scattering (SRS) and two-photon-excitation fluorescence (TPEF) on a single platform. We demonstrate its capabilities in simultaneously acquiring CARS and SRS images of a blend of 6-μm poly(methyl methacrylate) beads and 3-μm polystyrene beads. We then apply it to visualize cell walls and chloroplast of an unprocessed fresh leaf of Elodea aquatic plant via SRS and TPEF modalities, respectively. The presented NLO microscope, developed in house using off-the-shelf components, offers full accessibility to the optical path and ensures its easy re-configurability and flexibility.

Microscope-integrated optical coherence tomography: A new surgical tool in vitreoretinal surgery.

PubMed

Jayadev, Chaitra; Dabir, Supriya; Vinekar, Anand; Shah, Urmil; Vaid, Tania; Yadav, Naresh Kumar

2015-05-01

Optical coherence tomography (OCT) has revolutionized imaging of ocular structures and various disease conditions. Though it has been used in the clinic for some decades, the OCT has only recently found its way into the operating theater. Early attempts at intraoperative OCT, hand-held and microscope mounted, have already improved our understanding of the surgical pathology and the role it might play in surgical decision-making. The microscope-integrated OCT now allows seamless, high-resolution, real-time imaging of surgical maneuvers from the incision to wound closure. Visualization of instruments and intraoperative tissue manipulation are possible with this in vivo modality and, therefore, help improve the outcome of surgery. In this article, we describe the advantages it offers during various vitreoretinal procedures.

Deep two-photon microscopic imaging through brain tissue using the second singlet state from fluorescent agent chlorophyll α in spinach leaf

NASA Astrophysics Data System (ADS)

Shi, Lingyan; Rodríguez-Contreras, Adrián; Budansky, Yury; Pu, Yang; An Nguyen, Thien; Alfano, Robert R.

2014-06-01

Two-photon (2P) excitation of the second singlet (S) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S2 state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat brain tissue in combination with 2P microscopic imaging. Strong emission at the peak wavelength of 685 nm under the 2P S state of Chl α enabled the imaging depth up to 450 μm through rat brain tissue.

Deep two-photon microscopic imaging through brain tissue using the second singlet state from fluorescent agent chlorophyll α in spinach leaf.

PubMed

Shi, Lingyan; Rodríguez-Contreras, Adrián; Budansky, Yury; Pu, Yang; Nguyen, Thien An; Alfano, Robert R

2014-06-01

Two-photon (2P) excitation of the second singlet (S₂) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S₂ state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat brain tissue in combination with 2P microscopic imaging. Strong emission at the peak wavelength of 685 nm under the 2P S₂ state of Chl α enabled the imaging depth up to 450 μm through rat brain tissue.

Measurement of the microscopic viscosities of microfluids with a dynamic optical tweezers system

NASA Astrophysics Data System (ADS)

Zhang, Yuquan; Wu, Xiaojing; Wang, Yijia; Zhu, Siwei; Gao, Bruce Z.; Yuan, X.-C.

2014-06-01

Viscosity coefficients of microfluids—Newtonian and non-Newtonian—were explored through the rotational motion of a particle trapped by optical tweezers in a microflute. Unlike conventional methods based on viscometers, our microfluidic system employs samples of less than 30 μl to complete a measurement. Viscosity coefficients of ethanol and fetal bovine serum, as typical examples of Newtonian and non-Newtonian fluids, were obtained experimentally, and found to be in excellent agreement with theoretical predictions. Additionally, a practical application to a DNA solution with incremental ethidium bromide content was employed and the results are consistent with clinical data, indicating that our system provides a potentially important complementary tool for use in such biological and medical applications.

Photoluminescence study of carbon dots from ginger and galangal herbs using microwave technique

NASA Astrophysics Data System (ADS)

Isnaeni; Rahmawati, I.; Intan, R.; Zakaria, M.

2018-03-01

Carbon dots are new type of fluorescent nanoparticle that can be synthesis easily from natural sources. We have synthesized carbon dots from ginger and galangal herbs using microwave technique and studied their optical properties. We synthesized colloidal carbon dots in water solvent by varying microwave processing time. UV-Vis absorbance, photoluminescence, time-resolved photoluminescence, and transmission electron microscope were utilized to study properties of carbon dots. We found that microwave processing time significantly affect optical properties of synthesized carbon dots. UV-Vis absorbance spectra and time-resolved photoluminescence results show that luminescent of carbon dots is dominated by recombination process from n-π* surface energy level. With further development, these carbon dots are potential for several applications.

Coherent anti-Stokes Raman scattering spectroscope/microscope based on a widely tunable laser source

NASA Astrophysics Data System (ADS)

Dementjev, A.; Gulbinas, V.; Serbenta, A.; Kaucikas, M.; Niaura, G.

2010-03-01

We present a coherent anti-Stokes Raman scattering (CARS) microscope based on a robust and simple laser source. A picosecond laser operating in a cavity dumping regime at the 1 MHz repetition rate was used to pump a traveling wave optical parametric generator, which serves as a two-color excitation light source for the CARS microscope. We demonstrate the ability of the presented CARS microscope to measure CARS spectra and images by using several detection schemes.

Dual-mode optical microscope based on single-pixel imaging

NASA Astrophysics Data System (ADS)

Rodríguez, A. D.; Clemente, P.; Tajahuerce, E.; Lancis, J.

2016-07-01

We demonstrate an inverted microscope that can image specimens in both reflection and transmission modes simultaneously with a single light source. The microscope utilizes a digital micromirror device (DMD) for patterned illumination altogether with two single-pixel photosensors for efficient light detection. The system, a scan-less device with no moving parts, works by sequential projection of a set of binary intensity patterns onto the sample that are codified onto a modified commercial DMD. Data to be displayed are geometrically transformed before written into a memory cell to cancel optical artifacts coming from the diamond-like shaped structure of the micromirror array. The 24-bit color depth of the display is fully exploited to increase the frame rate by a factor of 24, which makes the technique practicable for real samples. Our commercial DMD-based LED-illumination is cost effective and can be easily coupled as an add-on module for already existing inverted microscopes. The reflection and transmission information provided by our dual microscope complement each other and can be useful for imaging non-uniform samples and to prevent self-shadowing effects.

Stimulated penetrating keratoplasty using real-time virtual intraoperative surgical optical coherence tomography

PubMed Central

Lee, Changho; Kim, Kyungun; Han, Seunghoon; Kim, Sehui; Lee, Jun Hoon; Kim, Hong kyun; Kim, Chulhong; Jung, Woonggyu; Kim, Jeehyun

2014-01-01

Abstract. An intraoperative surgical microscope is an essential tool in a neuro- or ophthalmological surgical environment. Yet, it has an inherent limitation to classify subsurface information because it only provides the surface images. To compensate for and assist in this problem, combining the surgical microscope with optical coherence tomography (OCT) has been adapted. We developed a real-time virtual intraoperative surgical OCT (VISOCT) system by adapting a spectral-domain OCT scanner with a commercial surgical microscope. Thanks to our custom-made beam splitting and image display subsystems, the OCT images and microscopic images are simultaneously visualized through an ocular lens or the eyepiece of the microscope. This improvement helps surgeons to focus on the operation without distraction to view OCT images on another separate display. Moreover, displaying the OCT live images on the eyepiece helps surgeon’s depth perception during the surgeries. Finally, we successfully processed stimulated penetrating keratoplasty in live rabbits. We believe that these technical achievements are crucial to enhance the usability of the VISOCT system in a real surgical operating condition. PMID:24604471

Holographic pixel super-resolution in portable lensless on-chip microscopy using a fiber-optic array.

PubMed

Bishara, Waheb; Sikora, Uzair; Mudanyali, Onur; Su, Ting-Wei; Yaglidere, Oguzhan; Luckhart, Shirley; Ozcan, Aydogan

2011-04-07

We report a portable lensless on-chip microscope that can achieve <1 µm resolution over a wide field-of-view of ∼ 24 mm(2) without the use of any mechanical scanning. This compact on-chip microscope weighs ∼ 95 g and is based on partially coherent digital in-line holography. Multiple fiber-optic waveguides are butt-coupled to light emitting diodes, which are controlled by a low-cost micro-controller to sequentially illuminate the sample. The resulting lensfree holograms are then captured by a digital sensor-array and are rapidly processed using a pixel super-resolution algorithm to generate much higher resolution holographic images (both phase and amplitude) of the objects. This wide-field and high-resolution on-chip microscope, being compact and light-weight, would be important for global health problems such as diagnosis of infectious diseases in remote locations. Toward this end, we validate the performance of this field-portable microscope by imaging human malaria parasites (Plasmodium falciparum) in thin blood smears. Our results constitute the first-time that a lensfree on-chip microscope has successfully imaged malaria parasites.

Three-dimensional reconstruction of highly complex microscopic samples using scanning electron microscopy and optical flow estimation.

PubMed

Baghaie, Ahmadreza; Pahlavan Tafti, Ahmad; Owen, Heather A; D'Souza, Roshan M; Yu, Zeyun

2017-01-01

Scanning Electron Microscope (SEM) as one of the major research and industrial equipment for imaging of micro-scale samples and surfaces has gained extensive attention from its emerge. However, the acquired micrographs still remain two-dimensional (2D). In the current work a novel and highly accurate approach is proposed to recover the hidden third-dimension by use of multi-view image acquisition of the microscopic samples combined with pre/post-processing steps including sparse feature-based stereo rectification, nonlocal-based optical flow estimation for dense matching and finally depth estimation. Employing the proposed approach, three-dimensional (3D) reconstructions of highly complex microscopic samples were achieved to facilitate the interpretation of topology and geometry of surface/shape attributes of the samples. As a byproduct of the proposed approach, high-definition 3D printed models of the samples can be generated as a tangible means of physical understanding. Extensive comparisons with the state-of-the-art reveal the strength and superiority of the proposed method in uncovering the details of the highly complex microscopic samples.

Chrysophyte cysts as potential environmental indicators.

USGS Publications Warehouse

Adam, D.P.; Mahood, A.D.

1981-01-01

Many chrysophyte algae produce morphologically distinctive, siliceous, microscopic cysts during a resting stage of their life cycles; these cysts are often preserved in sediments. Scanning electron microscopy and Nomarski optics permit much more detailed observation of these cysts than was heretofore possible. Many cyst types are found only in specific habitats, such as montane lakes, wet meadows, ephemeral ponds, and Sphagnum bogs. In the samples studied, cysts seem to be most common in fluctuating fresh-water habitats of low to moderate pH and some winter freezing. Chrysophyte cysts have the potential to be a useful tool for modern environmental assessments and paleoecological studies of Cenozoic fresh-water lacustrine deposits. -from Authors

Volumetric Light-field Encryption at the Microscopic Scale

PubMed Central

Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu

2017-01-01

We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale. PMID:28059149

Simple and cost-effective hardware and software for functional brain mapping using intrinsic optical signal imaging.

PubMed

Harrison, Thomas C; Sigler, Albrecht; Murphy, Timothy H

2009-09-15

We describe a simple and low-cost system for intrinsic optical signal (IOS) imaging using stable LED light sources, basic microscopes, and commonly available CCD cameras. IOS imaging measures activity-dependent changes in the light reflectance of brain tissue, and can be performed with a minimum of specialized equipment. Our system uses LED ring lights that can be mounted on standard microscope objectives or video lenses to provide a homogeneous and stable light source, with less than 0.003% fluctuation across images averaged from 40 trials. We describe the equipment and surgical techniques necessary for both acute and chronic mouse preparations, and provide software that can create maps of sensory representations from images captured by inexpensive 8-bit cameras or by 12-bit cameras. The IOS imaging system can be adapted to commercial upright microscopes or custom macroscopes, eliminating the need for dedicated equipment or complex optical paths. This method can be combined with parallel high resolution imaging techniques such as two-photon microscopy.

Combined use of optical and electron microscopic techniques for the measurement of hygroscopic property, chemical composition, and morphology of individual aerosol particles.

PubMed

Ahn, Kang-Ho; Kim, Sun-Man; Jung, Hae-Jin; Lee, Mi-Jung; Eom, Hyo-Jin; Maskey, Shila; Ro, Chul-Un

2010-10-01

In this work, an analytical method for the characterization of the hygroscopic property, chemical composition, and morphology of individual aerosol particles is introduced. The method, which is based on the combined use of optical and electron microscopic techniques, is simple and easy to apply. An optical microscopic technique was used to perform the visual observation of the phase transformation and hygroscopic growth of aerosol particles on a single particle level. A quantitative energy-dispersive electron probe X-ray microanalysis, named low-Z particle EPMA, was used to perform a quantitative chemical speciation of the same individual particles after the measurement of the hygroscopic property. To validate the analytical methodology, the hygroscopic properties of artificially generated NaCl, KCl, (NH(4))(2)SO(4), and Na(2)SO(4) aerosol particles of micrometer size were investigated. The practical applicability of the analytical method for studying the hygroscopic property, chemical composition, and morphology of ambient aerosol particles is demonstrated.

Eyecup scope—optical recordings of light stimulus-evoked fluorescence signals in the retina

PubMed Central

Hausselt, Susanne E.; Breuninger, Tobias; Castell, Xavier; Denk, Winfried; Margolis, David J.; Detwiler, Peter B.

2009-01-01

Dendritic signals play an essential role in processing visual information in the retina. To study them in neurites too small for electrical recording, we developed an instrument that combines a multi-photon (MP) microscope with a through-the-objective high-resolution visual stimulator. An upright microscope was designed that uses the objective lens for both MP imaging and delivery of visual stimuli to functionally intact retinal explants or eyecup preparations. The stimulator consists of a miniature liquid-crystal-on-silicon display coupled into the optical path of an infrared-excitation laser-scanning microscope. A pair of custom-made dichroic filters allows light from the excitation laser and three spectral bands (‘colors’) from the stimulator to reach the retina, leaving two intermediate bands for fluorescence imaging. Special optics allow displacement of the stimulator focus relative to the imaging focus. Spatially resolved changes in calcium-indicator fluorescence in response to visual stimuli were recorded in dendrites of different types of mammalian retinal neurons. PMID:19023590

Enhanced optical coupling and Raman scattering via microscopic interface engineering

NASA Astrophysics Data System (ADS)

Thompson, Jonathan V.; Hokr, Brett H.; Kim, Wihan; Ballmann, Charles W.; Applegate, Brian E.; Jo, Javier A.; Yamilov, Alexey; Cao, Hui; Scully, Marlan O.; Yakovlev, Vladislav V.

2017-11-01

Spontaneous Raman scattering is an extremely powerful tool for the remote detection and identification of various chemical materials. However, when those materials are contained within strongly scattering or turbid media, as is the case in many biological and security related systems, the sensitivity and range of Raman signal generation and detection is severely limited. Here, we demonstrate that through microscopic engineering of the optical interface, the optical coupling of light into a turbid material can be substantially enhanced. This improved coupling facilitates the enhancement of the Raman scattering signal generated by molecules within the medium. In particular, we detect at least two-orders of magnitude more spontaneous Raman scattering from a sample when the pump laser light is focused into a microscopic hole in the surface of the sample. Because this approach enhances both the interaction time and interaction region of the laser light within the material, its use will greatly improve the range and sensitivity of many spectroscopic techniques, including Raman scattering and fluorescence emission detection, inside highly scattering environments.

Volumetric Light-field Encryption at the Microscopic Scale

NASA Astrophysics Data System (ADS)

Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu

2017-01-01

We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale.

Free-standing GaN grating couplers and rib waveguide for planar photonics at telecommunication wavelength

NASA Astrophysics Data System (ADS)

Liu, Qifa; Wang, Wei

2018-01-01

Gallium Nitride (GaN) free-standing planar photonic device at telecommunication wavelength based on GaN-on-silicon platform was presented. The free-standing structure was realized by particular double-side fabrication process, which combining GaN front patterning, Si substrate back releasing and GaN slab etching. The actual device parameters were identified via the physical characterizations employing scanning electron microscope (SEM), atomic force microscope (AFM) and reflectance spectra testing. High coupling efficiency and good light confinement properties of the gratings and rib waveguide at telecommunication wavelength range were verified by finite element method (FEM) simulation. This work illustrates the potential of new GaN photonic structure which will enable new functions for planar photonics in communication and sensing applications, and is favorable for the realization of integrated optical circuit.

Suspension and simple optical characterization of two-dimensional membranes

NASA Astrophysics Data System (ADS)

Northeast, David B.; Knobel, Robert G.

2018-03-01

We report on a method for suspending two-dimensional crystal materials in an electronic circuit using an only photoresists and solvents. Graphene and NbSe2 are suspended tens of nanometers above metal electrodes with clamping diameters of several microns. The optical cavity formed from the membrane/air/metal structures enables a quick method to measure the number of layers and the gap separation using comparisons between the expected colour and optical microscope images. This characterization technique can be used with just an illuminated microscope with a digital camera which makes it adaptable to environments where other means of characterization are not possible, such as inside nitrogen glove boxes used in handling oxygen-sensitive materials.

Microscopic Optical Projection Tomography In Vivo

PubMed Central

Meyer, Heiko; Ripoll, Jorge; Tavernarakis, Nektarios

2011-01-01

We describe a versatile optical projection tomography system for rapid three-dimensional imaging of microscopic specimens in vivo. Our tomographic setup eliminates the in xy and z strongly asymmetric resolution, resulting from optical sectioning in conventional confocal microscopy. It allows for robust, high resolution fluorescence as well as absorption imaging of live transparent invertebrate animals such as C. elegans. This system offers considerable advantages over currently available methods when imaging dynamic developmental processes and animal ageing; it permits monitoring of spatio-temporal gene expression and anatomical alterations with single-cell resolution, it utilizes both fluorescence and absorption as a source of contrast, and is easily adaptable for a range of small model organisms. PMID:21559481

Enhancement of graphene visibility on transparent substrates by refractive index optimization.

PubMed

Gonçalves, Hugo; Alves, Luís; Moura, Cacilda; Belsley, Michael; Stauber, Tobias; Schellenberg, Peter

2013-05-20

Optical reflection microscopy is one of the main imaging tools to visualize graphene microstructures. Here is reported a novel method that employs refractive index optimization in an optical reflection microscope, which greatly improves the visibility of graphene flakes. To this end, an immersion liquid with a refractive index that is close to that of the glass support is used in-between the microscope lens and the support improving the contrast and resolution of the sample image. Results show that the contrast of single and few layer graphene crystals and structures can be enhanced by a factor of 4 compared to values commonly achieved with transparent substrates using optical reflection microscopy lacking refractive index optimization.

