Science.gov

Sample records for applied diffractive optics

  1. MERTIS: geometrical calibration of thermal infrared optical system by applying diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Bauer, M.; Baumbach, D.; Buder, M.; Börner, A.; Grießbach, D.; Peter, G.; Santier, E.; Säuberlich, T.; Schischmanow, A.; Schrader, S.; Walter, I.

    2015-09-01

    Geometrical sensor calibration is essential for space applications based on high accuracy optical measurements, in this case for the thermal infrared push-broom imaging spectrometer MERTIS. The goal is the determination of the interior sensor orientation. A conventional method is to measure the line of sight for a subset of pixels by single pixel illumination with collimated light. To adjust angles, which define the line of sight of a pixel, a manipulator construction is used. A new method for geometrical sensor calibration is using Diffractive Optical Elements (DOE) in connection with laser beam equipment. Diffractive optical elements (DOE) are optical microstructures, which are used to split an incoming laser beam with a dedicated wavelength into a number of beams with well-known propagation directions. As the virtual sources of the diffracted beams are points at infinity, the resulting image is invariant against translation. This particular characteristic allows a complete geometrical sensor calibration with only one taken image avoiding complex adjustment procedures, resulting in a significant reduction of calibration effort. We present a new method for geometrical calibration of a thermal infrared optical system, including an thermal infrared test optics and the MERTIS spectrometer bolometer detector. The fundamentals of this new approach for geometrical infrared optical systems calibration by applying diffractive optical elements and the test equipment are shown.

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

    PubMed

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

    2016-03-01

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

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

    PubMed Central

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

    2016-01-01

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

  4. Study of optical Laue diffraction

    SciTech Connect

    Chakravarthy, Giridhar E-mail: aloksharan@email.com; Allam, Srinivasa Rao E-mail: aloksharan@email.com; Satyanarayana, S. V. M. E-mail: aloksharan@email.com; Sharan, Alok E-mail: aloksharan@email.com

    2014-10-15

    We present the study of the optical diffraction pattern of one and two-dimensional gratings with defects, designed using desktop pc and printed on OHP sheet using laser printer. Gratings so prepared, using novel low cost technique provides good visual aid in teaching. Diffraction pattern of the monochromatic light (632.8nm) from the grating so designed is similar to that of x-ray diffraction pattern of crystal lattice with point defects in one and two-dimensions. Here both optical and x-ray diffractions are Fraunhofer. The information about the crystalline lattice structure and the defect size can be known.

  5. Digital diffractive optics: Have diffractive optics entered mainstream industry yet?

    NASA Astrophysics Data System (ADS)

    Kress, Bernard; Hejmadi, Vic

    2010-05-01

    When a new technology is integrated into industry commodity products and consumer electronic devices, and sold worldwide in retail stores, it is usually understood that this technology has then entered the realm of mainstream technology and therefore mainstream industry. Such a leap however does not come cheap, as it has a double edge sword effect: first it becomes democratized and thus massively developed by numerous companies for various applications, but also it becomes a commodity, and thus gets under tremendous pressure to cut down its production and integration costs while not sacrificing to performance. We will show, based on numerous examples extracted from recent industry history, that the field of Diffractive Optics is about to undergo such a major transformation. Such a move has many impacts on all facets of digital diffractive optics technology, from the optical design houses to the micro-optics foundries (for both mastering and volume replication), to the final product integrators or contract manufacturers. The main causes of such a transformation are, as they have been for many other technologies in industry, successive technological bubbles which have carried and lifted up diffractive optics technology within the last decades. These various technological bubbles have been triggered either by real industry needs or by virtual investment hype. Both of these causes will be discussed in the paper. The adjective ""digital"" in "digital diffractive optics" does not refer only, as it is done in digital electronics, to the digital functionality of the element (digital signal processing), but rather to the digital way they are designed (by a digital computer) and fabricated (as wafer level optics using digital masking techniques). However, we can still trace a very strong similarity between the emergence of micro-electronics from analog electronics half a century ago, and the emergence of digital optics from conventional optics today.