Dynamic-focusing microscope objective for optical coherence tomography

NASA Astrophysics Data System (ADS)

Murali, Supraja; Rolland, Jannick

2007-01-01

Optical Coherence Tomography (OCT) is a novel optical imaging technique that has assumed significant importance in bio-medical imaging in the last two decades because it is non-invasive and provides accurate, high resolution images of three dimensional cross-sections of body tissue, exceeding the capabilities of the current predominant imaging technique - ultrasound. In this paper, the application of high resolution OCT, known as optical coherence microscopy (OCM) is investigated for in vivo detection of abnormal skin pathology for the early diagnosis of cancer. A main challenge in OCM is maintaining invariant resolution throughout the sample. The technology presented is based on a dynamic focusing microscope imaging probe conceived for skin imaging and the detection of abnormalities in the epithelium. A novel method for dynamic focusing in the biological sample is presented using variable-focus lens technology to obtain three dimensional images with invariant resolution throughout the cross-section and depth of the sample is presented and discussed. A low coherence broadband source centered at near IR wavelengths is used to illuminate the sample. The design, analysis and predicted performance of the dynamic focusing microscope objective designed for dynamic three dimensional imaging at 5μm resolution for the chosen broadband spectrum is presented.

Atomic force-multi-optical imaging integrated microscope for monitoring molecular dynamics in live cells.

PubMed

Trache, Andreea; Meininger, Gerald A

2005-01-01

A novel hybrid imaging system is constructed integrating atomic force microscopy (AFM) with a combination of optical imaging techniques that offer high spatial resolution. The main application of this instrument (the NanoFluor microscope) is the study of mechanotransduction with an emphasis on extracellular matrix-integrin-cytoskeletal interactions and their role in the cellular responses to changes in external chemical and mechanical factors. The AFM allows the quantitative assessment of cytoskeletal changes, binding probability, adhesion forces, and micromechanical properties of the cells, while the optical imaging applications allow thin sectioning of the cell body at the coverslip-cell interface, permitting the study of focal adhesions using total internal reflection fluorescence (TIRF) and internal reflection microscopy (IRM). Combined AFM-optical imaging experiments show that mechanical stimulation at the apical surface of cells induces a force-generating cytoskeletal response, resulting in focal contact reorganization on the basal surface that can be monitored in real time. The NanoFluor system is also equipped with a novel mechanically aligned dual camera acquisition system for synthesized Forster resonance energy transfer (FRET). The integrated NanoFluor microscope system is described, including its characteristics, applications, and limitations.

Assessing the Penetrating Abilities of Experimental Preparation with Dental Infiltrant Features Using Optical Microscope: Preliminary Study.

PubMed

Skucha-Nowak, Małgorzata; Machorowska-Pieniążek, Agnieszka; Tanasiewicz, Marta

2016-01-01

The aim of the infiltration technique is to penetrate demineralized enamel with a low viscosity resin. Icon® (DMG) is the first ever and so far the only dental infiltrant. Bacteriostaticity is one of the properties that should be inherent in dental infiltrants, but Icon lacks this feature. The aim of the preliminary study was to properly choose a dye which would allow us to assess the penetrating abilities of our own, experimental preparation with features of a dental infiltrant with bacteriostatic properties and to compare using an optical microscope the depth of infiltration of the designed experimental preparation with the infiltrant available on the market. The preparation is supposed to infiltrate decalcified human enamel and be assessed with an optical microscope. Eosin, neutral fuchsine and methylene blue were added to experimental preparation with dental infiltrant features and to Icon® (DMG) in order to assess the depth of penetration of the experimental solution into the decalcified layers of enamel. The experimental solution mixes well with eosin, neutral fuchsine, and methylene blue. During the preliminary study, the authors concluded that the experimental solution mixes well with methylene blue, neutral fuchsine, and eosin. An addition of eosin to a preparation which infiltrates inner, demineralized enamel layers, facilitates the assessment of such a preparation with an optical microscope. A designed experimental solution with the main ingredients, i.e., 2-hydroxyethyl methacrylate (HEMA) and tetraethylene glycol dimethacrylate (TEGDMA) with a ratio of 75% to 25% penetrates the demineralized (decalcified) inner parts of the enamel and polymerizes when exposed to light. In order to assess the infiltration of the experimental solution into the demineralized enamel layers, it is required to improve the measurement techniques that utilize optical microscopy.

Fabrication of core-shell micro/nanoparticles for programmable dual drug release by emulsion electrospraying

NASA Astrophysics Data System (ADS)

Wang, Yazhou; Zhang, Yiqiong; Wang, Bochu; Cao, Yang; Yu, Qingsong; Yin, Tieying

2013-06-01

The study aimed at constructing a novel drug delivery system for programmable multiple drug release controlled with core-shell structure. The core-shell structure consisted of chitosan nanoparticles as core and polyvinylpyrrolidone micro/nanocoating as shell to form core-shell micro/nanoparticles, which was fabricated by ionic gelation and emulsion electrospray methods. As model drug agents, Naproxen and rhodamine B were encapsulated in the core and shell regions, respectively. The core-shell micro/nanoparticles thus fabricated were characterized and confirmed by scanning electron microscope, transmission electron microscope, and fluorescence optical microscope. The core-shell micro/nanoparticles showed good release controllability through drug release experiment in vitro. It was noted that a programmable release pattern for dual drug agents was also achieved by adjusting their loading regions in the core-shell structures. The results indicate that emulsion electrospraying technology is a promising approach in fabrication of core-shell micro/nanoparticles for programmable dual drug release. Such a novel multi-drug delivery system has a potential application for the clinical treatment of cancer, tuberculosis, and tissue engineering.

Biocompatible near-infrared fluorescent nanoparticles for macro and microscopic in vivo functional bioimaging

PubMed Central

Chu, Liliang; Wang, Shaowei; Li, Kanghui; Xi, Wang; Zhao, Xinyuan; Qian, Jun

2014-01-01

Near-infrared (NIR) imaging technology has been widely used for biomedical research and applications, since it can achieve deep penetration in biological tissues due to less absorption and scattering of NIR light. In our research, polymer nanoparticles with NIR fluorophores doped were synthesized. The morphology, absorption/emission features and chemical stability of the fluorescent nanoparticles were characterized, separately. NIR fluorescent nanoparticles were then utilized as bright optical probes for macro in vivo imaging of mice, including sentinel lymph node (SLN) mapping, as well as distribution and excretion monitoring of nanoparticles in animal body. Furthermore, we applied the NIR fluorescent nanoparticles in in vivo microscopic bioimaging via a confocal microscope. Under the 635 nm-CW excitation, the blood vessel architecture in the ear and the brain of mice, which were administered with nanoparticles, was visualized very clearly. The imaging depth of our one-photon microscopy, which was assisted with NIR fluorescent nanoprobes, can reach as deep as 500 μm. Our experiments show that NIR fluorescent nanoparticles have great potentials in various deep-tissue imaging applications. PMID:25426331

Microscopic modeling of nitride intersubband absorbance

NASA Astrophysics Data System (ADS)

Montano, Ines; Allerman, A. A.; Wierer, J. J.; Moseley, M.; Skogen, E. J.; Tauke-Pedretti, A.; Vawter, G. A.

III-nitride intersubband structures have recently attracted much interest because of their potential for a wide variety of applications ranging from electro-optical modulators to terahertz quantum cascade lasers. To overcome present simulation limitations we have developed a microscopic absorbance simulator for nitride intersubband devices. Our simulator calculates the band structure of nitride intersubband systems using a fully coupled 8x8 k.p Hamiltonian and determines the material response of a single period in a density-matrix-formalism by solving the Heisenberg equation including many-body and dephasing contributions. After calculating the polarization due to intersubband transitions in a single period, the resulting absorbance of a superlattice structure including radiative coupling between the different periods is determined using a non-local Green's-function formalism. As a result our simulator allows us to predict intersubband absorbance of superlattice structures with microscopically determined lineshapes and linewidths accounting for both many-body and correlation contributions. This work is funded by Sandia National Laboratories Laboratory Directed Research and Development program. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin.

Multiplane optical microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Tongcang; Ota, Sadao; Kim, Jeongmin

This disclosure provides systems, methods, and apparatus related to optical microscopy. In one aspect, an apparatus includes a sample holder, a first objective lens, a plurality of optical components, a second objective lens, and a mirror. The apparatus may directly image a cross-section of a sample oblique to or parallel to the optical axis of the first objective lens, without scanning.

Environmental Integrity of Coating/Metal Interface

DTIC Science & Technology

1989-03-01

occurred. For this explanation to be correct, microblisters would be optically detectable using a microscope with Nomarsky contrast or by examining the...polymer surface with an interferometric microscope. Both of these techniques have been tried, but neither of them was able to detect any surface

A simple optical tweezers for trapping polystyrene particles

NASA Astrophysics Data System (ADS)

Shiddiq, Minarni; Nasir, Zulfa; Yogasari, Dwiyana

2013-09-01

Optical tweezers is an optical trap. For decades, it has become an optical tool that can trap and manipulate any particle from the very small size like DNA to the big one like bacteria. The trapping force comes from the radiation pressure of laser light which is focused to a group of particles. Optical tweezers has been used in many research areas such as atomic physics, medical physics, biophysics, and chemistry. Here, a simple optical tweezers has been constructed using a modified Leybold laboratory optical microscope. The ocular lens of the microscope has been removed for laser light and digital camera accesses. A laser light from a Coherent diode laser with wavelength λ = 830 nm and power 50 mW is sent through an immersion oil objective lens with magnification 100 × and NA 1.25 to a cell made from microscope slides containing polystyrene particles. Polystyrene particles with size 3 μm and 10 μm are used. A CMOS Thorlabs camera type DCC1545M with USB Interface and Thorlabs camera lens 35 mm are connected to a desktop and used to monitor the trapping and measure the stiffness of the trap. The camera is accompanied by camera software which makes able for the user to capture and save images. The images are analyzed using ImageJ and Scion macro. The polystyrene particles have been trapped successfully. The stiffness of the trap depends on the size of the particles and the power of the laser. The stiffness increases linearly with power and decreases as the particle size larger.

An Improved Optical Tweezers Assay for Measuring the Force Generation of Single Kinesin Molecules

PubMed Central

Nicholas, Matthew P.; Rao, Lu; Gennerich, Arne

2014-01-01

Numerous microtubule-associated molecular motors, including several kinesins and cytoplasmic dynein, produce opposing forces that regulate spindle and chromosome positioning during mitosis. The motility and force generation of these motors are therefore critical to normal cell division, and dysfunction of these processes may contribute to human disease. Optical tweezers provide a powerful method for studying the nanometer motility and piconewton force generation of single motor proteins in vitro. Using kinesin-1 as a prototype, we present a set of step-by-step, optimized protocols for expressing a kinesin construct (K560-GFP) in Escherichia coli, purifying it, and studying its force generation in an optical tweezers microscope. We also provide detailed instructions on proper alignment and calibration of an optical trapping microscope. These methods provide a foundation for a variety of similar experiments. PMID:24633799

Imaging arrangement and microscope

DOEpatents

Pertsinidis, Alexandros; Chu, Steven

2015-12-15

An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.

Optically Sectioned Imaging of Microvasculature of In-Vivo and Ex-Vivo Thick Tissue Models with Speckle-illumination HiLo Microscopy and HiLo Image Processing Implementation in MATLAB Architecture

NASA Astrophysics Data System (ADS)

Suen, Ricky Wai

The work described in this thesis covers the conversion of HiLo image processing into MATLAB architecture and the use of speckle-illumination HiLo microscopy for use of ex-vivo and in-vivo imaging of thick tissue models. HiLo microscopy is a wide-field fluorescence imaging technique and has been demonstrated to produce optically sectioned images comparable to confocal in thin samples. The imaging technique was developed by Jerome Mertz and the Boston University Biomicroscopy Lab and has been implemented in our lab as a stand-alone optical setup and a modification to a conventional fluorescence microscope. Speckle-illumination HiLo microscopy combines two images taken under speckle-illumination and standard uniform-illumination to generate an optically sectioned image that reject out-of-focus fluorescence. The evaluated speckle contrast in the images is used as a weighting function where elements that move out-of-focus have a speckle contrast that decays to zero. The experiments shown here demonstrate the capability of our HiLo microscopes to produce optically-sectioned images of the microvasculature of ex-vivo and in-vivo thick tissue models. The HiLo microscope were used to image the microvasculature of ex-vivo mouse heart sections prepared for optical histology and the microvasculature of in-vivo rodent dorsal window chamber models. Studies in label-free surface profiling with HiLo microscopy is also presented.

Continuum generation in optical fibers for high-resolution holographic coherence domain imaging application

NASA Astrophysics Data System (ADS)

Li, Linghui; Gruzdev, Vitaly; Yu, Ping; Chen, J. K.

2009-02-01

High pulse energy continuum generation in conventional multimode optical fibers has been studied for potential applications to a holographic optical coherence imaging system. As a new imaging modality for the biological tissue imaging, high-resolution holographic optical coherence imaging requires a broadband light source with a high brightness, a relatively low spatial coherence and a high stability. A broadband femtosecond laser can not be used as the light source of holographic imaging system since the laser creates a lot of speckle patterns. By coupling high peak power femtosecond laser pulses into a multimode optical fiber, nonlinear optical effects cause a continuum generation that can be served as a super-bright and broadband light source. In our experiment, an amplified femtosecond laser was coupled into the fiber through a microscopic objective. We measured the FWHM of the continuum generation as a function of incident pulse energy from 80 nJ to 800 μJ. The maximum FWHM is about 8 times higher than that of the input pulses. The stability was analyzed at different pump energies, integration times and fiber lengths. The spectral broadening and peak position show that more than two processes compete in the fiber.

Optical-sectioning microscopy of protoporphyrin IX fluorescence in human gliomas: standardization and quantitative comparison with histology

NASA Astrophysics Data System (ADS)

Wei, Linpeng; Chen, Ye; Yin, Chengbo; Borwege, Sabine; Sanai, Nader; Liu, Jonathan T. C.

2017-04-01

Systemic delivery of 5-aminolevulinic acid leads to enhanced fluorescence image contrast in many tumors due to the increased accumulation of protoporphyrin IX (PpIX), a fluorescent porphyrin that is associated with tumor burden and proliferation. The value of PpIX-guided resection of malignant gliomas has been demonstrated in prospective randomized clinical studies in which a twofold greater extent of resection and improved progression-free survival have been observed. In low-grade gliomas and at the diffuse infiltrative margins of all gliomas, PpIX fluorescence is often too weak to be detected with current low-resolution surgical microscopes that are used in operating rooms. However, it has been demonstrated that high-resolution optical-sectioning microscopes are capable of detecting the sparse and punctate accumulations of PpIX that are undetectable via conventional low-power surgical fluorescence microscopes. To standardize the performance of high-resolution optical-sectioning devices for future clinical use, we have developed an imaging phantom and methods to ensure that the imaging of PpIX-expressing brain tissues can be performed reproducibly. Ex vivo imaging studies with a dual-axis confocal microscope demonstrate that these methods enable the acquisition of images from unsectioned human brain tissues that quantitatively and consistently correlate with images of histologically processed tissue sections.

Method to deterministically study photonic nanostructures in different experimental instruments.

PubMed

Husken, B H; Woldering, L A; Blum, C; Vos, W L

2009-01-01

We describe an experimental method to recover a single, deterministically fabricated nanostructure in various experimental instruments without the use of artificially fabricated markers, with the aim to study photonic structures. Therefore, a detailed map of the spatial surroundings of the nanostructure is made during the fabrication of the structure. These maps are made using a series of micrographs with successively decreasing magnifications. The graphs reveal intrinsic and characteristic geometric features that can subsequently be used in different setups to act as markers. As an illustration, we probe surface cavities with radii of 65 nm on a silica opal photonic crystal with various setups: a focused ion beam workstation; a scanning electron microscope (SEM); a wide field optical microscope and a confocal microscope. We use cross-correlation techniques to recover a small area imaged with the SEM in a large area photographed with the optical microscope, which provides a possible avenue to automatic searching. We show how both structural and optical reflectivity data can be obtained from one and the same nanostructure. Since our approach does not use artificial grids or markers, it is of particular interest for samples whose structure is not known a priori, like samples created solely by self-assembly. In addition, our method is not restricted to conducting samples.

[Intraoperative Optical Coherence Tomography (MI-OCT) for the Treatment of Corneal Dystrophies].

PubMed

Siebelmann, Sebastian; Matthaei, Mario; Heindl, Ludwig M; Bachmann, Björn O; Cursiefen, Claus

2018-06-01

The surgical treatment of corneal dystrophies develops rapidly as the use of lamellar corneal grafting techniques continue. While penetrating keratoplasty was the gold standard for treating a variety of dystrophies a few years ago, the affected layers of the cornea can, nowadays, be selectively replaced or ablated using laser technology. Of particular importance for these methods is optical coherence tomography, which has recently been integrated into surgical microscopes (MI-OCT). Literature overview from PubMed and Google.scholar.de supplemented with own imaging data. The MI-OCT enables the intraoperative real-time monitoring of different ophthalmic surgical procedures, such as deep anterior lamellar keratoplasty, Descemet's membrane endothelial keratoplasty, as well as minimally-invasive procedures, such as phototherapeutic keratectomy. In addition, it enables an evaluation of the cornea, but also of structures of the anterior chamber, in situations in which the cornea, for example, is clouded by an edema. Microscope-integrated, intraoperative optical coherence tomography (MI-OCT) represents a useful supplement to the normal surgical microscope. It is superior to the sole surgical microscope, especially in already severely clouded corneas, and represents a sensible supplement, especially for novel lamellar transplantation procedures. Prospective randomized trials are necessary to increase safety and efficacy when using MI-OCT for different indications. Georg Thieme Verlag KG Stuttgart · New York.

Light field creating and imaging with different order intensity derivatives

NASA Astrophysics Data System (ADS)

Wang, Yu; Jiang, Huan

2014-10-01

Microscopic image restoration and reconstruction is a challenging topic in the image processing and computer vision, which can be widely applied to life science, biology and medicine etc. A microscopic light field creating and three dimensional (3D) reconstruction method is proposed for transparent or partially transparent microscopic samples, which is based on the Taylor expansion theorem and polynomial fitting. Firstly the image stack of the specimen is divided into several groups in an overlapping or non-overlapping way along the optical axis, and the first image of every group is regarded as reference image. Then different order intensity derivatives are calculated using all the images of every group and polynomial fitting method based on the assumption that the structure of the specimen contained by the image stack in a small range along the optical axis are possessed of smooth and linear property. Subsequently, new images located any position from which to reference image the distance is Δz along the optical axis can be generated by means of Taylor expansion theorem and the calculated different order intensity derivatives. Finally, the microscopic specimen can be reconstructed in 3D form using deconvolution technology and all the images including both the observed images and the generated images. The experimental results show the effectiveness and feasibility of our method.

Comparison of endoscope- versus microscope-assisted resection of deep-seated intracranial lesions using a minimally invasive port retractor system.

PubMed

Hong, Christopher S; Prevedello, Daniel M; Elder, J Bradley

2016-03-01

Tubular brain retractors may improve access to deep-seated brain lesions while potentially reducing the risks of collateral neurological injury associated with standard microsurgical approaches. Here, microscope-assisted resection of lesions using tubular retractors is assessed to determine if it is superior to endoscope-assisted surgery due to the technological advancements associated with modern tubular ports and surgical microscopes. Following institutional approval of the tubular port, data obtained from the initial 20 patients to undergo transportal resection of deep-seated brain lesions were analyzed in this study. The pathological entities of the resected tissues included metastatic tumors (8 patients), glioma (7), meningioma (1), neurocytoma (1), radiation necrosis (1), primitive neuroectodermal tumor (1), and hemangioblastoma (1). Surgery incorporated endoscopic (5 patients) or microscopic (15) assistance. The locations included the basal ganglia (11 patients), cerebellum (4), frontal lobe (2), temporal lobe (2), and parietal lobe (1). Cases were reviewed for neurological outcomes, extent of resection (EOR), and complications. Technical data for the port, surgical microscope, and endoscope were analyzed. EOR was considered total in 14 (70%), near total (> 95%) in 4 (20%), and subtotal (< 90%) in 2 (10%) of 20 patients. Incomplete resection was associated with the basal ganglia location (p < 0.05) and use of the endoscope (p < 0.002). Four of 5 (80%) endoscope-assisted cases were near-total (2) or subtotal (2) resection. Histopathological diagnosis, presenting neurological symptoms, and demographics were not associated with EOR. Complication rates were low and similar between groups. Initial experience with tubular retractors favors use of the microscope rather than the endoscope due to a wider and 3D field of view. Improved microscope optics and tubular retractor design allows for binocular vision with improved lighting for the resection of deep-seated brain lesions.

A nano grating tunable MEMS optical filter for high-speed on-chip multispectral fluorescent detection.

PubMed

Truxal, Steven C; Huang, Nien-Tsu; Kurabayashi, Katsuo

2009-01-01

We report a microelectromechanical (MEMS) tunable optical filter and its integration in a fluorescence microscope for high speed on-chip spectral measurements. This integration allows for measurements of any fluorescence sample placed onto the microscope stage. We demonstrate the system capabilities by taking spectral measurements of multicolor fluorescent beads and fluorescently labeled cells passing through a microfluidic cytometer. The system has applications in biological studies where the measurement of multiple fluorescent peaks is restricted by the detection method's speed and sensitivity.

Electron microscopic and optical studies of prism faces of synthetic quartz

NASA Technical Reports Server (NTRS)

Buzek, B. C.; Vagh, A. S.

1977-01-01

Application of electron and optical microscopic techniques to the study of growth spirals on quartz crystal faces is described. Attention is centered on the centers of the spirals and on screw ledges; overhanging kinks are revealed on one side of the spiral centers. The possibility that these special features may have developed after growth of the crystals went to completion is explored. The conjecture is raised that such structures might result from adsorption of growth-inhibiting impurities at the center of the growth spiral on the quartz habit faces.

Laboratory-size three-dimensional water-window x-ray microscope with Wolter type I mirror optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohsuka, Shinji; The Graduate School for the Creation of New Photonics Industries, 1955-1 Kurematsu-cho, Nishi-ku, Hamamatsu-City, 431-1202; Ohba, Akira

2016-01-28

We constructed a laboratory-size three-dimensional water-window x-ray microscope that combines wide-field transmission x-ray microscopy with tomographic reconstruction techniques. It consists of an electron-impact x-ray source emitting oxygen Kα x-rays, Wolter type I grazing incidence mirror optics, and a back-illuminated CCD for x-ray imaging. A spatial resolution limit better than 1.0 line pairs per micrometer was obtained for two-dimensional transmission images, and 1-μm-scale three-dimensional fine structures were resolved.

Artificial testing targets with controllable blur for adaptive optics microscopes

NASA Astrophysics Data System (ADS)

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

2017-08-01

This letter proposes a method of configuring a testing target to evaluate the performance of adaptive optics microscopes. In this method, a testing slide with fluorescent beads is used to simultaneously determine the point spread function and the field of view. The point spread function is reproduced to simulate actual biological samples by etching a microstructure on the cover glass. The fabrication process is simplified to facilitate an onsite preparation. The artificial tissue consists of solid materials and silicone oil and is stable for use in repetitive experiments.

Fast and Accurate Cell Tracking by a Novel Optical-Digital Hybrid Method

NASA Astrophysics Data System (ADS)

Torres-Cisneros, M.; Aviña-Cervantes, J. G.; Pérez-Careta, E.; Ambriz-Colín, F.; Tinoco, Verónica; Ibarra-Manzano, O. G.; Plascencia-Mora, H.; Aguilera-Gómez, E.; Ibarra-Manzano, M. A.; Guzman-Cabrera, R.; Debeir, Olivier; Sánchez-Mondragón, J. J.

2013-09-01

An innovative methodology to detect and track cells using microscope images enhanced by optical cross-correlation techniques is proposed in this paper. In order to increase the tracking sensibility, image pre-processing has been implemented as a morphological operator on the microscope image. Results show that the pre-processing process allows for additional frames of cell tracking, therefore increasing its robustness. The proposed methodology can be used in analyzing different problems such as mitosis, cell collisions, and cell overlapping, ultimately designed to identify and treat illnesses and malignancies.

Model wavefront sensor for adaptive confocal microscopy

NASA Astrophysics Data System (ADS)

Booth, Martin J.; Neil, Mark A. A.; Wilson, Tony

2000-05-01

A confocal microscope permits 3D imaging of volume objects by the inclusion of a pinhole in the detector path which eliminates out of focus light. This configuration is however very sensitive to aberrations induced by the specimen or the optical system and would therefore benefit from an adaptive optics approach. We present a wavefront sensor capable of measuring directly the Zernike components of an aberrated wavefront and show that it is particularly applicable to the confocal microscope since only those wavefronts originating in the focal region contribute to the measured aberration.

Demonstration of magnetic domain boundary movement using an easily assembled videocam-microscope system

NASA Technical Reports Server (NTRS)

Patterson, John W.

1992-01-01

The objectives are to build and demonstrate a low cost and highly flexible TV microscope facility and then use it to view the motion of magnetic domain boundaries as the local magnetic field is varied. The expense of an optical microscope and the videocam adapters sold for them is largely avoided by using the facility described below. The equipment, supplies, and procedure are presented.

Stereovision-based integrated system for point cloud reconstruction and simulated brain shift validation.

PubMed

Yang, Xiaochen; Clements, Logan W; Luo, Ma; Narasimhan, Saramati; Thompson, Reid C; Dawant, Benoit M; Miga, Michael I

2017-07-01

Intraoperative soft tissue deformation, referred to as brain shift, compromises the application of current image-guided surgery navigation systems in neurosurgery. A computational model driven by sparse data has been proposed as a cost-effective method to compensate for cortical surface and volumetric displacements. We present a mock environment developed to acquire stereoimages from a tracked operating microscope and to reconstruct three-dimensional point clouds from these images. A reconstruction error of 1 mm is estimated by using a phantom with a known geometry and independently measured deformation extent. The microscope is tracked via an attached tracking rigid body that facilitates the recording of the position of the microscope via a commercial optical tracking system as it moves during the procedure. Point clouds, reconstructed under different microscope positions, are registered into the same space to compute the feature displacements. Using our mock craniotomy device, realistic cortical deformations are generated. When comparing our tracked microscope stereo-pair measure of mock vessel displacements to that of the measurement determined by the independent optically tracked stylus marking, the displacement error was [Formula: see text] on average. These results demonstrate the practicality of using tracked stereoscopic microscope as an alternative to laser range scanners to collect sufficient intraoperative information for brain shift correction.

Atmospheric scanning electron microscope observes cells and tissues in open medium through silicon nitride film.

PubMed

Nishiyama, Hidetoshi; Suga, Mitsuo; Ogura, Toshihiko; Maruyama, Yuusuke; Koizumi, Mitsuru; Mio, Kazuhiro; Kitamura, Shinichi; Sato, Chikara

2010-03-01

Direct observation of subcellular structures and their characterization is essential for understanding their physiological functions. To observe them in open environment, we have developed an inverted scanning electron microscope with a detachable, open-culture dish, capable of 8 nm resolution, and combined with a fluorescence microscope quasi-simultaneously observing the same area from the top. For scanning electron microscopy from the bottom, a silicon nitride film window in the base of the dish maintains a vacuum between electron gun and open sample dish while allowing electrons to pass through. Electrons are backscattered from the sample and captured by a detector under the dish. Cells cultured on the open dish can be externally manipulated under optical microscopy, fixed, and observed using scanning electron microscopy. Once fine structures have been revealed by scanning electron microscopy, their component proteins may be identified by comparison with separately prepared fluorescence-labeled optical microscopic images of the candidate proteins, with their heavy-metal-labeled or stained ASEM images. Furthermore, cell nuclei in a tissue block stained with platinum-blue were successfully observed without thin-sectioning, which suggests the applicability of this inverted scanning electron microscope to cancer diagnosis. This microscope visualizes mesoscopic-scale structures, and is also applicable to non-bioscience fields including polymer chemistry. (c) 2010 Elsevier Inc. All rights reserved.

Microscope-integrated optical coherence tomography for image-aided positioning of glaucoma surgery

NASA Astrophysics Data System (ADS)

Li, Xiqi; Wei, Ling; Dong, Xuechuan; Huang, Ping; Zhang, Chun; He, Yi; Shi, Guohua; Zhang, Yudong

2015-07-01

Most glaucoma surgeries involve creating new aqueous outflow pathways with the use of a small surgical instrument. This article reported a microscope-integrated, real-time, high-speed, swept-source optical coherence tomography system (SS-OCT) with a 1310-nm light source for glaucoma surgery. A special mechanism was designed to produce an adjustable system suitable for use in surgery. A two-graphic processing unit architecture was used to speed up the data processing and real-time volumetric rendering. The position of the surgical instrument can be monitored and measured using the microscope and a grid-inserted image of the SS-OCT. Finally, experiments were simulated to assess the effectiveness of this integrated system. Experimental results show that this system is a suitable positioning tool for glaucoma surgery.

A versatile optical microscope for time-dependent single-molecule and single-particle spectroscopy

NASA Astrophysics Data System (ADS)

Li, Hao; Yang, Haw

2018-03-01

This work reports the design and implementation of a multi-function optical microscope for time-dependent spectroscopy on single molecules and single nanoparticles. It integrates the now-routine single-object measurements into one standalone platform so that no reconfiguration is needed when switching between different types of sample or spectroscopy modes. The illumination modes include evanescent field through total internal reflection, dark-field illumination, and epi-excitation onto a diffraction-limited spot suitable for confocal detection. The detection modes include spectrally resolved line imaging, wide-field imaging with dual-color capability, and two-color single-element photon-counting detection. The switch between different spectroscopy and data acquisition modes is fully automated and executed through computer programming. The capability of this microscope is demonstrated through selected proof-of-principle experiments.

Hyperspectral stimulated emission depletion microscopy and methods of use thereof

DOEpatents

Timlin, Jerilyn A; Aaron, Jesse S

2014-04-01

A hyperspectral stimulated emission depletion ("STED") microscope system for high-resolution imaging of samples labeled with multiple fluorophores (e.g., two to ten fluorophores). The hyperspectral STED microscope includes a light source, optical systems configured for generating an excitation light beam and a depletion light beam, optical systems configured for focusing the excitation and depletion light beams on a sample, and systems for collecting and processing data generated by interaction of the excitation and depletion light beams with the sample. Hyperspectral STED data may be analyzed using multivariate curve resolution analysis techniques to deconvolute emission from the multiple fluorophores. The hyperspectral STED microscope described herein can be used for multi-color, subdiffraction imaging of samples (e.g., materials and biological materials) and for analyzing a tissue by Forster Resonance Energy Transfer ("FRET").

A versatile optical microscope for time-dependent single-molecule and single-particle spectroscopy.

PubMed

Li, Hao; Yang, Haw

2018-03-28

This work reports the design and implementation of a multi-function optical microscope for time-dependent spectroscopy on single molecules and single nanoparticles. It integrates the now-routine single-object measurements into one standalone platform so that no reconfiguration is needed when switching between different types of sample or spectroscopy modes. The illumination modes include evanescent field through total internal reflection, dark-field illumination, and epi-excitation onto a diffraction-limited spot suitable for confocal detection. The detection modes include spectrally resolved line imaging, wide-field imaging with dual-color capability, and two-color single-element photon-counting detection. The switch between different spectroscopy and data acquisition modes is fully automated and executed through computer programming. The capability of this microscope is demonstrated through selected proof-of-principle experiments.

Asbestos Testing: Is the EPA Misleading You?

ERIC Educational Resources Information Center

Levins, Hoag

1983-01-01

Experts warn that only electron microscopes can see the smaller fibers of asbestos that are known to cause the most cancers, though the Environmental Protection Agency still endorses optical microscopes for asbestos removal verification. Asbestos testing methods are explained and sources of information are provided. (MLF)

Design and Construction of a Multi-wavelength, Micromirror Total Internal Reflectance Fluorescence Microscope

PubMed Central

Larson, Joshua; Kirk, Matt; Drier, Eric A.; O’Brien, William; MacKay, James F.; Friedman, Larry; Hoskins, Aaron

2015-01-01

Colocalization Single Molecule Spectroscopy (CoSMoS) has proven to be a useful method for studying the composition, kinetics, and mechanisms of complex cellular machines. Key to the technique is the ability to simultaneously monitor multiple proteins and/or nucleic acids as they interact with one another. Here we describe a protocol for constructing a CoSMoS micromirror Total Internal Reflection Fluorescence Microscope (mmTIRFM). Design and construction of a scientific microscope often requires a number of custom components and a significant time commitment. In our protocol, we have streamlined this process by implementation of a commercially available microscopy platform designed to accommodate the optical components necessary for a mmTIRFM. The mmTIRF system eliminates the need for machining custom parts by the end-user and facilitates optical alignment. Depending on the experience-level of the microscope builder, these time-savings and the following protocol can enable mmTIRF construction to be completed within two months. PMID:25188633

Design and construction of a multiwavelength, micromirror total internal reflectance fluorescence microscope.

PubMed

Larson, Joshua; Kirk, Matt; Drier, Eric A; O'Brien, William; MacKay, James F; Friedman, Larry J; Hoskins, Aaron A

2014-10-01

Colocalization single-molecule spectroscopy (CoSMoS) has proven to be a useful method for studying the composition, kinetics and mechanisms of complex cellular machines. Key to the technique is the ability to simultaneously monitor multiple proteins and/or nucleic acids as they interact with one another. Here we describe a protocol for constructing a CoSMoS micromirror total internal reflection fluorescence microscope (mmTIRFM). Design and construction of a scientific microscope often requires a number of custom components and a substantial time commitment. In our protocol, we have streamlined this process by implementation of a commercially available microscopy platform designed to accommodate the optical components necessary for an mmTIRFM. The mmTIRF system eliminates the need for machining custom parts by the end user and facilitates optical alignment. Depending on the experience level of the microscope builder, these time savings and the following protocol can enable mmTIRF construction to be completed within 2 months.

Spatiotemporal focusing-based widefield multiphoton microscopy for fast optical sectioning.

PubMed

Cheng, Li-Chung; Chang, Chia-Yuan; Lin, Chun-Yu; Cho, Keng-Chi; Yen, Wei-Chung; Chang, Nan-Shan; Xu, Chris; Dong, Chen Yuan; Chen, Shean-Jen

2012-04-09

In this study, a microscope based on spatiotemporal focusing offering widefield multiphoton excitation has been developed to provide fast optical sectioning images. Key features of this microscope are the integrations of a 10 kHz repetition rate ultrafast amplifier featuring high instantaneous peak power (maximum 400 μJ/pulse at a 90 fs pulse width) and a TE-cooled, ultra-sensitive photon detecting, electron multiplying charge-coupled camera into a spatiotemporal focusing microscope. This configuration can produce multiphoton images with an excitation area larger than 200 × 100 μm² at a frame rate greater than 100 Hz (current maximum of 200 Hz). Brownian motions of fluorescent microbeads as small as 0.5 μm were observed in real-time with a lateral spatial resolution of less than 0.5 μm and an axial resolution of approximately 3.5 μm. Furthermore, second harmonic images of chicken tendons demonstrate that the developed widefield multiphoton microscope can provide high resolution z-sectioning for bioimaging.

To boldly glow ... applications of laser scanning confocal microscopy in developmental biology.

PubMed

Paddock, S W

1994-05-01

The laser scanning confocal microscope (LSCM) is now established as an invaluable tool in developmental biology for improved light microscope imaging of fluorescently labelled eggs, embryos and developing tissues. The universal application of the LSCM in biomedical research has stimulated improvements to the microscopes themselves and the synthesis of novel probes for imaging biological structures and physiological processes. Moreover the ability of the LSCM to produce an optical series in perfect register has made computer 3-D reconstruction and analysis of light microscope images a practical option.