  6. Fiber optic diffraction grating maker

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1991-01-01

    A compact and portable diffraction grating maker comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate.

  7. Fiber optic diffraction grating maker

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1991-05-21

    A compact and portable diffraction grating maker is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate. 4 figures.

  8. Issues in Optical Diffraction Theory

    PubMed Central

    Mielenz, Klaus D.

    2009-01-01

    This paper focuses on unresolved or poorly documented issues pertaining to Fresnel’s scalar diffraction theory and its modifications. In Sec. 2 it is pointed out that all thermal sources used in practice are finite in size and errors can result from insufficient coherence of the optical field. A quarter-wave criterion is applied to show how such errors can be avoided by placing the source at a large distance from the aperture plane, and it is found that in many cases it may be necessary to use collimated light as on the source side of a Fraunhofer experiment. If these precautions are not taken the theory of partial coherence may have to be used for the computations. In Sec. 3 it is recalled that for near-zone computations the Kirchhoff or Rayleigh-Sommerfeld integrals are applicable, but fail to correctly describe the energy flux across the aperture plane because they are not continuously differentiable with respect to the assumed geometrical field on the source side. This is remedied by formulating an improved theory in which the field on either side of a semi-reflecting screen is expressed as the superposition of mutually incoherent components which propagate in the opposite directions of the incident and reflected light. These components are defined as linear combinations of the Rayleigh-Sommerfeld integrals, so that they are rigorous solutions of the wave equation as well as continuously differentiable in the aperture plane. Algorithms for using the new theory for computing the diffraction patterns of circular apertures and slits at arbitrary distances z from either side of the aperture (down to z = ± 0.0003 λ) are presented, and numerical examples of the results are given. These results show that the incident geometrical field is modulated by diffraction before it reaches the aperture plane while the reflected field is spilled into the dark space. At distances from the aperture which are large compared to the wavelength λ these field expressions are

  9. Spectral diffraction efficiency characterization of broadband diffractive optical elements.

    SciTech Connect

    Choi, Junoh; Cruz-Cabrera, Alvaro Augusto; Tanbakuchi, Anthony

    2013-03-01

    Diffractive optical elements, with their thin profile and unique dispersion properties, have been studied and utilized in a number of optical systems, often yielding smaller and lighter systems. Despite the interest in and study of diffractive elements, the application has been limited to narrow spectral bands. This is due to the etch depths, which are optimized for optical path differences of only a single wavelength, consequently leading to rapid decline in efficiency as the working wavelength shifts away from the design wavelength. Various broadband diffractive design methodologies have recently been developed that improve spectral diffraction efficiency and expand the working bandwidth of diffractive elements. We have developed diffraction efficiency models and utilized the models to design, fabricate, and test two such extended bandwidth diffractive designs.

  10. Microbeam High Angular Resolution Diffraction Applied to Optoelectronic Devices

    SciTech Connect

    Kazimirov, A.; Bilderback, D. H.; Sirenko, A. A.; Cai, Z.-H.; Lai, B.

    2007-01-19

    Collimating perfect crystal optics in a combination with the X-ray focusing optics has been applied to perform high angular resolution microbeam diffraction and scattering experiments on micron-size optoelectronic devices produced by modern semiconductor technology. At CHESS, we used capillary optics and perfect Si/Ge crystal(s) arrangement to perform X-ray standing waves, high angular-resolution diffraction and high resolution reciprocal space mapping analysis. At the APS, 2ID-D microscope beamline, we employed a phase zone plate producing a beam with the size of 240 nm in the horizontal plane and 350 nm in the vertical (diffraction) plane and a perfect Si (004) analyzer crystal to perform diffraction analysis of selectively grown InGaAsP and InGaAlAs-based waveguides with arc sec angular resolution.

  11. Diffractive optical element for optical data storage

    NASA Astrophysics Data System (ADS)

    Yoshida, S.; Unno, N.; Akamatsu, H.; Yamada, K.; Taniguchi, J.; Yamamoto, M.

    2013-05-01

    The diffractive optical element (DOE) has the transformation function of wavefront, and its applications are forming or homogenization of beam, and aberration correction, and so on. In this study, we evaluate possibility as storage application of the DOE. The optical data storage using the DOE is thought of as a kind of holographic data storage (HDS). In the HDS, digital data is recorded and read out as modulated 2-dimensional page data, instead of bit-by-bit recording in conventional optical storages. Therefore, HDS actualize high data transfer rate. We design and optimize phase distribution of the DOE using the iterative method with regularization. In the optimization process, we use iterative Fourier transform algorithm (IFTA) that is known as Gerchberg-Saxton (GS) algorithm. At this time, the regularization method is adopted to suppress minute oscillation of the diffraction pattern. Designed and optimized DOE is fabricated by ultraviolet (UV) nanoimprinting technology. High productivity can be expected by adopting nanoimprinting technology. DOEs are duplicated on the silicon (Si) substrate as reflection-type elements. Fabricated DOE is evaluated in the experiment. We verify that DOE for optical data storage can be actualized through our approach.

  12. Diffraction optics for terahertz waves

    NASA Astrophysics Data System (ADS)

    Wiltse, James C.

    2004-09-01

    Conventional lenses are important components for many terahertz applications, but ordinary lenses are very difficult to fabricate for short-focal lengths. Multi-level phase-corrected zoned lens antennas have been investigated with particular application at terahertz wavelengths. These zoned lenses (or diffractive optics) give better performance than ordinary lenses, and because of their planar construction are easier and cheaper to fabricate. The depths of cut needed for a grooved zone plate are quite small, even when materials with low dielectric constants are used. Zoned lenses have been built and tested at various frequencies from 100 GHz to 1.5 THz, with phase correction levels of half-wave, quarter-wave, or eighth-wavelength. The inherent losses in transparent materials increase monotonically over this frequency range. Typical low-loss materials include polystyrene, polyethylene, Teflon, polycarbonate, polystyrene foam, foamed polyethylene, low density polytetrafluoroethylene (PTFE), TPX, quartz, sapphire, and silicon. Low dielectric-constant materials are normally preferred to reduce reflection and attenuation losses. Techniques for cutting or milling the materials to small dimensions are important, because at 1.0 THz an eighth-wavelength correction for silicon is only 15 μm. Another characteristic of zoned diffraction optics is their frequency behavior. Previous investigations have considered their bandwidth dependence and quasi-periodic extended frequency response for a specified focal length. As frequency changes, the focal point moves along the axis of the zoned lens. An analysis is given to explain this effect.

  13. Sub-wavelength diffractive optics

    SciTech Connect

    Warren, M.E.; Wendt, J.R.; Vawter, G.A.

    1998-03-01

    This report represents the completion of a three-year Laboratory-Directed Research and Development (LDRD) program to investigate sub-wavelength surface relief structures fabricated by direct-write e-beam technology as unique and very high-efficiency optical elements. A semiconductor layer with sub-wavelength sized etched openings or features can be considered as a layer with an effective index of refraction determined by the fraction of the surface filled with semiconductor relative to the fraction filled with air or other material. Such as a layer can be used to implement planar gradient-index lenses on a surface. Additionally, the nanometer-scale surface structures have diffractive properties that allow the direct manipulation of polarization and altering of the reflective properties of surfaces. With this technology a single direct-write mask and etch can be used to integrate a wide variety of optical functions into a device surface with high efficiencies; allowing for example, direct integration of polarizing optics into the surface with high efficiencies; allowing for example, direct integration of polarizing optics into the surfaces of devices, forming anti-reflection surfaces or fabricating high-efficiency, high-numerical aperture lenses, including integration inside vertical semiconductor laser cavities.