Electron Optics for Biologists: Physical Origins of Spherical Aberrations

ERIC Educational Resources Information Center

Geissler, Peter; Zadunaisky, Jose

1974-01-01

Reports on the physical origins of spherical aberrations in axially symmetric electrostatic lenses to convey the essentials of electon optics to those who must think critically about the resolution of the electron microscope. (GS)

Applied physics: Optical trapping for space mirrors.

PubMed

McGloin, David

2014-02-27

Might it be possible to create mirrors for space telescopes, using nothing but microscopic particles held in place by light? A study that exploits a technique called optical binding provides a step towards this goal.

Near-field nano-Raman imaging of Si device structures

NASA Astrophysics Data System (ADS)

Atesang, Jacob; Geer, Robert

2005-05-01

Apertureless-based, near-field Raman imaging holds the potential for nanoscale stress metrology in emerging Si devices. Preliminary application of near-field Raman imaging on Si device structures has demonstrated the potential for stress measurements. However, detailed investigations have not been published regarding the effect of tip radius on observed near-field enhancement. Such investigations are important to understand the fundamental limits regarding the signal-to-noise ratio of the measurement and the spatial resolution that can potentially be achieved before wide application to semiconductor metrology can be considered. Investigations are presented into near-field enhancement of Raman scattering from Si device structures using a modified near-field optical microscope (NSOM). The nano-Raman system utilizes an off-axis (45°) backscattering NSOM geometry with free-space collection optics. The spectroscopic configuration utilizes a single-bounce spectrometer incorporating a holographic notch filter assembly utilized as a secondary beam-splitter for an apertureless backscattering collection geometry. Near-field enhancement is observed for both Al- and Ag-coated probes. An inverse square power-law relationship is observed between near-field enhancement factor and tip radius.

High resolution FTIR imaging provides automated discrimination and detection of single malaria parasite infected erythrocytes on glass.

PubMed

Perez-Guaita, David; Andrew, Dean; Heraud, Philip; Beeson, James; Anderson, David; Richards, Jack; Wood, Bayden R

2016-06-23

New highly sensitive tools for malaria diagnostics are urgently needed to enable the detection of infection in asymptomatic carriers and patients with low parasitemia. In pursuit of a highly sensitive diagnostic tool that can identify parasite infections at the single cell level, we have been exploring Fourier transform infrared (FTIR) microscopy using a Focal Plane Array (FPA) imaging detector. Here we report for the first time the application of a new optic configuration developed by Agilent that incorporates 25× condenser and objective Cassegrain optics with a high numerical aperture (NA = 0.81) along with additional high magnification optics within the microscope to provide 0.66 micron pixel resolution (total IR system magnification of 61×) to diagnose malaria parasites at the single cell level on a conventional glass microscope slide. The high quality images clearly resolve the parasite's digestive vacuole demonstrating sub-cellular resolution using this approach. Moreover, we have developed an algorithm that first detects the cells in the infrared image, and secondly extracts the average spectrum. The average spectrum is then run through a model based on Partial Least Squares-Discriminant Analysis (PLS-DA), which diagnoses unequivocally the infected from normal cells. The high quality images, and the fact this measurement can be achieved without a synchrotron source on a conventional glass slide, shows promise as a potential gold standard for malaria detection at the single cell level.

Microscopic theory of optical absorption in graphene enhanced by lattices of plasmonic nanoparticles

NASA Astrophysics Data System (ADS)

Mueller, Niclas S.; Reich, Stephanie

2018-06-01

We present a microscopic description of plasmon-enhanced optical absorption in graphene, which is based on perturbation theory. We consider the interaction of graphene with a lattice of plasmonic nanoparticles, as was previously realized experimentally. By using tight-binding wave functions for the electronic states of graphene and the dipole approximation for the plasmon, we obtain analytic expressions for the coupling matrix element and enhanced optical absorption. The plasmonic nanostructure induces nonvertical optical transitions in the band structure of graphene with selection rules for the momentum transfer that depend on the periodicity of the plasmonic lattice. The plasmon-mediated optical absorption leads to an anisotropic carrier population around the K point in phase space, which depends on the polarization pattern of the plasmonic near field in the graphene plane. Using Fourier optics, we draw a connection to a macroscopic approach, which is independent from graphene-specific parameters. Each Fourier component of the plasmonic near field corresponds to the momentum transfer of an optical transition. Both approaches lead to the same expression for the integrated optical absorption enhancement, which is relevant for the photocurrent enhancement in graphene-based optoelectronic devices.

Optical alignment using a CGH and an autostigmatic microscope

NASA Astrophysics Data System (ADS)

Parks, Robert E.

2017-08-01

We show how custom computer generated holograms (CGH) are used along with an autostigmatic microscope (ASM) to align both optical and mechanical components relative to the CGH. The patterns in the CGHs define points and lines in space when interrogated with the focus of the ASM. Once the ASM is aligned to the CGH, an optical or mechanical component such as a lens, a well-polished ball or a cylinder can be aligned to the ASM in 3 or 4 degrees of freedom and thus to the CGH. In this case we show how a CGH is used to make a fixture for cementing a doublet lens without the need for a rotary table or a precision vertical stage.

Reflective type objective based spectral-domain phase-sensitive optical coherence tomography for high-sensitive structural and functional imaging of cochlear microstructures through intact bone of an excised guinea pig cochlea

NASA Astrophysics Data System (ADS)

Subhash, Hrebesh M.; Wang, Ruikang K.; Chen, Fangyi; Nuttall, Alfred L.

2013-03-01

Most of the optical coherence tomographic (OCT) systems for high resolution imaging of biological specimens are based on refractive type microscope objectives, which are optimized for specific wave length of the optical source. In this study, we present the feasibility of using commercially available reflective type objective for high sensitive and high resolution structural and functional imaging of cochlear microstructures of an excised guinea pig through intact temporal bone. Unlike conventional refractive type microscopic objective, reflective objective are free from chromatic aberrations due to their all-reflecting nature and can support a broadband of spectrum with very high light collection efficiency.

Theoretical model of the helium zone plate microscope

NASA Astrophysics Data System (ADS)

Salvador Palau, Adrià; Bracco, Gianangelo; Holst, Bodil

2017-01-01

Neutral helium microscopy is a new technique currently under development. Its advantages are the low energy, charge neutrality, and inertness of the helium atoms, a potential large depth of field, and the fact that at thermal energies the helium atoms do not penetrate into any solid material. This opens the possibility, among others, for the creation of an instrument that can measure surface topology on the nanoscale, even on surfaces with high aspect ratios. One of the most promising designs for helium microscopy is the zone plate microscope. It consists of a supersonic expansion helium beam collimated by an aperture (skimmer) focused by a Fresnel zone plate onto a sample. The resolution is determined by the focal spot size, which depends on the size of the skimmer, the optics of the system, and the velocity spread of the beam through the chromatic aberrations of the zone plate. An important factor for the optics of the zone plate is the width of the outermost zone, corresponding to the smallest opening in the zone plate. The width of the outermost zone is fabrication limited to around 10 nm with present-day state-of-the-art technology. Due to the high ionization potential of neutral helium atoms, it is difficult to build efficient helium detectors. Therefore, it is crucial to optimize the microscope design to maximize the intensity for a given resolution and width of the outermost zone. Here we present an optimization model for the helium zone plate microscope. Assuming constant resolution and width of the outermost zone, we are able to reduce the problem to a two-variable problem (zone plate radius and object distance) and we show that for a given beam temperature and pressure, there is always a single intensity maximum. We compare our model with the highest-resolution zone plate focusing images published and show that the intensity can be increased seven times. Reducing the width of the outermost zone to 10 nm leads to an increase in intensity of more than 8000 times. Finally, we show that with present-day state-of-the-art detector technology (ionization efficiency 1 ×10-3 ), a resolution of the order of 10 nm is possible. In order to make this quantification, we have assumed a Lambertian reflecting surface and calculated the beam spot size that gives a signal 100 cts/s within a solid angle of 0.02 sr, following an existing helium microscope design.

Aligning Arrays of Lenses and Single-Mode Optical Fibers

NASA Technical Reports Server (NTRS)

Liu, Duncan

2004-01-01

A procedure now under development is intended to enable the precise alignment of sheet arrays of microscopic lenses with the end faces of a coherent bundle of as many as 1,000 single-mode optical fibers packed closely in a regular array (see Figure 1). In the original application that prompted this development, the precise assembly of lenses and optical fibers serves as a single-mode spatial filter for a visible-light nulling interferometer. The precision of alignment must be sufficient to limit any remaining wavefront error to a root-mean-square value of less than 1/10 of a wavelength of light. This wavefront-error limit translates to requirements to (1) ensure uniformity of both the lens and fiber arrays, (2) ensure that the lateral distance from the central axis of each lens and the corresponding optical fiber is no more than a fraction of a micron, (3) angularly align the lens-sheet planes and the fiber-bundle end faces to within a few arc seconds, and (4) axially align the lenses and the fiber-bundle end faces to within tens of microns of the focal distance. Figure 2 depicts the apparatus used in the alignment procedure. The beam of light from a Zygo (or equivalent) interferometer is first compressed by a ratio of 20:1 so that upon its return to the interferometer, the beam will be magnified enough to enable measurement of wavefront quality. The apparatus includes relay lenses that enable imaging of the arrays of microscopic lenses in a charge-coupled-device (CCD) camera that is part of the interferometer. One of the arrays of microscopic lenses is mounted on a 6-axis stage, in proximity to the front face of the bundle of optical fibers. The bundle is mounted on a separate stage. A mirror is attached to the back face of the bundle of optical fibers for retroreflection of light. When a microscopic lens and a fiber are aligned with each other, the affected portion of the light is reflected back by the mirror, recollimated by the microscopic lens, transmitted through the relay lenses and the beam compressor/expander, then split so that half goes to a detector and half to the interferometer. The output of the detector is used as a feedback control signal for the six-axis stage to effect alignment.

Development of an upconverting chelate assay

NASA Astrophysics Data System (ADS)

Xiao, Xudong; Haushalter, Jeanne P.; Kotz, Kenneth T.; Faris, Gregory W.

2005-04-01

We report progress on performing a cell-based assay for the detection of EGFR on cell surfaces by using upconverting chelates. An upconversion microscope has been developed for performing assays and testing optical response. A431 cells are labeled with europium DOTA and imaged using this upconverting microscope.

Optimized optical clearing method for imaging central nervous system

NASA Astrophysics Data System (ADS)

Yu, Tingting; Qi, Yisong; Gong, Hui; Luo, Qingming; Zhu, Dan

2015-03-01

The development of various optical clearing methods provides a great potential for imaging entire central nervous system by combining with multiple-labelling and microscopic imaging techniques. These methods had made certain clearing contributions with respective weaknesses, including tissue deformation, fluorescence quenching, execution complexity and antibody penetration limitation that makes immunostaining of tissue blocks difficult. The passive clarity technique (PACT) bypasses those problems and clears the samples with simple implementation, excellent transparency with fine fluorescence retention, but the passive tissue clearing method needs too long time. In this study, we not only accelerate the clearing speed of brain blocks but also preserve GFP fluorescence well by screening an optimal clearing temperature. The selection of proper temperature will make PACT more applicable, which evidently broaden the application range of this method.

Dependence of the absorption and optical surface plasmon scattering of MoS₂ nanoparticles on aspect ratio, size, and media.

PubMed

Yadgarov, Lena; Choi, Charina L; Sedova, Anastasiya; Cohen, Ayala; Rosentsveig, Rita; Bar-Elli, Omri; Oron, Dan; Dai, Hongjie; Tenne, Reshef

2014-04-22

The optical and electronic properties of suspensions of inorganic fullerene-like nanoparticles of MoS2 are studied through light absorption and zeta-potential measurements and compared to those of the corresponding microscopic platelets. The total extinction measurements show that, in addition to excitonic peaks and the indirect band gap transition, a new peak is observed at 700-800 nm. This spectral peak has not been reported previously for MoS2. Comparison of the total extinction and decoupled absorption spectrum indicates that this peak largely originates from scattering. Furthermore, the dependence of this peak on nanoparticle size, shape, and surface charge, as well as solvent refractive index, suggests that this transition arises from a plasmon resonance.

Cryo diffraction microscopy: Ice conditions and finite supports

DOE PAGES

Miao, H.; Downing, K.; Huang, X.; ...

2009-09-25

Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent brightfield imaging using zone plate optics in a transmission x-ray microscope (TXM), and x-ray diffraction microscopy (XDM) where an image is reconstructed from the far-field coherent diffraction pattern. In XDM one must computationally phase weak diffraction signals; in TXM one suffers signal losses due to the finite numerical aperture and efficiency of the optics. In simulations with objects representing isolated cells such as yeast, we find that XDM has the potential for delivering equivalent resolution imagesmore » using fewer photons. This can be an important advantage for studying radiation-sensitive biological and soft matter specimens.« less

Optical perturbation of atoms in weak localization

NASA Astrophysics Data System (ADS)

Yedjour, A.

2018-01-01

We determine the microscopic transport parameters that are necessary to describe the diffusion process of the atomic gas in optical speckle. We use the self-consistent theory to calculate the self-energy of the atomic gas. We compute the spectral function numerically by an average over disorder realizations in terms of the Greens function. We focus mainly on the behaviour of the energy distribution of the atoms to estimate a correction to the mobility edge. Our results show that the energy distribution of the atoms locates the mobility edge position under the disorder amplitude. This behaviour changes for each disorder parameter. We conclude that the disorder amplitude potential induced modification of the energy distribution of the atoms that plays a major role for the prediction of the mobility edge.

Optical properties of MgF2 nano-composite films dispersed with noble metal nanoparticles synthesized by sol-gel method

NASA Astrophysics Data System (ADS)

Wakaki, Moriaki; Soujima, Nobuaki; Shibuya, Takehisa

2015-03-01

Porous MgF2 films synthesized by a sol-gel method exhibit the lowest refractive index among the dielectric optical materials and are the most useful materials for the anti-reflection coatings. On the other hand, surface plasmon resonance (SPR) absorptions of noble metal nanoparticles in various solid matrices have been extensively studied. New functional materials like a SERS (Surface Enhanced Raman Spectroscopy) tips are expected by synthesizing composite materials between porous MgF2 films featured by the network of MgF2 nanoparticles and noble metal nanoparticles introduced within the network. In this study, fundamental physical properties including morphology and optical properties are characterized for these materials to make clear the potential of the composite system. Composite materials of MgF2 films dispersed with noble metal (Ag, Au) nanoparticles were prepared using the sol-gel technique with various annealing temperatures and densities of noble metal nanoparticles. The structural morphology was analyzed by an X-ray diffractometer (XRD) and a scanning electron microscope (SEM). The size and shape distributions of the metal nanoparticles were observed using a transmission electron microscope (TEM). The optical properties of fabricated composite films were characterized by UV-Vis-NIR and FT-IR spectrophotometers. The absorption spectra due to the surface plasmon resonance (SPR) of the metal nanoparticles were analyzed using the dielectric function considering the effective medium approximation, typically Maxwell-Garnett model. The Raman scattering spectra were also studied to check the enhancement effect of specimen dropped on the MgF2: Ag nano-composite films deposited on Si substrate. Enhancement of the Raman intensity of pyridine solution specimen was observed.

The study of optical properties and proteoglycan content of tendons by PS-OCT

NASA Astrophysics Data System (ADS)

Yang, Ying; Rupani, Asha; Weightman, Alan; Wimpenny, Ian; Bagnaninchi, Pierre; Ahearne, Mark

2011-03-01

Tendons are load-bearing collagenous tissues consisting mainly of type I collagen and various proteoglycans (PGs) including decorin and versican. It is widely accepted that highly orientated collagen fibers in tendons a play critical role for transferring tensile stress and demonstrate birefringent optical properties. However, the influence that proteoglycans have on the optical properties of tendons is yet to be fully elucidated. Tendinopathy (defined as a syndrome of tendon pain, tenderness and swelling that affects the normal function of the tissue) is a common disease associated with sporting injuries or degeneration. PG's are the essential components of the tendon extracellular matrix; changes in their quantities and compositions have been associated with tendinopathy. In this study, polarization sensitive optical coherence tomography (PS-OCT) has been used to reveal the relationship between proteoglycan content/location and birefringent properties of tendons. Tendons dissected from freshly slaughtered chickens were imaged at regular intervals by PS-OCT and polarizing light microscope during the extraction of PGs or glycosaminoglycans using established protocols (guanidine hydrochloride (GuHCl) or proteinase K solution). The macroscopic and microscopic time lapsed images are complimentary; mutually demonstrating that there was a higher concentration of PG's in the outer sheath region than in the fascicles; and the integrity of the sheath affected extraction process and the OCT birefringence bands. Extraction of PGs using GuHCl disturbed the organization of local collagen bundles, which corresponded to a reduction in the frequency of birefringence bands and the band width by PS-OCT. The feature of OCT penetration depth helped us to define the heterogeneous distribution of PG's in tendon, which was complimented by polarizing light microscopy. The results provide new insight of tendon structure and also demonstrate a great potential for using PS-OCT as a diagnostic tool to examine tendon pathology.

Photothermal camera port accessory for microscopic thermal diffusivity imaging

NASA Astrophysics Data System (ADS)

Escola, Facundo Zaldívar; Kunik, Darío; Mingolo, Nelly; Martínez, Oscar Eduardo

2016-06-01

The design of a scanning photothermal accessory is presented, which can be attached to the camera port of commercial microscopes to measure thermal diffusivity maps with micrometer resolution. The device is based on the thermal expansion recovery technique, which measures the defocusing of a probe beam due to the curvature induced by the local heat delivered by a focused pump beam. The beam delivery and collecting optics are built using optical fiber technology, resulting in a robust optical system that provides collinear pump and probe beams without any alignment adjustment necessary. The quasiconfocal configuration for the signal collection using the same optical fiber sets very restrictive conditions on the positioning and alignment of the optical components of the scanning unit, and a detailed discussion of the design equations is presented. The alignment procedure is carefully described, resulting in a system so robust and stable that no further alignment is necessary for the day-to-day use, becoming a tool that can be used for routine quality control, operated by a trained technician.

Photon path distribution and optical responses of turbid media: theoretical analysis based on the microscopic Beer-Lambert law.

PubMed

Tsuchiya, Y

2001-08-01

A concise theoretical treatment has been developed to describe the optical responses of a highly scattering inhomogeneous medium using functions of the photon path distribution (PPD). The treatment is based on the microscopic Beer-Lambert law and has been found to yield a complete set of optical responses by time- and frequency-domain measurements. The PPD is defined for possible photons having a total zigzag pathlength of l between the points of light input and detection. Such a distribution is independent of the absorption properties of the medium and can be uniquely determined for the medium under quantification. Therefore, the PPD can be calculated with an imaginary reference medium having the same optical properties as the medium under quantification except for the absence of absorption. One of the advantages of this method is that the optical responses, the total attenuation, the mean pathlength, etc are expressed by functions of the PPD and the absorption distribution.

Non linear optical investigations of silver nanoparticles synthesised by curcumin reduction

NASA Astrophysics Data System (ADS)

Dhanya, N. P.

2017-11-01

Metal nanoparticles have considerable applications in assorted fields like medicine, biology, photonics, metallurgy etc. Optical applications of Silver nanoparticles are of significant interest among researchers nowadays. In this paper, we report a single step chemical reduction of silver nanoparticles with Curcumin both as a reducing and stabilising agent at room temperature. Structural, plasmonic and non linear optical properties of the prepared nanoparticles are explored using Scanning Electron Microscope, Transmission Electron Microscope, UV absorption spectrometry, Spectroflurometry and Z scan. UV-Vis absorption studies affirm the Surface Plasmon Resonance (SPR) absorption and spectroflurometric studies announce the emission spectrum of the prepared silvernanoparticles at 520 nm. SEM and TEM images uphold the existence of uniform sized, spherical silvernanoparticles. Nonlinear optical studies are accomplished with the open aperture z scan technique in the nanosecond regime. The nonlinearity is in virtue of saturable absorption, two-photon absorption and excited state absorption. The marked nonlinearity and optical limiting of the Curcumin reduced silvernanoparticles enhances its photonic applications.

Optical coherence tomography - principles and applications

NASA Astrophysics Data System (ADS)

Fercher, A. F.; Drexler, W.; Hitzenberger, C. K.; Lasser, T.

2003-02-01

There have been three basic approaches to optical tomography since the early 1980s: diffraction tomography, diffuse optical tomography and optical coherence tomography (OCT). Optical techniques are of particular importance in the medical field, because these techniques promise to be safe and cheap and, in addition, offer a therapeutic potential. Advances in OCT technology have made it possible to apply OCT in a wide variety of applications but medical applications are still dominating. Specific advantages of OCT are its high depth and transversal resolution, the fact, that its depth resolution is decoupled from transverse resolution, high probing depth in scattering media, contact-free and non-invasive operation, and the possibility to create various function dependent image contrasting methods. This report presents the principles of OCT and the state of important OCT applications. OCT synthesises cross-sectional images from a series of laterally adjacent depth-scans. At present OCT is used in three different fields of optical imaging, in macroscopic imaging of structures which can be seen by the naked eye or using weak magnifications, in microscopic imaging using magnifications up to the classical limit of microscopic resolution and in endoscopic imaging, using low and medium magnification. First, OCT techniques, like the reflectometry technique and the dual beam technique were based on time-domain low coherence interferometry depth-scans. Later, Fourier-domain techniques have been developed and led to new imaging schemes. Recently developed parallel OCT schemes eliminate the need for lateral scanning and, therefore, dramatically increase the imaging rate. These schemes use CCD cameras and CMOS detector arrays as photodetectors. Video-rate three-dimensional OCT pictures have been obtained. Modifying interference microscopy techniques has led to high-resolution optical coherence microscopy that achieved sub-micrometre resolution. This report is concluded with a short presentation of important OCT applications. Ophthalmology is, due to the transparent ocular structures, still the main field of OCT application. The first commercial instrument too has been introduced for ophthalmic diagnostics (Carl Zeiss Meditec AG). Advances in using near-infrared light, however, opened the path for OCT imaging in strongly scattering tissues. Today, optical in vivo biopsy is one of the most challenging fields of OCT application. High resolution, high penetration depth, and its potential for functional imaging attribute to OCT an optical biopsy quality, which can be used to assess tissue and cell function and morphology in situ. OCT can already clarify the relevant architectural tissue morphology. For many diseases, however, including cancer in its early stages, higher resolution is necessary. New broad-bandwidth light sources, like photonic crystal fibres and superfluorescent fibre sources, and new contrasting techniques, give access to new sample properties and unmatched sensitivity and resolution.

Neutral red cytotoxicity assays for assessing in vivo carbon nanotube ecotoxicity in mussels--Comparing microscope and microplate methods.

PubMed

Miller, M A; Bankier, C; Al-Shaeri, M A M; Hartl, M G J

2015-12-30

The purpose of the present study was to compare two neutral red retention methods, the more established but very labour-intensive microscope method (NRR) against the more recently developed microplate method (NRU). The intention was to explore whether the sample volume throughput could be increased and potential operator bias avoided. Mussels Mytilus sp. were exposed in vivo to 50, 250 and 500 μg L(-1) single (SWCNTs) or multi-walled carbon nanotubes (MWCNTs). Using the NRR method, SWCNTs and MWCNTs caused concentration dependent decreases in neutral red retention time. However, a concentration dependent decrease in optical density was not observed using the NRU method. We conclude that the NRU method is not sensitive enough to assess carbon nanotube ecotoxicity in vivo in environmentally relevant media, and recommend using the NRR method. Copyright © 2015 Elsevier Ltd. All rights reserved.

In situ investigation of bismuth nanoparticles formation by transmission electron microscope.

PubMed

Liu, Liming; Wang, Honghang; Yi, Zichuan; Deng, Quanrong; Lin, Zhidong; Zhang, Xiaowen

2018-02-01

Bismuth (Bi) nanoparticles are prepared by using NaBi(MoO 4 ) 2 nanosheets in the beam of electrons emitted by transmission electron microscope. The formation and growth of Bi nanoparticles are investigated in situ. The sizes of Bi nanoparticles are confined within the range of 6-10nm by controlling irradiation time. It is also observed that once the diameter of nanoparticles is larger than 10nm, the Bi particles are stable as a result of the immobility of large nanoparticles. In addition, some nanoparticles on the edges form nanorods, which are explained as the result of a coalescence process, if the irradiation period is longer than 10min. The in situ research on Bi nanoparticles facilitates in-depth investigations of the physicochemical behavior and provides more potential applications in various fields such as sensors, catalysts and optical devices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular engineering of chiral colloidal liquid crystals using DNA origami

NASA Astrophysics Data System (ADS)

Siavashpouri, Mahsa; Wachauf, Christian H.; Zakhary, Mark J.; Praetorius, Florian; Dietz, Hendrik; Dogic, Zvonimir

2017-08-01

Establishing precise control over the shape and the interactions of the microscopic building blocks is essential for design of macroscopic soft materials with novel structural, optical and mechanical properties. Here, we demonstrate robust assembly of DNA origami filaments into cholesteric liquid crystals, one-dimensional supramolecular twisted ribbons and two-dimensional colloidal membranes. The exquisite control afforded by the DNA origami technology establishes a quantitative relationship between the microscopic filament structure and the macroscopic cholesteric pitch. Furthermore, it also enables robust assembly of one-dimensional twisted ribbons, which behave as effective supramolecular polymers whose structure and elastic properties can be precisely tuned by controlling the geometry of the elemental building blocks. Our results demonstrate the potential synergy between DNA origami technology and colloidal science, in which the former allows for rapid and robust synthesis of complex particles, and the latter can be used to assemble such particles into bulk materials.

Molecular engineering of chiral colloidal liquid crystals using DNA origami.

PubMed

Siavashpouri, Mahsa; Wachauf, Christian H; Zakhary, Mark J; Praetorius, Florian; Dietz, Hendrik; Dogic, Zvonimir

2017-08-01

Establishing precise control over the shape and the interactions of the microscopic building blocks is essential for design of macroscopic soft materials with novel structural, optical and mechanical properties. Here, we demonstrate robust assembly of DNA origami filaments into cholesteric liquid crystals, one-dimensional supramolecular twisted ribbons and two-dimensional colloidal membranes. The exquisite control afforded by the DNA origami technology establishes a quantitative relationship between the microscopic filament structure and the macroscopic cholesteric pitch. Furthermore, it also enables robust assembly of one-dimensional twisted ribbons, which behave as effective supramolecular polymers whose structure and elastic properties can be precisely tuned by controlling the geometry of the elemental building blocks. Our results demonstrate the potential synergy between DNA origami technology and colloidal science, in which the former allows for rapid and robust synthesis of complex particles, and the latter can be used to assemble such particles into bulk materials.

Sensitivity of Dielectric Properties to Wear Process on Carbon Nanofiber/High-Density Polyethylene Composites.

PubMed

Liu, Tian; Wood, Weston; Zhong, Wei-Hong

2011-12-01

We examined the correlation of wear effects with dielectric properties of carbon nanofibers (CNFs; untreated and organosilane-treated)-reinforced high-density polyethylene (HDPE) composites. Wear testing for the nanocomposites over up to 120 h was carried out, and then, dielectric permittivity and dielectric loss factor of the polymer composites with the increased wear time were studied. Scanning electron microscope and optical microscope observations were made to analyze the microstructure features of the nanocomposites. The results reveal that there exist approximate linear relationships of permittivity with wear coefficient for the nanocomposites. Composites containing silanized CNFs with the sufficiently thick coating exhibited high wear resistance. The change in permittivity was more sensitive to the increased wear coefficient for the nanocomposites with lower wear resistance. This work provides potential for further research on the application of dielectric signals to detect the effects of wear process on lifetime of polymeric materials.

Nonlinear network model analysis of vibrational energy transfer and localisation in the Fenna-Matthews-Olson complex

NASA Astrophysics Data System (ADS)

Morgan, Sarah E.; Cole, Daniel J.; Chin, Alex W.

2016-11-01

Collective protein modes are expected to be important for facilitating energy transfer in the Fenna-Matthews-Olson (FMO) complex of photosynthetic green sulphur bacteria, however to date little work has focussed on the microscopic details of these vibrations. The nonlinear network model (NNM) provides a computationally inexpensive approach to studying vibrational modes at the microscopic level in large protein structures, whilst incorporating anharmonicity in the inter-residue interactions which can influence protein dynamics. We apply the NNM to the entire trimeric FMO complex and find evidence for the existence of nonlinear discrete breather modes. These modes tend to transfer energy to the highly connected core pigments, potentially opening up alternative excitation energy transfer routes through their influence on pigment properties. Incorporating localised modes based on these discrete breathers in the optical spectra calculations for FMO using ab initio site energies and excitonic couplings can substantially improve their agreement with experimental results.

Color-tunable properties of Eu3+- and Dy3+-codoped Y2O3 phosphor particles

PubMed Central

2012-01-01

Rare-earth phosphors are commonly used in display panels, security printing, and fluorescent lamps, and have potential applications in lasers and bioimaging. In the present study, Eu3+- and Dy3+-codoped uniform-shaped Y2O3 submicron particles were prepared using the urea homogeneous precipitation method. The structure and morphology of the resulting particles were characterized by X-ray diffraction, field emission scanning electron microscope, and field emission transmission electron microscope, whereas their optical properties were monitored by photoluminescence spectroscopy. The room-temperature luminescence color emission of the synthesized particles can be tuned from red to yellow by switching the excitation wavelength from 254 to 350 nm. The luminescence intensities of red and yellow emissions could be altered by varying the dopant concentration. Strong quenching was observed at high Eu3+ and Dy3+ concentrations in the Y2O3 host lattice. PMID:23043645

Nano-optical functionality based on local photoisomerization in photochromic single crystal

NASA Astrophysics Data System (ADS)

Nakagomi, Ryo; Uchiyama, Kazuharu; Kubota, Satoru; Hatano, Eri; Uchida, Kingo; Naruse, Makoto; Hori, Hirokazu

2018-01-01

Towards the construction of functional devices and systems using optical near-field processes, we demonstrate the multivalent features in the path-branching phenomena in a photochromic single crystal observed in optical phase change between colorless (1o) and blue-colored (1c) phases that transmits in subwavelength scale over a macroscopic spatial range associated with local mechanical distortions induced. To observe the near-field optical processes of transmission path branching, we have developed a top-to-bottom double-probe scanning near-field optical microscope capable of nanometer-scale correlation measurements by two individually position-controlled probes that face each other sandwiching the photochromic material. We have experimentally confirmed that a local near-field optical excitation applied to one side of the photochromic crystal by a probe tip resulted in characteristic structures of subwavelength scale around 100 nm or less that are observed by the other probe tip located on the opposite side. The structures are different from those resulting from far-field excitations that are quantitively evaluated by autocorrelations. The results suggest that the mechanical distortion caused by the local phase change in the photochromic crystal suppresses the phase change of the neighboring molecules. This new type of optical-near-field-induced local photoisomerization has the potential to allow the construction of functional devices with multivalent properties for natural intelligence.

Digital optical imaging of green fluorescent proteins for tracking vascular gene expression: feasibility study in rabbit and human cell models.

PubMed

Yang, X; Liu, H; Li, D; Zhou, X; Jung, W C; Deans, A E; Cui, Y; Cheng, L

2001-04-01

To investigate the feasibility of using a sensitive digital optical imaging technique to detect green fluorescent protein (GFP) expressed in rabbit vasculature and human arterial smooth muscle cells. A GFP plasmid was transfected into human arterial smooth muscle cells to obtain a GFP-smooth muscle cell solution. This solution was imaged in cell phantoms by using a prototype digital optical imaging system. For in vivo validation, a GFP-lentivirus vector was transfected during surgery into the carotid arteries of two rabbits, and GFP-targeted vessels were harvested for digital optical imaging ex vivo. Optical imaging of cell phantoms resulted in a spatial resolution of 25 microm/pixel. Fluorescent signals were detected as diffusely distributed bright spots. At ex vivo optical imaging of arterial tissues, the average fluorescent signal was significantly higher (P <.05) in GFP-targeted tissues (mean +/- SD, 9,357.3 absolute units of density +/- 1,001.3) than in control tissues (5,633.7 absolute units of density +/- 985.2). Both fluorescence microscopic and immunohistochemical findings confirmed these differences between GFP-targeted and control vessels. The digital optical imaging system was sensitive to GFPs and may potentially provide an in vivo imaging tool to monitor and track vascular gene transfer and expression in experimental investigations.

Improved Scanners for Microscopic Hyperspectral Imaging

NASA Technical Reports Server (NTRS)

Mao, Chengye

2009-01-01

Improved scanners to be incorporated into hyperspectral microscope-based imaging systems have been invented. Heretofore, in microscopic imaging, including spectral imaging, it has been customary to either move the specimen relative to the optical assembly that includes the microscope or else move the entire assembly relative to the specimen. It becomes extremely difficult to control such scanning when submicron translation increments are required, because the high magnification of the microscope enlarges all movements in the specimen image on the focal plane. To overcome this difficulty, in a system based on this invention, no attempt would be made to move either the specimen or the optical assembly. Instead, an objective lens would be moved within the assembly so as to cause translation of the image at the focal plane: the effect would be equivalent to scanning in the focal plane. The upper part of the figure depicts a generic proposed microscope-based hyperspectral imaging system incorporating the invention. The optical assembly of this system would include an objective lens (normally, a microscope objective lens) and a charge-coupled-device (CCD) camera. The objective lens would be mounted on a servomotor-driven translation stage, which would be capable of moving the lens in precisely controlled increments, relative to the camera, parallel to the focal-plane scan axis. The output of the CCD camera would be digitized and fed to a frame grabber in a computer. The computer would store the frame-grabber output for subsequent viewing and/or processing of images. The computer would contain a position-control interface board, through which it would control the servomotor. There are several versions of the invention. An essential feature common to all versions is that the stationary optical subassembly containing the camera would also contain a spatial window, at the focal plane of the objective lens, that would pass only a selected portion of the image. In one version, the window would be a slit, the CCD would contain a one-dimensional array of pixels, and the objective lens would be moved along an axis perpendicular to the slit to spatially scan the image of the specimen in pushbroom fashion. The image built up by scanning in this case would be an ordinary (non-spectral) image. In another version, the optics of which are depicted in the lower part of the figure, the spatial window would be a slit, the CCD would contain a two-dimensional array of pixels, the slit image would be refocused onto the CCD by a relay-lens pair consisting of a collimating and a focusing lens, and a prism-gratingprism optical spectrometer would be placed between the collimating and focusing lenses. Consequently, the image on the CCD would be spatially resolved along the slit axis and spectrally resolved along the axis perpendicular to the slit. As in the first-mentioned version, the objective lens would be moved along an axis perpendicular to the slit to spatially scan the image of the specimen in pushbroom fashion.

Microscope sterility during spine surgery.

PubMed

Bible, Jesse E; O'Neill, Kevin R; Crosby, Colin G; Schoenecker, Jonathan G; McGirt, Matthew J; Devin, Clinton J

2012-04-01

Prospective study. Assess the contamination rates of sterile microscope drapes after spine surgery. The use of the operating microscope has become more prevalent in certain spine procedures, providing superior magnification, visualization, and illumination of the operative field. However, it may represent an additional source of bacterial contamination and increase the risk of developing a postoperative infection. This study included 25 surgical spine cases performed by a single spine surgeon that required the use of the operative microscope. Sterile culture swabs were used to obtain samples from 7 defined locations on the microscope drape after its use during the operation. The undraped technician's console was sampled in each case as a positive control, and an additional 25 microscope drapes were swabbed immediately after they were applied to the microscope to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semiquantitative technique. No growth was observed on any of the 25 negative control drapes. In contrast, 100% of preoperative and 96% of postoperative positive controls demonstrated obvious contamination. In the postoperative group, all 7 sites of evaluation were found to be contaminated with rates of 12% to 44%. Four of the 7 evaluated locations were found to have significant contamination rates compared with negative controls, including the shafts of the optic eyepieces on the main surgeon side (24%, P = 0.022), "forehead" portion on both the main surgeon (24%, P = 0.022) and assistant sides (28%, P = 0.010), and "overhead" portion of the drape (44%, P = 0.0002). Bacterial contamination of the operative microscope was found to be significant after spine surgery. Contamination was more common around the optic eyepieces, likely due to inadvertent touching of unsterile portions. Similarly, all regions above the eyepieces also have a propensity for contamination because of unknown contact with unsterile parts of the surgeon. Therefore, we believe that changing gloves after making adjustments to the optic eyepieces and avoid handling any portion of the drape above the eyepieces may decrease the risks of intraoperative contamination and possibly postoperative infection as well.