  14. Diffractive optical element in materials testing

    NASA Astrophysics Data System (ADS)

    Silvennoinen, Raimo V. J.; Peiponen, Kai-Erik

    1998-09-01

    The object of this paper is to present a sensor based on diffractive optics that can be applied for the materials testing. The present sensor, which is based on the use of a computer-generated hologram (CGH) exploits the holographic imagery. The CGH-sensor was introduced for inspection of surface roughness and flatness of metal surfaces. The results drawn out by the present sensor are observed to be in accordance with the experimental data. Together with the double exposure holographic interferometry (DEHI) and digital electronic speckle pattern interferometry (DSPI) in elasticity inspection, the sensor was applied for the investigations of surface quality of opaque fragile materials, which are pharmaceutical compacts. The optical surface quality was observed to be related to the porosity of the pharmaceutical tablets. The CGH-sensor was also applied for investigations of optical quality of thin films as PLZT ceramics and coating of pharmaceutical compacts. The surfaces of PLZT samples showed fluctuations in optical curvature, and wedgeness for all the cases studied. For pharmaceutical compacts, the optical signals were observed to depend to a great extent on the optical constants of the coatings and the substrates, and in addition to the surface porosity under the coating.

  15. Diffraction gratings for optical sensing

    NASA Astrophysics Data System (ADS)

    Lu, Patrick P.

    The following document summarizes a journey through the world of diffraction gratings, covering topics such as their history, fabrication, metrology, and uses in some of the most precise scientific experiments ever proposed. Though diffraction gratings have long been used for spectroscopy and pulse compression, it was not until recently that researchers have explored their ability to split and recombine single-frequency CW laser sources for high-precision interferometry. Gravitational-wave detection, one of the most challenging sensing applications to date, is being investigated by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Laser Interferometer Space Antenna (LISA) projects. Future generations of LIGO and LISA detectors may incorporate gratings as key optical components. This thesis describes the ways gratings can improve interferometer performance by simplifying thermal management and discusses the essential challenges that must be overcome before they can be adopted. The use of gratings requires new interferometer geometries. We show cases where these can be implemented simply and compactly. Gravitational-wave interferometry imposes many requirements on grating components. Using improved metrology methods, we demonstrate that large dielectric gratings with uniformly high efficiency can be fabricated and validated. In particular, we measure the diffraction efficiency of two 20-cm-scale gratings over their entire apertures. The values taken from across their surfaces collectively had means and standard deviations of mu = 99.293% and sigma = 0.164%, and mu =99.084% and sigma =0.079%. We also present simplified models of thermal distortions in gratings, and show them to be in good agreement with measurements conducted by a wavefront sensor. Special focus is given to experimental demonstrations that have achieved highly precise measurements of translational and rotational motion, also known as displacement and angular sensing. For the former

  16. Diffraction-based optical correlator

    NASA Technical Reports Server (NTRS)

    Spremo, Stevan M. (Inventor); Fuhr, Peter L. (Inventor); Schipper, John F. (Inventor)

    2005-01-01

    Method and system for wavelength-based processing of a light beam. A light beam, produced at a chemical or physical reaction site and having at least first and second wavelengths, ?1 and ?2, is received and diffracted at a first diffraction grating to provide first and second diffracted beams, which are received and analyzed in terms of wavelength and/or time at two spaced apart light detectors. In a second embodiment, light from first and second sources is diffracted and compared in terms of wavelength and/or time to determine if the two beams arise from the same source. In a third embodiment, a light beam is split and diffracted and passed through first and second environments to study differential effects. In a fourth embodiment, diffracted light beam components, having first and second wavelengths, are received sequentially at a reaction site to determine whether a specified reaction is promoted, based on order of receipt of the beams. In a fifth embodiment, a cylindrically shaped diffraction grating (uniform or chirped) is rotated and translated to provide a sequence of diffracted beams with different wavelengths. In a sixth embodiment, incident light, representing one or more symbols, is successively diffracted from first and second diffraction gratings and is received at different light detectors, depending upon the wavelengths present in the incident light.

  17. High diffraction efficiency of three-layer diffractive optics designed for wide temperature range and large incident angle.

    PubMed

    Mao, Shan; Cui, Qingfeng; Piao, Mingxu; Zhao, Lidong

    2016-05-01

    A mathematical model of diffraction efficiency and polychromatic integral diffraction efficiency affected by environment temperature change and incident angle for three-layer diffractive optics with different dispersion materials is put forward, and its effects are analyzed. Taking optical materials N-FK5 and N-SF1 as the substrates of multilayer diffractive optics, the effect on diffraction efficiency and polychromatic integral diffraction efficiency with intermediate materials POLYCARB is analyzed with environment temperature change as well as incident angle. Therefore, three-layer diffractive optics can be applied in more wide environmental temperature ranges and larger incident angles for refractive-diffractive hybrid optical systems, which can obtain better image quality. Analysis results can be used to guide the hybrid imaging optical system design for optical engineers. PMID:27140370

  18. Diffraction efficiency analysis for multi-level diffractive optical elements

    SciTech Connect

    Erteza, I.A.

    1995-11-01

    Passive optical components can be broken down into two main groups: Refractive elements and diffractive elements. With recent advances in manufacturing technologies, diffractive optical elements are becoming increasingly more prevalent in optical systems. It is therefore important to be able to understand and model the behavior of these elements. In this report, we present a thorough analysis of a completely general diffractive optical element (DOE). The main goal of the analysis is to understand the diffraction efficiency and power distribution of the various modes affected by the DOE. This is critical to understanding cross talk and power issues when these elements are used in actual systems. As mentioned, the model is based on a completely general scenario for a DOE. This allows the user to specify the details to model a wide variety of diffractive elements. The analysis is implemented straightforwardly in Mathematica. This report includes the development of the analysis, the Mathematica implementation of the model and several examples using the Mathematical analysis tool. It is intended that this tool be a building block for more specialized analyses.

  19. Perturbation approach applied to modal diffraction methods.

    PubMed

    Bischoff, Joerg; Hehl, Karl

    2011-05-01

    Eigenvalue computation is an important part of many modal diffraction methods, including the rigorous coupled wave approach (RCWA) and the Chandezon method. This procedure is known to be computationally intensive, accounting for a large proportion of the overall run time. However, in many cases, eigenvalue information is already available from previous calculations. Some of the examples include adjacent slices in the RCWA, spectral- or angle-resolved scans in optical scatterometry and parameter derivatives in optimization. In this paper, we present a new technique that provides accurate and highly reliable solutions with significant improvements in computational time. The proposed method takes advantage of known eigensolution information and is based on perturbation method. PMID:21532698

  20. Diffractive optics for compact flat panel displays. Final report

    SciTech Connect

    Sweeney, D.; DeLong, K.

    1997-04-29

    Three years ago LLNL developed a practical method to dramatically reduce the chromatic aberration in single element diffractive imaging lenses. High efficiency, achromatic imaging lenses have been fabricated for human vision correction. This LDRD supported research in applying our new methods to develop a unique, diffraction-based optical interface with solid state, microelectronic imaging devices. Advances in microelectronics have led to smaller, more efficient components for optical systems. There have, however, been no equivalent advances in the imaging optics associated with these devices. The goal of this project was to replace the bulky, refractive optics in typical head-mounted displays with micro-thin diffractive optics to directly image flat-panel displays into the eye. To visualize the system think of the lenses of someone`s eyeglasses becoming flat-panel displays. To realize this embodiment, we needed to solve the problems of large chromatic aberrations and low efficiency that are associated with diffraction. We have developed a graceful tradeoff between chromatic aberrations and the diffractive optic thickness. It turns out that by doubling the thickness of a micro-thin diffractive lens we obtain nearly a two-times improvement in chromatic performance. Since the human eye will tolerate one diopter of chromatic aberration, we are able to achieve an achromatic image with a diffractive lens that is only 20 microns thick, versus 3 mm thickness for the comparable refractive lens. Molds for the diffractive lenses are diamond turned with sub-micron accuracy; the final lenses are cast from these molds using various polymers. We thus retain both the micro- thin nature of the diffractive optics and the achromatic image quality of refractive optics. During the first year of funding we successfully extended our earlier technology from 1 cm diameter optics required for vision applications up to the 5 cm diameter optics required for this application. 3 refs., 6 figs.