Ultra-high resolution water window x ray microscope optics design and analysis

NASA Technical Reports Server (NTRS)

Shealy, David L.; Wang, C.

1993-01-01

This project has been focused on the design and analysis of an ultra-high resolution water window soft-x-ray microscope. These activities have been accomplished by completing two tasks contained in the statement of work of this contract. The new results from this work confirm: (1) that in order to achieve resolutions greater than three times the wavelength of the incident radiation, it will be necessary to use spherical mirror surfaces and to use graded multilayer coatings on the secondary in order to accommodate the large variations of the angle of incidence over the secondary when operating the microscope at numerical apertures of 0.35 or greater; (2) that surface contour errors will have a significant effect on the optical performance of the microscope and must be controlled to a peak-to-valley variation of 50-100 A and a frequency of 8 periods over the surface of a mirror; and (3) that tolerance analysis of the spherical Schwarzschild microscope has been shown that the water window operations will require 2-3 times tighter tolerances to achieve a similar performance of operations with 130 A radiation. These results have been included in a manuscript included in the appendix.

Volumetric bioimaging based on light field microscopy with temporal focusing illumination

NASA Astrophysics Data System (ADS)

Hsu, Feng-Chun; Sie, Yong Da; Lai, Feng-Jie; Chen, Shean-Jen

2018-02-01

Light field technique at a single shot can get the whole volume image of observed sample. Therefore, the original frame rate of the optical system can be taken as the volumetric image rate. For dynamically imaging whole micron-scale biosample, a light field microscope with temporal focusing illumination has been developed. In the light field microscope, the f-number of the microlens array (MLA) is adopted to match that of the objective; hence, the subimages via adjacent lenslets do not overlay each other. A three-dimensional (3D) deconvolution algorithm is utilized to deblur the out-of-focusing part. Conventional light field microscopy (LFM) illuminates whole volume sample even noninteresting parts; nevertheless, whole volume excitation causes even more damage on bio-sample and also increase the background noise from the out of range. Therefore, temporal focusing is integrated into the light field microscope for selecting the illumination volume. Herein, a slit on the back focal plane of the objective is utilized to control the axial excitation confinement for selecting the illumination volume. As a result, the developed light field microscope with the temporal focusing multiphoton illumination (TFMPI) can reconstruct 3D images within the selected volume, and the lateral resolution approaches to the theoretical value. Furthermore, the 3D Brownian motion of two-micron fluorescent beads is observed as the criterion of dynamic sample. With superior signal-to-noise ratio and less damage to tissue, the microscope is potential to provide volumetric imaging for vivo sample.

Spectral staining of tumor tissue by fiber optic FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Salzer, Reiner; Steiner, Gerald; Kano, Angelique; Richter, Tom; Bergmann, Ralf; Rodig, Heike; Johannsen, Bernd; Kobelke, Jens

2003-07-01

Infrared (IR) optical fiber have aroused great interest in recent years because of their potential in in-vivo spectroscopy. This potential includes the ability to be flexible, small and to guide IR light in a very large range of wavelengths. Two types - silver halide and chalcogenide - infrared transmitting fibers are investigated in the detection of a malignant tumor. As a test sample for all types of fibers we used a thin section of an entire rat brain with glioblastoma. The fibers were connected with a common infrared microscope. Maps across the whole tissue section with more than 200 spectra were recorded by moving the sample with an XY stage. Data evaluation was performed using fuzzy c-means cluster analysis (FCM). The silver halide fibers provided excellent results. The tumor was clearly discernible from healthy tissue. Chalcogenide fibers are not suitable to distinguish tumor from normal tissue because the fiber has a very low transmittance in the important fingerprint region.

Elastic scattering and breakup reactions of the exotic nucleus 8B on nuclear targets

NASA Astrophysics Data System (ADS)

Lukyanov, V. K.; Kadrev, D. N.; Antonov, A. N.; Zemlyanaya, E. V.; Lukyanov, K. V.; Gaidarov, M. K.; Spasova, K.

2018-05-01

Microscopic calculations of the optical potentials (OPs) and elastic scattering cross sections of the proton-rich nucleus 8B on 12C, 58Ni and 208Pb targets are presented. The density distributions of 8B obtained within the variational Monte Carlo (VMC) model and the three-cluster model (3CM) are used to construct the optical potentials (OP). The real part of the hybrid OP (ReOP) is calculated using the folding model with the direct and exchange terms included, while the imaginary part (ImOP) is obtained on the base of the high energy approximation (HEA). In addition, the cluster model, in which 8B consists of a proton halo and a 7Be core is applied to calculate the breakup cross sections of 8B on 9Be, 12C and 197Au targets, as well as the momentum distributions of 7Be fragments. A comparison with the available experimental data is made and a good agreement is obtained.

Quantitative phase microscopy via optimized inversion of the phase optical transfer function.

PubMed

Jenkins, Micah H; Gaylord, Thomas K

2015-10-01

Although the field of quantitative phase imaging (QPI) has wide-ranging biomedical applicability, many QPI methods are not well-suited for such applications due to their reliance on coherent illumination and specialized hardware. By contrast, methods utilizing partially coherent illumination have the potential to promote the widespread adoption of QPI due to their compatibility with microscopy, which is ubiquitous in the biomedical community. Described herein is a new defocus-based reconstruction method that utilizes a small number of efficiently sampled micrographs to optimally invert the partially coherent phase optical transfer function under assumptions of weak absorption and slowly varying phase. Simulation results are provided that compare the performance of this method with similar algorithms and demonstrate compatibility with large phase objects. The accuracy of the method is validated experimentally using a microlens array as a test phase object. Lastly, time-lapse images of live adherent cells are obtained with an off-the-shelf microscope, thus demonstrating the new method's potential for extending QPI capability widely in the biomedical community.

Graphene-on-silicon hybrid plasmonic-photonic integrated circuits.

PubMed

Xiao, Ting-Hui; Cheng, Zhenzhou; Goda, Keisuke

2017-06-16

Graphene surface plasmons (GSPs) have shown great potential in biochemical sensing, thermal imaging, and optoelectronics. To excite GSPs, several methods based on the near-field optical microscope and graphene nanostructures have been developed in the past few years. However, these methods suffer from their bulky setups and low GSP-excitation efficiency due to the short interaction length between free-space vertical excitation light and the atomic layer of graphene. Here we present a CMOS-compatible design of graphene-on-silicon hybrid plasmonic-photonic integrated circuits that achieve the in-plane excitation of GSP polaritons as well as localized surface plasmon (SP) resonance. By employing a suspended membrane slot waveguide, our design is able to excite GSP polaritons on a chip. Moreover, by utilizing a graphene nanoribbon array, we engineer the transmission spectrum of the waveguide by excitation of localized SP resonance. Our theoretical and computational study paves a new avenue to enable, modulate, and monitor GSPs on a chip, potentially applicable for the development of on-chip electro-optic devices.

When the fl# Is Not the fl#.

ERIC Educational Resources Information Center

Biermann, Mark L.; Biermann, Lois A. A.

1996-01-01

Discusses descriptions of the way in which an optical system controls the quantity of light that reaches a point on the image plane, a basic feature of optical imaging systems such as cameras, telescopes, and microscopes. (JRH)

Field of view advantage of conjugate adaptive optics in microscopy applications

PubMed Central

Mertz, Jerome; Paudel, Hari; Bifano, Thomas G.

2015-01-01

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 astronomy community, our goal here is to recast it specifically for the optical microscopy community. PMID:25967343

Vapor-condensation-assisted optical microscopy for ultralong carbon nanotubes and other nanostructures.

PubMed

Wang, Jiangtao; Li, Tianyi; Xia, Bingyu; Jin, Xiang; Wei, Haoming; Wu, Wenyun; Wei, Yang; Wang, Jiaping; Liu, Peng; Zhang, Lina; Li, Qunqing; Fan, Shoushan; Jiang, Kaili

2014-06-11

Here we present a simple yet powerful approach for the imaging of nanostructures under an optical microscope with the help of vapor condensation on their surfaces. Supersaturated water vapor will first form a nanometer-sized water droplet on the condensation nuclei on the surface of nanostructures, and then the water droplet will grow bigger and scatter more light to make the outline of the nanostructure be visible under dark-field optical microscope. This vapor-condensation-assisted (VCA) optical microscopy is applicable to a variety of nanostructures from ultralong carbon nanotubes to functional groups, generating images with contrast coming from the difference in density of the condensation sites, and does not induce any impurities to the specimens. Moreover, this low-cost and efficient technique can be conveniently integrated with other facilities, such as Raman spectroscope and so forth, which will pave the way for widespread applications.

Fabrication of bright and thin Zn₂SiO₄ luminescent film for electron beam excitation-assisted optical microscope.

PubMed

Furukawa, Taichi; Kanamori, Satoshi; Fukuta, Masahiro; Nawa, Yasunori; Kominami, Hiroko; Nakanishi, Yoichiro; Sugita, Atsushi; Inami, Wataru; Kawata, Yoshimasa

2015-07-13

We fabricated a bright and thin Zn₂SiO₄ luminescent film to serve as a nanometric light source for high-spatial-resolution optical microscopy based on electron beam excitation. The Zn₂SiO₄ luminescent thin film was fabricated by annealing a ZnO film on a Si₃N₄ substrate at 1000 °C in N₂. The annealed film emitted bright cathodoluminescence compared with the as-deposited film. The film is promising for nano-imaging with electron beam excitation-assisted optical microscopy. We evaluated the spatial resolution of a microscope developed using this Zn₂SiO₄ luminescent thin film. This is the first report of the investigation and application of ZnO/Si₃N₄ annealed at a high temperature (1000 °C). The fabricated Zn₂SiO₄ film is expected to enable high-frame-rate dynamic observation with ultra-high resolution using our electron beam excitation-assisted optical microscopy.

Laser beam coupling into nerve fiber myelin allows one to assess its structural membrane properties

NASA Astrophysics Data System (ADS)

Kutuzov, Nikolay P.; Brazhe, Alexey R.; Lyaskovskiy, Vladimir L.; Maksimov, Georgy V.

2015-05-01

We show that myelin, the insulation wrap of nerve fibers, can couple laser light, thus behaving as a single-cell optical device. The effect was employed to map distinct myelin regions based on the coupling efficiency. Raman spectra acquisition allowed us to simultaneously understand the underlying microscopic differences in the membrane lipid ordering degree. The described method potentially provides new capabilities in myelin-associated disease studies and can be used as a handy tool for myelin structure investigation in combination with other methods.

Proton scattering on 40S

NASA Astrophysics Data System (ADS)

Maréchal, F.; Suomijärvi, T.; Blumenfeld, Y.; Azhari, A.; Bazin, D.; Brown, J. A.; Cottle, P. D.; Fauerbach, M.; Glasmacher, T.; Hirzebruch, S. E.; Jewell, J. K.; Kemper, K. W.; Mantica, P. F.; Morrissey, D. J.; Riley, L. A.; Scarpaci, J. A.; Steiner, M.

1998-12-01

We have recently studied the structure of the neutron rich sulfur isotope 40S by using elastic and inelastic proton scattering in inverse kinematics. Optical potential and folding model calculations are compared with the elastic and inelastic angular distributions. Using coupled-channel calculations, the β2 value for the 21+ excited state is determined to be 0.35±0.05. The extracted value of Mn/Mp ratio indicates a small isovector contribution to the 21+ state of 40S. The microscopic analysis of the data is compatible with the presence of a neutron skin for this nucleus.

The research progress of metrological 248nm deep ultraviolent microscope inspection device

NASA Astrophysics Data System (ADS)

Wang, Zhi-xin; Li, Qi; Gao, Si-tian; Shi, Yu-shu; Li, Wei; Li, Shi

2016-01-01

In lithography process, the precision of wafer pattern to a large extent depends on the geometric dimensioning and tolerance of photomasks when accuracy of lithography aligner is certain. Since the minimum linewidth (Critical Dimension) of the aligner exposing shrinks to a few tens of nanometers in size, one-tenth of tolerance errors in fabrication may lead to microchip function failure, so it is very important to calibrate these errors of photomasks. Among different error measurement instruments, deep ultraviolent (DUV) microscope because of its high resolution, as well as its advantages compared to scanning probe microscope restrained by measuring range and scanning electron microscope restrained by vacuum environment, makes itself the most suitable apparatus. But currently there is very few DUV microscope adopting 248nm optical system, means it can attain 80nm resolution; furthermore, there is almost no DUV microscope possessing traceable calibration capability. For these reason, the National Institute of Metrology, China is developing a metrological 248nm DUV microscope mainly consists of DUV microscopic components, PZT and air supporting stages as well as interferometer calibration framework. In DUV microscopic component, the Köhler high aperture transmit condenser, DUV splitting optical elements and PMT pinhole scanning elements are built. In PZT and air supporting stages, a novel PZT actuating flexural hinge stage nested separate X, Y direction kinematics and a friction wheel driving long range air supporting stage are researched. In interferometer framework, a heterodyne multi-pass interferometer measures XY axis translation and Z axis rotation through Zerodur mirror mounted on stage. It is expected the apparatus has the capability to calibrate one dimensional linewidths and two dimensional pitches ranging from 200nm to 50μm with expanded uncertainty below 20nm.

Highest Resolution Image of Dust and Sand Yet Acquired on Mars

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] Click on image for Figure 1Click on image for Figure 2Click on image for Figure 3

This mosaic of four side-by-side microscope images (one a color composite) was acquired by the Optical Microscope, a part of the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument suite on NASA's Phoenix Mars Lander. Taken on the ninth Martian day of the mission, or Sol 9 (June 3, 2008), the image shows a 3 millimeter (0.12 inch) diameter silicone target after it has been exposed to dust kicked up by the landing. It is the highest resolution image of dust and sand ever acquired on Mars. The silicone substrate provides a sticky surface for holding the particles to be examined by the microscope.

Martian Particles on Microscope's Silicone Substrate In figure 1, the particles are on a silcone substrate target 3 millimeters (0.12 inch) in diameter, which provides a sticky surface for holding the particles while the microscope images them. Blow-ups of four of the larger particles are shown in the center. These particles range in size from about 30 microns to 150 microns (from about one one-thousandth of an inch to six one-thousandths of an inch).

Possible Nature of Particles Viewed by Mars Lander's Optical Microscope In figure 2, the color composite on the right was acquired to examine dust that had fallen onto an exposed surface. The translucent particle highlighted at bottom center is of comparable size to white particles in a Martian soil sample (upper pictures) seen two sols earlier inside the scoop of Phoenix's Robotic Arm as imaged by the lander's Robotic Arm Camera. The white particles may be examples of the abundant salts that have been found in the Martian soil by previous missions. Further investigations will be needed to determine the white material's composition and whether translucent particles like the one in this microscopic image are found in Martian soil samples.

Scale of Phoenix Optical Microscope Images This set of pictures in figure 3 gives context for the size of individual images from the Optical Microscope on NASA's Mars Phoenix Lander.

The picture in the upper left was taken on Mars by the Surface Stereo Imager on Phoenix. It shows a portion of the microscope's sample stage exposed to accept a sample. In this case, the sample was of dust kicked up by the spacecraft thrusters during landers. Later samples will include soil delivered by the Robotic Arm.

The other pictures were taken on Earth. They show close-ups of circular substrates on which the microscopic samples rest when the microscope images them. Each circular substrate target is 3 millimeters (about one-tenth of an inch) in diameter. Each image taken by the microscope covers and area 2 millimeters by 1 millimeter (0.08 inch by 0.04 inch), the size of a large grain of sand.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

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.

Optically sectioned in vivo imaging with speckle illumination HiLo microscopy

PubMed Central

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. PMID:21280920

Optically sectioned in vivo imaging with speckle illumination HiLo microscopy.

PubMed

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.

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.

Thermal radiation scanning tunnelling microscopy

NASA Astrophysics Data System (ADS)

de Wilde, Yannick; Formanek, Florian; Carminati, Rémi; Gralak, Boris; Lemoine, Paul-Arthur; Joulain, Karl; Mulet, Jean-Philippe; Chen, Yong; Greffet, Jean-Jacques

2006-12-01

In standard near-field scanning optical microscopy (NSOM), a subwavelength probe acts as an optical `stethoscope' to map the near field produced at the sample surface by external illumination. This technique has been applied using visible, infrared, terahertz and gigahertz radiation to illuminate the sample, providing a resolution well beyond the diffraction limit. NSOM is well suited to study surface waves such as surface plasmons or surface-phonon polaritons. Using an aperture NSOM with visible laser illumination, a near-field interference pattern around a corral structure has been observed, whose features were similar to the scanning tunnelling microscope image of the electronic waves in a quantum corral. Here we describe an infrared NSOM that operates without any external illumination: it is a near-field analogue of a night-vision camera, making use of the thermal infrared evanescent fields emitted by the surface, and behaves as an optical scanning tunnelling microscope. We therefore term this instrument a `thermal radiation scanning tunnelling microscope' (TRSTM). We show the first TRSTM images of thermally excited surface plasmons, and demonstrate spatial coherence effects in near-field thermal emission.

Miniature fiber optic spectrometer-based quantitative fluorescence resonance energy transfer measurement in single living cells.

PubMed

Chai, Liuying; Zhang, Jianwei; Zhang, Lili; Chen, Tongsheng

2015-03-01

Spectral measurement of fluorescence resonance energy transfer (FRET), spFRET, is a widely used FRET quantification method in living cells today. We set up a spectrometer-microscope platform that consists of a miniature fiber optic spectrometer and a widefield fluorescence microscope for the spectral measurement of absolute FRET efficiency (E) and acceptor-to-donor concentration ratio (R(C)) in single living cells. The microscope was used for guiding cells and the spectra were simultaneously detected by the miniature fiber optic spectrometer. Moreover, our platform has independent excitation and emission controllers, so different excitations can share the same emission channel. In addition, we developed a modified spectral FRET quantification method (mlux-FRET) for the multiple donors and multiple acceptors FRET construct (mD∼nA) sample, and we also developed a spectra-based 2-channel acceptor-sensitized FRET quantification method (spE-FRET). We implemented these modified FRET quantification methods on our platform to measure the absolute E and R(C) values of tandem constructs with different acceptor/donor stoichiometries in single living Huh-7 cells.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miranda, Adelaide; De Beule, Pieter A. A., E-mail: pieter.de-beule@inl.int; Martins, Marco

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 discussmore » 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.« less

Use of indocyanine green angiography in microsurgical subinguinal varicocelectomy - lessons learned from our initial experience.