  1. Scalar limitations of diffractive optical elements

    NASA Technical Reports Server (NTRS)

    Johnson, Eric G.; Hochmuth, Diane; Moharam, M. G.; Pommet, Drew

    1993-01-01

    In this paper, scalar limitations of diffractive optic components are investigated using coupled wave analyses. Results are presented for linear phase gratings and fanout devices. In addition, a parametric curve is given which correlates feature size with scalar performance.

  2. Bayesian inversion for optical diffraction tomography

    NASA Astrophysics Data System (ADS)

    Ayasso, H.; Duchêne, B.; Mohammad-Djafari, A.

    2010-05-01

    In this paper, optical diffraction tomography is considered as a non-linear inverse scattering problem and tackled within the Bayesian estimation framework. The object under test is a man-made object known to be composed of compact regions made of a finite number of different homogeneous materials. This a priori knowledge is appropriately translated by a Gauss-Markov-Potts prior. Hence, a Gauss-Markov random field is used to model the contrast distribution whereas a hidden Potts-Markov field accounts for the compactness of the regions. First, we express the a posteriori distributions of all the unknowns and then a Gibbs sampling algorithm is used to generate samples and estimate the posterior mean of the unknowns. Some preliminary results, obtained by applying the inversion algorithm to laboratory controlled data, are presented.

  3. Spatiotemporal optical pulse transformation by a resonant diffraction grating

    SciTech Connect

    Golovastikov, N. V.; Bykov, D. A. Doskolovich, L. L. Soifer, V. A.

    2015-11-15

    The diffraction of a spatiotemporal optical pulse by a resonant diffraction grating is considered. The pulse diffraction is described in terms of the signal (the spatiotemporal incident pulse envelope) passage through a linear system. An analytic approximation in the form of a rational function of two variables corresponding to the angular and spatial frequencies has been obtained for the transfer function of the system. A hyperbolic partial differential equation describing the general form of the incident pulse envelope transformation upon diffraction by a resonant diffraction grating has been derived from the transfer function. A solution of this equation has been obtained for the case of normal incidence of a pulse with a central frequency lying near the guided-mode resonance of a diffraction structure. The presented results of numerical simulations of pulse diffraction by a resonant grating show profound changes in the pulse envelope shape that closely correspond to the proposed theoretical description. The results of the paper can be applied in creating new devices for optical pulse shape transformation, in optical information processing problems, and analog optical computations.

  4. X-Ray Diffractive Optics

    NASA Technical Reports Server (NTRS)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

    X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

  5. Optimization Algorithm for Designing Diffractive Optical Elements

    NASA Astrophysics Data System (ADS)

    Agudelo, Viviana A.; Orozco, Ricardo Amézquita

    2008-04-01

    Diffractive Optical Elements (DOEs) are commonly used in many applications such as laser beam shaping, recording of micro reliefs, wave front analysis, metrology and many others where they can replace single or multiple conventional optical elements (diffractive or refractive). One of the most versatile way to produce them, is to use computer assisted techniques for their design and optimization, as well as optical or electron beam micro-lithography techniques for the final fabrication. The fundamental figures of merit involved in the optimization of such devices are both the diffraction efficiency and the signal to noise ratio evaluated in the reconstructed wave front at the image plane. A design and optimization algorithm based on the error—reduction method (Gerchberg and Saxton) is proposed to obtain binary discrete phase-only Fresnel DOEs that will be used to produce specific intensity patterns. Some experimental results were obtained using a spatial light modulator acting as a binary programmable diffractive phase element. Although the DOEs optimized here are discrete in phase, they present an acceptable signal noise relation and diffraction efficiency.