PubMed

Cho, Chak-Lam; Ho, Kwan-Lun; Chan, Wayne Kwun-Wai; Chu, Ringo Wing-Hong; Law, In-Chak

2017-01-01

Microsurgical subinguinal varicocelectomy (MSV) is generally considered the gold standard nowadays in view of the lower risk of complications and recurrence. To achieve complete ligation of veins while preserving testicular artery (TA) during the procedure remains challenging despite the application of high power optical magnification and micro-Doppler ultrasonography. The use of intraoperative indocyanine green angiography (ICGA) with infrared fluorescence operative micro-scope in MSV potentially lowers the incidence of TA injury and shortens the learning curve of nov-ice surgeons. We present our initial experience in the application of the technique in nine patients and explore the potential of the new adjunct. Copyright® by the International Brazilian Journal of Urology.

Creating and Probing Graphene Electron Optics with Local Scanning Probes

NASA Astrophysics Data System (ADS)

Stroscio, Joseph

Ballistic propagation and the light-like dispersion of graphene charge carriers make graphene an attractive platform for optics-inspired graphene electronics where gate tunable potentials can control electron refraction and transmission. In analogy to optical wave propagation in lenses, mirrors and metamaterials, gate potentials can be used to create a negative index of refraction for Veselago lensing and Fabry-Pérot interferometers. In circular geometries, gate potentials can induce whispering gallery modes (WGM), similar to optical and acoustic whispering galleries albeit on a much smaller length scale. Klein scattering of Dirac carriers plays a central role in determining the coherent propagation of electron waves in these resonators. In this talk, I examine the probing of electron resonators in graphene confined by linear and circular gate potentials with the scanning tunneling microscope (STM). The tip in the STM tunnel junction serves both as a tunable local gate potential, and as a probe of the graphene states through tunneling spectroscopy. A combination of a back gate potential, Vg, and tip potential, Vb, creates and controls a circular pn junction that confines the WGM graphene states. The resonances are observed in two separate channels in the tunneling spectroscopy experiment: first, by directly tunneling into the state at the bias energy eVb, and, second, by tunneling from the resonance at the Fermi level as the state is gated by the tip potential. The second channel produces a fan-like set of WGM peaks, reminiscent of the fringes seen in planar geometries by transport measurements. The WGM resonances split in a small applied magnetic field, with a large energy splitting approaching the WGM spacing at 0.5 T. These results agree well with recent theory on Klein scattering in graphene electron resonators. This work is done in collaboration with Y. Zhao, J. Wyrick, F.D. Natterer, J. F. Rodriquez-Nieva, C. Lewandoswski, K. Watanabe, T. Taniguchi, N. B. Zhitenev, and L. S. Levitov.

Chronic monitoring of cortical hemodynamics in behaving, freely-moving rats using a miniaturized head-mounted optical microscope

NASA Astrophysics Data System (ADS)

Sigal, Iliya; Gad, Raanan; Koletar, Margaret; Ringuette, Dene; Stefanovic, Bojana; Levi, Ofer

2016-03-01

Growing interest within the neurophysiology community in assessing healthy and pathological brain activity in animals that are awake and freely-behaving has triggered the need for optical systems that are suitable for such longitudinal studies. In this work we report label-free multi-modal imaging of cortical hemodynamics in the somatosensory cortex of awake, freely-behaving rats, using a novel head-mounted miniature optical microscope. The microscope employs vertical cavity surface emitting lasers (VCSELs) at three distinct wavelengths (680 nm, 795 nm, and 850 nm) to provide measurements of four hemodynamic markers: blood flow speeds, HbO, HbR, and total Hb concentration, across a > 2 mm field of view. Blood flow speeds are extracted using Laser Speckle Contrast Imaging (LSCI), while oxygenation measurements are performed using Intrinsic Optical Signal Imaging (IOSI). Longitudinal measurements on the same animal are made possible over the course of > 6 weeks using a chronic window that is surgically implanted into the skull. We use the device to examine changes in blood flow and blood oxygenation in superficial cortical blood vessels and tissue in response to drug-induced absence-like seizures, correlating motor behavior with changes in blood flow and blood oxygenation in the brain.

Quantitative high dynamic range beam profiling for fluorescence microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell, T. J., E-mail: t.j.mitchell@dur.ac.uk; Saunter, C. D.; O’Nions, W.

2014-10-15

Modern developmental biology relies on optically sectioning fluorescence microscope techniques to produce non-destructive in vivo images of developing specimens at high resolution in three dimensions. As optimal performance of these techniques is reliant on the three-dimensional (3D) intensity profile of the illumination employed, the ability to directly record and analyze these profiles is of great use to the fluorescence microscopist or instrument builder. Though excitation beam profiles can be measured indirectly using a sample of fluorescent beads and recording the emission along the microscope detection path, we demonstrate an alternative approach where a miniature camera sensor is used directly withinmore » the illumination beam. Measurements taken using our approach are solely concerned with the illumination optics as the detection optics are not involved. We present a miniature beam profiling device and high dynamic range flux reconstruction algorithm that together are capable of accurately reproducing quantitative 3D flux maps over a large focal volume. Performance of this beam profiling system is verified within an optical test bench and demonstrated for fluorescence microscopy by profiling the low NA illumination beam of a single plane illumination microscope. The generality and success of this approach showcases a widely flexible beam amplitude diagnostic tool for use within the life sciences.« less

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.

Real-time restoration of white-light confocal microscope optical sections

PubMed Central

Balasubramanian, Madhusudhanan; Iyengar, S. Sitharama; Beuerman, Roger W.; Reynaud, Juan; Wolenski, Peter

2009-01-01

Confocal microscopes (CM) are routinely used for building 3-D images of microscopic structures. Nonideal imaging conditions in a white-light CM introduce additive noise and blur. The optical section images need to be restored prior to quantitative analysis. We present an adaptive noise filtering technique using Karhunen–Loéve expansion (KLE) by the method of snapshots and a ringing metric to quantify the ringing artifacts introduced in the images restored at various iterations of iterative Lucy–Richardson deconvolution algorithm. The KLE provides a set of basis functions that comprise the optimal linear basis for an ensemble of empirical observations. We show that most of the noise in the scene can be removed by reconstructing the images using the KLE basis vector with the largest eigenvalue. The prefiltering scheme presented is faster and does not require prior knowledge about image noise. Optical sections processed using the KLE prefilter can be restored using a simple inverse restoration algorithm; thus, the methodology is suitable for real-time image restoration applications. The KLE image prefilter outperforms the temporal-average prefilter in restoring CM optical sections. The ringing metric developed uses simple binary morphological operations to quantify the ringing artifacts and confirms with the visual observation of ringing artifacts in the restored images. PMID:20186290

Multiscale Imaging of the Mouse Cortex Using Two-Photon Microscopy and Wide-Field Illumination

NASA Astrophysics Data System (ADS)

Bumstead, Jonathan R.

The mouse brain can be studied over vast spatial scales ranging from microscopic imaging of single neurons to macroscopic measurements of hemodynamics acquired over the majority of the mouse cortex. However, most neuroimaging modalities are limited by a fundamental trade-off between the spatial resolution and the field-of-view (FOV) over which the brain can be imaged, making it difficult to fully understand the functional and structural architecture of the healthy mouse brain and its disruption in disease. My dissertation has focused on developing multiscale optical systems capable of imaging the mouse brain at both microscopic and mesoscopic spatial scales, specifically addressing the difference in spatial scales imaged with two-photon microscopy (TPM) and optical intrinsic signal imaging (OISI). Central to this work has been the formulation of a principled design strategy for extending the FOV of the two-photon microscope. Using this design approach, we constructed a TPM system with subcellular resolution and a FOV area 100 times greater than a conventional two-photon microscope. To image the ellipsoidal shape of the mouse cortex, we also developed the microscope to image arbitrary surfaces within a single frame using an electrically tunable lens. Finally, to address the speed limitations of the TPM systems developed during my dissertation, I also conducted research in large-scale neural phenomena occurring in the mouse brain imaged with high-speed OISI. The work conducted during my dissertation addresses some of the fundamental principles in designing and applying optical systems for multiscale imaging of the mouse brain.

Images from Phoenix's MECA Instruments

NASA Technical Reports Server (NTRS)

2008-01-01

The image on the upper left is from NASA's Phoenix Mars Lander's Optical Microscope after a sample informally called 'Sorceress' was delivered to its silicon substrate on the 38th Martian day, or sol, of the mission (July 2, 2008).

A 3D representation of the same sample is on the right, as seen by Phoenix's Atomic Force Microscope. This is 200 times greater magnification than the view from the Optical Microscope, and the most highly magnified image ever seen from another world.

The image shows four round pits, only 5 microns in depth, that were micromachined into the silicon substrate, which is the background plane shown in red. This image has been processed to reflect the levelness of the substrate.

A Martian particle only one micrometer, or one millionth of a meter, across is held in the upper left pit.

The rounded particle shown at the highest magnification ever seen from another world is a particle of the dust that cloaks Mars. Such dust particles color the Martian sky pink, feed storms that regularly envelop the planet and produce Mars' distinctive red soil.

The Optical Microscope and the Atomic Force Microscope are part of Phoenix's Microscopy, Electrochemistry and Conductivity Analyzer instrument.

The AFM was developed by a Swiss-led consortium, with Imperial College London producing the silicon substrate that holds sampled particles.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Making a Microscope with Readily Available Materials

ERIC Educational Resources Information Center

Vannoni, Maurizio; Buah-Bassuah, Paul K.; Molesini, Giuseppe

2007-01-01

The making of microscope devices using inexpensive or recovered materials is demonstrated. Examples of images illustrating the performance of such devices are presented. As a project at the undergraduate level, the task is effective in acquiring familiarity with optical imaging concepts and their practical implementation in the laboratory.…

Image Analysis, Microscopic, and Spectrochemical Study of the PVC Dry Blending Process,

DTIC Science & Technology

The dry blending process used in the production of electrical grade pvc formulations has been studies using a combination of image analysis , microscopic...by image analysis techniques. Optical and scanning electron microscopy were used to assess morphological differences. Spectrochemical techniques were used to indicate chemical changes.

Integrated system for point cloud reconstruction and simulated brain shift validation using tracked surgical microscope

NASA Astrophysics Data System (ADS)

Yang, Xiaochen; Clements, Logan W.; Luo, Ma; Narasimhan, Saramati; Thompson, Reid C.; Dawant, Benoit M.; Miga, Michael I.

2017-03-01

Intra-operative soft tissue deformation, referred to as brain shift, compromises the application of current imageguided surgery (IGS) navigation systems in neurosurgery. A computational model driven by sparse data has been used as a cost effective method to compensate for cortical surface and volumetric displacements. Stereoscopic microscopes and laser range scanners (LRS) are the two most investigated sparse intra-operative imaging modalities for driving these systems. However, integrating these devices in the clinical workflow to facilitate development and evaluation requires developing systems that easily permit data acquisition and processing. In this work we present a mock environment developed to acquire stereo images from a tracked operating microscope and to reconstruct 3D point clouds from these images. A reconstruction error of 1 mm is estimated by using a phantom with a known geometry and independently measured deformation extent. The microscope is tracked via an attached tracking rigid body that facilitates the recording of the position of the microscope via a commercial optical tracking system as it moves during the procedure. Point clouds, reconstructed under different microscope positions, are registered into the same space in order to compute the feature displacements. Using our mock craniotomy device, realistic cortical deformations are generated. Our experimental results report approximately 2mm average displacement error compared with the optical tracking system. These results demonstrate the practicality of using tracked stereoscopic microscope as an alternative to LRS to collect sufficient intraoperative information for brain shift correction.

A laboratory 8 keV transmission full-field x-ray microscope with a polycapillary as condenser for bright and dark field imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumbach, S., E-mail: baumbach@rheinahrcampus.de; Wilhein, T.; Kanngießer, B.

2015-08-15

This article introduces a laboratory setup of a transmission full-field x-ray microscope at 8 keV photon energy. The microscope operates in bright and dark field imaging mode with a maximum field of view of 50 μm. Since the illumination geometry determines whether the sample is illuminated homogeneously and moreover, if different imaging methods can be applied, the condenser optic is one of the most significant parts. With a new type of x-ray condenser, a polycapillary optic, we realized bright field imaging and for the first time dark field imaging at 8 keV photon energy in a laboratory setup. A detectormore » limited spatial resolution of 210 nm is measured on x-ray images of Siemens star test patterns.« less

Fabrication and characterization of novel microsphere-embedded optical devices for enhancing microscopy resolution

NASA Astrophysics Data System (ADS)

Darafsheh, Arash

2018-02-01

Microsphere-assisted imaging can be incorporated onto conventional light microscopes allowing wide-field and flourescence imaging with enhanced resolution. We demonstrated that imaging of specimens containing subdiffraction-limited features is achievable through high-index microspheres embedded in a transparent thin film placed over the specimen. We fabricated novel microsphere-embedded microscope slides composed of barium titanate glass microspheres (with diameter 10-100 μm and refractive index 1.9-2.2) embedded in a transparent polydimethylsiloxane (PDMS) elastomer layer with controllable thickness. We characterized the imaging performance of such microsphere-embedded devices in white-light microscopies, by measuring the imaging resolution, field-of-view, and magnification as a function of microsphere size. Our results inform on the design of novel optical devices, such as microsphere-embedded microscope slides for imaging applications.

Optomechanical design and tolerance of a microscope objective at 121.6 nm

NASA Astrophysics Data System (ADS)

Keyes, Derek S.; Jota, Thiago S.; Gao, Weichuan; Luepke, Dakota; Densmore, Victor; Kim, Young-Sik; Kim, Gun-Hee; Milster, Thomas D.

2015-08-01

By utilizing the Hydrogen-Lyman-α (HLA) source at 121.6 nm, we hope to achieve an intrinsic resolution of 247 nm at 0.3 numerical aperture (NA) and 92 nm at 0.8 NA. The motivation for 121.6 nm microscopy is the existence of a transparent window in the air absorption spectrum at that wavelength, which allows for the sample to be in air while the microscope is in an enclosed nitrogen environment. The microscope objective consists of two reflective optics and a LiF window, and it has been designed to demonstrate diffraction limited performance over a 160μm full field at 121.6 nm. The optomechanical design consists of mechanical subcells for each optical component, precision spacers and a barrel bore, which allow for submicron control of tolerance parameters.

A laboratory 8 keV transmission full-field x-ray microscope with a polycapillary as condenser for bright and dark field imaging.

PubMed

Baumbach, S; Kanngießer, B; Malzer, W; Stiel, H; Wilhein, T

2015-08-01

This article introduces a laboratory setup of a transmission full-field x-ray microscope at 8 keV photon energy. The microscope operates in bright and dark field imaging mode with a maximum field of view of 50 μm. Since the illumination geometry determines whether the sample is illuminated homogeneously and moreover, if different imaging methods can be applied, the condenser optic is one of the most significant parts. With a new type of x-ray condenser, a polycapillary optic, we realized bright field imaging and for the first time dark field imaging at 8 keV photon energy in a laboratory setup. A detector limited spatial resolution of 210 nm is measured on x-ray images of Siemens star test patterns.

Interferometric scanning optical microscope for surface characterization.

PubMed

Offside, M J; Somekh, M G

1992-11-01

A phase-sensitive scanning optical microscope is described that can measure surface height changes down to 0.1 nm. This is achieved by using two heterodyne Michelson interferometers in parallel. One interferometer probes the sample with a tightly focused beam, and the second has a collimated beam that illuminates a large area of the surface, providing a large area on sample reference. This is facilitated by using a specially constructed objective lens that permits the relative areas illuminated by the two probe beams to be varied both arbitrarily and independently, thus ensuring an accurate absolute phase measurement. We subtracted the phase outputs from each interferometer to provide the sample phase information, canceling the phase noise resulting from microphonics in the process. Results from a prototype version of the microscope are presented that demonstrate the advantages of the system over existing techniques.

Optical characterization and bandgap engineering of flat and wrinkle-textured FA0.83Cs0.17Pb(I1-xBrx)3 perovskite thin films

NASA Astrophysics Data System (ADS)

Tejada, A.; Braunger, S.; Korte, L.; Albrecht, S.; Rech, B.; Guerra, J. A.

2018-05-01

The complex refractive indices of formamidinium cesium lead mixed-halide [FA0.83Cs0.17Pb(I1- xBrx)3] perovskite thin films of compositions ranging from x = 0 to 0.4, with both flat and wrinkle-textured surface topographies, are reported. The films are characterized using a combination of variable angle spectroscopic ellipsometry and spectral transmittance in the wavelength range of 190 nm to 850 nm. Optical constants, film thicknesses and roughness layers are obtained point-by-point by minimizing a global error function, without using optical dispersion models, and including topographical information supplied by a laser confocal microscope. To evaluate the bandgap engineering potential of the material, the optical bandgaps and Urbach energies are then accurately determined by applying a band fluctuation model for direct semiconductors, which considers both the Urbach tail and the fundamental band-to-band absorption region in a single equation. With this information, the composition yielding the optimum bandgap of 1.75 eV for a Si-perovskite tandem solar cell is determined.

Developments in optical modeling methods for metrology

NASA Astrophysics Data System (ADS)

Davidson, Mark P.

1999-06-01

Despite the fact that in recent years the scanning electron microscope has come to dominate the linewidth measurement application for wafer manufacturing, there are still many applications for optical metrology and alignment. These include mask metrology, stepper alignment, and overlay metrology. Most advanced non-optical lithographic technologies are also considering using topics for alignment. In addition, there have been a number of in-situ technologies proposed which use optical measurements to control one aspect or another of the semiconductor process. So optics is definitely not dying out in the semiconductor industry. In this paper a description of recent advances in optical metrology and alignment modeling is presented. The theory of high numerical aperture image simulation for partially coherent illumination is discussed. The implications of telecentric optics on the image simulation is also presented. Reciprocity tests are proposed as an important measure of numerical accuracy. Diffraction efficiencies for chrome gratings on reticles are one good way to test Kirchoff's approximation as compared to rigorous calculations. We find significant differences between the predictions of Kirchoff's approximation and rigorous methods. The methods for simulating brightfield, confocal, and coherence probe microscope imags are outlined, as are methods for describing aberrations such as coma, spherical aberration, and illumination aperture decentering.

Nm-scale spatial resolution x-ray imaging with MLL nanofocusing optics: instrumentational requirements and challenges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nazaretski, E.; Yan, H.; Lauer, K.

2016-08-30

The Hard X-ray Nanoprobe (HXN) beamline at NSLS-II has been designed and constructed to enable imaging experiments with unprecedented spatial resolution and detection sensitivity. The HXN X-ray Microscope is a key instrument for the beamline, providing a suite of experimental capabilities which includes scanning fluorescence, diffraction, differential phase contrast and ptychography utilizing Multilayer Laue Lenses (MLL) and zoneplate (ZP) as nanofocusing optics. In this paper, we present technical requirements for the MLL-based scanning microscope, outline the development concept and present first ~15 x 15 nm 2 spatial resolution x-ray fluorescence images.

Use of scanning near-field optical microscope with an aperture probe for detection of luminescent nanodiamonds

NASA Astrophysics Data System (ADS)

Shershulin, V. A.; Samoylenko, S. R.; Shenderova, O. A.; Konov, V. I.; Vlasov, I. I.

2017-02-01

The suitability of scanning near-field optical microscopy (SNOM) to image photoluminescent diamond nanoparticles with nanoscale resolution is demonstrated. Isolated diamond nanocrystals with an average size of 100 nm, containing negatively charged nitrogen-vacancy (NV-) centers, were chosen as tested material. The NV- luminescence was stimulated by continuous 532 nm laser light. Sizes of analyzed crystallites were monitored by an atomic force microscope. The lateral resolution of the order of 100 nm was reached in SNOM imaging of diamond nanoparticles using 150 nm square aperture of the probe.

The petrographic microscope: Evolution of a mineralogical research instrument

USGS Publications Warehouse

Kile, D.E.

2003-01-01

The petrographic microscope, designed to observe and measure the optical properties of minerals as a means of identifying them, has provided a foundation for mineralogical and petrological research for more than 120 years. Much of what is known today in these fields is attributable to this instrument, the development of which paralleled an evolution of fundamental optical theory and its correlation with mineral structure and composition. This instrument and its related accessories have evolved through a range of models and designs, which are in themselves distinctive for their scientific function and elegant construction, and are today prized by collectors of scientific instruments.

Foucault imaging by using non-dedicated transmission electron microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taniguchi, Yoshifumi; Matsumoto, Hiroaki; Harada, Ken

2012-08-27

An electron optical system for observing Foucault images was constructed using a conventional transmission electron microscope without any special equipment for Lorentz microscopy. The objective lens was switched off and an electron beam was converged by a condenser optical system to the crossover on the selected area aperture plane. The selected area aperture was used as an objective aperture to select the deflected beam for Foucault mode, and the successive image-forming lenses were controlled for observation of the specimen images. The irradiation area on the specimen was controlled by selecting the appropriate diameter of the condenser aperture.

Water without windows: Evaluating the performance of open cell transmission electron microscopy under saturated water vapor conditions, and assessing its potential for microscopy of hydrated biological specimens

PubMed Central

Yamashita, Masao; Cheung, Martin; Kalale, Chola; Adaniya, Hidehito; Kuwahara, Ryusuke; Shintake, Tsumoru

2017-01-01

We have performed open cell transmission electron microscopy experiments through pure water vapor in the saturation pressure regime (>0.6 kPa), in a modern microscope capable of sub-Å resolution. We have systematically studied achievable pressure levels, stability and gas purity, effective thickness of the water vapor column and associated electron scattering processes, and the effect of gas pressure on electron optical resolution and image contrast. For example, for 1.3 kPa pure water vapor and 300kV electrons, we report pressure stability of ± 20 Pa over tens of minutes, effective thickness of 0.57 inelastic mean free paths, lattice resolution of 0.14 nm on a reference Au specimen, and no significant degradation in contrast or stability of a biological specimen (M13 virus, with 6 nm body diameter). We have also done some brief experiments to confirm feasibility of loading specimens into an in situ water vapor ambient without exposure to intermediate desiccating conditions. Finally, we have also checked if water experiments had any discernible impact on the microscope performance, and report pertinent vacuum and electron optical data, for reference purposes. PMID:29099843

Three-dimensional registration of intravascular optical coherence tomography and cryo-image volumes for microscopic-resolution validation.

PubMed

Prabhu, David; Mehanna, Emile; Gargesha, Madhusudhana; Brandt, Eric; Wen, Di; van Ditzhuijzen, Nienke S; Chamie, Daniel; Yamamoto, Hirosada; Fujino, Yusuke; Alian, Ali; Patel, Jaymin; Costa, Marco; Bezerra, Hiram G; Wilson, David L

2016-04-01

Evidence suggests high-resolution, high-contrast, [Formula: see text] intravascular optical coherence tomography (IVOCT) can distinguish plaque types, but further validation is needed, especially for automated plaque characterization. We developed experimental and three-dimensional (3-D) registration methods to provide validation of IVOCT pullback volumes using microscopic, color, and fluorescent cryo-image volumes with optional registered cryo-histology. A specialized registration method matched IVOCT pullback images acquired in the catheter reference frame to a true 3-D cryo-image volume. Briefly, an 11-parameter registration model including a polynomial virtual catheter was initialized within the cryo-image volume, and perpendicular images were extracted, mimicking IVOCT image acquisition. Virtual catheter parameters were optimized to maximize cryo and IVOCT lumen overlap. Multiple assessments suggested that the registration error was better than the [Formula: see text] spacing between IVOCT image frames. Tests on a digital synthetic phantom gave a registration error of only [Formula: see text] (signed distance). Visual assessment of randomly presented nearby frames suggested registration accuracy within 1 IVOCT frame interval ([Formula: see text]). This would eliminate potential misinterpretations confronted by the typical histological approaches to validation, with estimated 1-mm errors. The method can be used to create annotated datasets and automated plaque classification methods and can be extended to other intravascular imaging modalities.

Chromatic confocal microscope using hybrid aspheric diffractive lenses

NASA Astrophysics Data System (ADS)

Rayer, Mathieu; Mansfield, Daniel

2014-05-01

A chromatic confocal microscope is a single point non-contact distance measurement sensor. For three decades the vast majority of the chromatic confocal microscope use refractive-based lenses to code the measurement axis chromatically. However, such an approach is limiting the range of applications. In this paper the performance of refractive, diffractive and Hybrid aspheric diffractive are compared. Hybrid aspheric diffractive lenses combine the low geometric aberration of a diffractive lens with the high optical power of an aspheric lens. Hybrid aspheric diffractive lenses can reduce the number of elements in an imaging system significantly or create large hyper- chromatic lenses for sensing applications. In addition, diffractive lenses can improve the resolution and the dynamic range of a chromatic confocal microscope. However, to be suitable for commercial applications, the diffractive optical power must be significant. Therefore, manufacturing such lenses is a challenge. We show in this paper how a theoretical manufacturing model can demonstrate that the hybrid aspheric diffractive configuration with the best performances is achieved by step diffractive surface. The high optical quality of step diffractive surface is then demonstrated experimentally. Publisher's Note: This paper, originally published on 5/10/14, was replaced with a corrected/revised version on 5/19/14. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.

Wide-band acousto-optic deflectors for large field of view two-photon microscope.

PubMed

Jiang, Runhua; Zhou, Zhenqiao; Lv, Xiaohua; Zeng, Shaoqun

2012-04-01

Acousto-optic deflector (AOD) is an attractive scanner for two-photon microscopy because it can provide fast and versatile laser scanning and does not involve any mechanical movements. However, due to the small scan range of available AOD, the field of view (FOV) of the AOD-based microscope is typically smaller than that of the conventional galvanometer-based microscope. Here, we developed a novel wide-band AOD to enlarge the scan angle. Considering the maximum acceptable acoustic attenuation in the acousto-optic crystal, relatively lower operating frequencies and moderate aperture were adopted. The custom AOD was able to provide 60 MHz 3-dB bandwidth and 80% peak diffraction efficiency at 840 nm wavelength. Based on a pair of such AOD, a large FOV two-photon microscope was built with a FOV up to 418.5 μm (40× objective). The spatiotemporal dispersion was compensated simultaneously with a single custom-made prism. By means of dynamic power modulation, the variation of laser intensity within the FOV was reduced below 5%. The lateral and axial resolution of the system were 0.58-2.12 μm and 2.17-3.07 μm, respectively. Pollen grain images acquired by this system were presented to demonstrate the imaging capability at different positions across the entire FOV. © 2012 American Institute of Physics

Effect of structural transformation of C+-ion implanted PMMA into quasi-continuous carbonaceous layer on its optical and electrical properties

NASA Astrophysics Data System (ADS)

Arif, Shafaq; Rafique, M. Shahid; Saleemi, Farhat; Sagheer, Riffat

2018-02-01

The samples of Polymethylmethacrylate (PMMA) have been implanted with 500 keV C+-ions at different ion fluences ranging from 9.3 × 1013 to 8.4 × 1014 ions/cm2. The structural modifications are examined by Fourier Transform Infrared and Raman spectral studies. For the investigation of optical, electrical and surface morphological properties of implanted samples UV-Visible spectrometer, four probe apparatus and optical microscope have been employed. The FTIR spectra confirmed the cleavage of chemicals bonds as a consequence of polymer chain scission, whereas, Raman studies revealed the transformation of PMMA structure into quasi-continuous amorphous carbon with increasing ion fluences. A continuous reduction has been observed in the optical band gap of PMMA from 3.16 to 1.42 eV. Moreover, the refractive index, extinction coefficient and electrical conductivity of implanted PMMA are found to be an increasing function of the ion fluence. The micrographic images revealed the signatures of ion-induced defects like cracking, dehydrogenation, stress and swelling on the surface of PMMA. These implanted samples have a potential to be used in the field of optical communications and thin plastic flexible electronics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gofron, K. J., E-mail: kgofron@bnl.gov; Cai, Y. Q.; Coburn, D. S.

A novel on-axis X-ray microscope with 3 µm resolution, 3x magnification, and a working distance of 600 mm for in-situ sample alignment and X-ray beam visualization for the Inelastic X-ray Scattering (IXS) beamline at NSLS-II is presented. The microscope uses reflective optics, which minimizes dispersion, and allows imaging from Ultraviolet (UV) to Infrared (IR) with specifically chosen objective components (coatings, etc.). Additionally, a portable high resolution X-ray microscope for KB mirror alignment and X-ray beam characterization was developed.

The microscopes of Antoni van Leeuwenhoek.

PubMed

van Zuylen, J

1981-03-01

The seventeenth-century Dutch microscopist, Antoni van Leeuwenhoek, was the first man to make a protracted study of microscopical objects, and, unlike his contemporary Robert Hooke, he viewed by transmitted light. Leeuwenhoek made over 500 of his own, curious, simple microscopes, but now only nine are known to exist. The exact nature of the lenses Leeuwenhoek made, has for long been a puzzle. The existing microscopes have now been examined in detail, and their optical characteristics measured and tabulated. It is proposed that the lens of highest magnification, x 266, was made using a special blown bubble technique.

Reprint of: Atmospheric scanning electron microscope observes cells and tissues in open medium through silicon nitride film.

PubMed

Nishiyama, Hidetoshi; Suga, Mitsuo; Ogura, Toshihiko; Maruyama, Yuusuke; Koizumi, Mitsuru; Mio, Kazuhiro; Kitamura, Shinichi; Sato, Chikara

2010-11-01

Direct observation of subcellular structures and their characterization is essential for understanding their physiological functions. To observe them in open environment, we have developed an inverted scanning electron microscope with a detachable, open-culture dish, capable of 8 nm resolution, and combined with a fluorescence microscope quasi-simultaneously observing the same area from the top. For scanning electron microscopy from the bottom, a silicon nitride film window in the base of the dish maintains a vacuum between electron gun and open sample dish while allowing electrons to pass through. Electrons are backscattered from the sample and captured by a detector under the dish. Cells cultured on the open dish can be externally manipulated under optical microscopy, fixed, and observed using scanning electron microscopy. Once fine structures have been revealed by scanning electron microscopy, their component proteins may be identified by comparison with separately prepared fluorescence-labeled optical microscopic images of the candidate proteins, with their heavy-metal-labeled or stained ASEM images. Furthermore, cell nuclei in a tissue block stained with platinum-blue were successfully observed without thin-sectioning, which suggests the applicability of this inverted scanning electron microscope to cancer diagnosis. This microscope visualizes mesoscopic-scale structures, and is also applicable to non-bioscience fields including polymer chemistry. Copyright © 2010 Elsevier Inc. All rights reserved.

An automatic system to study sperm motility and energetics

PubMed Central

Nascimento, Jaclyn M.; Chandsawangbhuwana, Charlie; Botvinick, Elliot L.; Berns, Michael W.

2012-01-01

An integrated robotic laser and microscope system has been developed to automatically analyze individual sperm motility and energetics. The custom-designed optical system directs near-infrared laser light into an inverted microscope to create a single-point 3-D gradient laser trap at the focal spot of the microscope objective. A two-level computer structure is described that quantifies the sperm motility (in terms of swimming speed and swimming force) and energetics (measuring mid-piece membrane potential) using real-time tracking (done by the upper-level system) and fluorescent ratio imaging (done by the lower-level system). The communication between these two systems is achieved by a gigabit network. The custom-built image processing algorithm identifies the sperm swimming trajectory in real-time using phase contrast images, and then subsequently traps the sperm by automatically moving the microscope stage to relocate the sperm to the laser trap focal plane. Once the sperm is stably trapped (determined by the algorithm), the algorithm can also gradually reduce the laser power by rotating the polarizer in the laser path to measure the trapping power at which the sperm is capable of escaping the trap. To monitor the membrane potential of the mitochondria located in a sperm’s mid-piece, the sperm is treated with a ratiometrically-encoded fluorescent probe. The proposed algorithm can relocate the sperm to the center of the ratio imaging camera and the average ratio value can be measured in real-time. The three parameters, sperm escape power, sperm swimming speed and ratio values of the mid-piece membrane potential of individual sperm can be compared with respect to time. This two-level automatic system to study individual sperm motility and energetics has not only increased experimental throughput by an order of magnitude but also has allowed us to monitor sperm energetics prior to and after exposure to the laser trap. This system should have application in both the human fertility clinic and in animal husbandry. PMID:18299996

An automatic system to study sperm motility and energetics.

PubMed

Shi, Linda Z; Nascimento, Jaclyn M; Chandsawangbhuwana, Charlie; Botvinick, Elliot L; Berns, Michael W

2008-08-01

An integrated robotic laser and microscope system has been developed to automatically analyze individual sperm motility and energetics. The custom-designed optical system directs near-infrared laser light into an inverted microscope to create a single-point 3-D gradient laser trap at the focal spot of the microscope objective. A two-level computer structure is described that quantifies the sperm motility (in terms of swimming speed and swimming force) and energetics (measuring mid-piece membrane potential) using real-time tracking (done by the upper-level system) and fluorescent ratio imaging (done by the lower-level system). The communication between these two systems is achieved by a gigabit network. The custom-built image processing algorithm identifies the sperm swimming trajectory in real-time using phase contrast images, and then subsequently traps the sperm by automatically moving the microscope stage to relocate the sperm to the laser trap focal plane. Once the sperm is stably trapped (determined by the algorithm), the algorithm can also gradually reduce the laser power by rotating the polarizer in the laser path to measure the trapping power at which the sperm is capable of escaping the trap. To monitor the membrane potential of the mitochondria located in a sperm's mid-piece, the sperm is treated with a ratiometrically-encoded fluorescent probe. The proposed algorithm can relocate the sperm to the center of the ratio imaging camera and the average ratio value can be measured in real-time. The three parameters, sperm escape power, sperm swimming speed and ratio values of the mid-piece membrane potential of individual sperm can be compared with respect to time. This two-level automatic system to study individual sperm motility and energetics has not only increased experimental throughput by an order of magnitude but also has allowed us to monitor sperm energetics prior to and after exposure to the laser trap. This system should have application in both the human fertility clinic and in animal husbandry.

Rapid fabrication of micro-nanometric tapered fiber lens and characterization by a novel scanning optical microscope with submicron resolution.

PubMed

Zheng, Shouguo; Zeng, Xinhua; Luo, Wei; Jradi, Safi; Plain, Jérôme; Li, Miao; Renaud-Goud, Philippe; Deturche, Régis; Wang, Zengfu; Kou, Jieting; Bachelot, Renaud; Royer, Pascal

2013-01-14

In numerous applications of optical scanning microscopy, a reference tapered fiber lens with high symmetry at sub-wavelength scale remains a challenge. Here, we demonstrate the ability to manufacture it with a wide range of geometry control, either for the length from several hundred nanometers to several hundred microns, or for the curvature radius from several tens of nanometers to several microns on the endface of a single mode fiber. On this basis, a scanning optical microscope has been developed, which allows for fast characterization of various sub-wavelength tapered fiber lenses. Focal position and depth of microlenses with different geometries have been determined to be ranged from several hundreds of nanometers to several microns. FDTD calculations are consistent with experimental results.

Microscopic morphology evolution during ion beam smoothing of Zerodur® surfaces.

PubMed

Liao, Wenlin; Dai, Yifan; Xie, Xuhui; Zhou, Lin

2014-01-13

Ion sputtering of Zerodur material often results in the formation of nanoscale microstructures on the surfaces, which seriously influences optical surface quality. In this paper, we describe the microscopic morphology evolution during ion sputtering of Zerodur surfaces through experimental researches and theoretical analysis, which shows that preferential sputtering together with curvature-dependent sputtering overcomes ion-induced smoothing mechanisms leading to granular nanopatterns formation in morphology and the coarsening of the surface. Consequently, we propose a new method for ion beam smoothing (IBS) of Zerodur optics assisted by deterministic ion beam material adding (IBA) technology. With this method, Zerodur optics with surface roughness down to 0.15 nm root mean square (RMS) level is obtained through the experimental investigation, which demonstrates the feasibility of our proposed method.