  6. Optical microscopy beyond the diffraction limit

    PubMed Central

    Smolyaninov, Igor I.

    2008-01-01

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

  7. Overview Of Diffractive Optics At Honeywell

    NASA Astrophysics Data System (ADS)

    Cox, J. Allen

    1988-05-01

    Interest in holographic, or diffractive, optics has been rekindled in the last few years with demonstrated advances in three areas: computer-aided design (CAD) tools, VLSI lithographic and dry etching processes, and mathematical modeling of diffractive elements.1 The availability of CAD tools and electron-beam lithography led first to the emergence of computer-generated holography (CGH). CGH work at Honeywell was started and brought to maturity by Arnold2 in 1980-1983. However, because of the inherently low diffraction efficiency (-10%), lithographic CGHs have found a place in only a relatively few practical applications, such as testing diamond turned aspherics, and thus CGHs have not been widely accepted within industry. The first step in changing this situation came in the 1970s with numerical approaches to rigorously solve the vector field equations for diffraction from blazed gratings.3 The extensive numerical results from these models not only showed that high diffraction efficiencies are possible with etched surface profiles, but also indicated the sensitivity to various profile configurations and design parameters. Veldkamp et al.1,4'-'61 at MIT Lincoln Laboratories have taken the final step necessary to establish the practical feasibility of diffractive optics by using reactive ion etching techniques to produce the surface profiles prescribed by the numerical models and delineated by CGH lithographic masks. With this combined approach, they have demonstrated the feasibility of high-efficiency diffractive elements for a variety of diverse applications, such as the CO2 laser radar telescope,4 coherent beam addition of laser diode arrays,5 and on-axis, broadband, aspheric lens elements for infrared imagers.6 These elements are fabricated using well-established VLSI lithographic and dry etching techniques. Moreover, the ability to replicate each diffractive element provides the potential for high-volume, low-cost producibility. With this precedent, Honeywell

  8. Integrated Diffractive Optics for Surface Ion Traps

    NASA Astrophysics Data System (ADS)

    Streed, Erik; Ghadimi, Moji; Blums, Valdis; Norton, Benjamin; Connor, Paul; Amini, Jason; Volin, Curtis; Lobino, Mirko; Kielpinski, David

    2016-05-01

    Photonic interconnects are a bottleneck to achieving large-scale trapped ion quantum computing. We have modified a Georgia Tech Research Institute microwave chip trap by using e-beam lithography to write reflective diffractive collimating optics (80 μm x 127 μm, f=58.6 μm, λ=369.5nm) on the center electrode. The optics have an NA of 0.55 x 0.73, capturing 13.2% of the solid angle. To evaluate the optics 174Yb+ was loaded by isotope selective photo-ionization from a thermal oven and then shuttled to imaging sites. Near diffraction limited sub-wavelength ion images were obtained with an observed spot sized FWHM of 338 nm x 268 nm vs. a diffraction limit of 336 nm x 257 nm. The total photon collection efficiency was measured to be 5.2+/-1.2%. Coupling into a single mode fiber of up to 2.0+/-0.6% was observed, limited by mismatch in the coupling optics. Image mode quality indicates coupling up to 4% may be possible. Funding from Australian Research Council and IARPA.

  9. Optical diffraction by inhomogeneous volume objects

    NASA Astrophysics Data System (ADS)

    Forte, Gustavo; Lencina, Alberto; Tebaldi, Myrian; Bolognini, Nestor

    2008-08-01

    Electromagnetic waves propagation research in volume media increases considerably in the last years. The study evolved from thick hologram gratings, Bragg and Raman-Nath diffraction regimes up to current research in photonics materials. Usually differential methods are employed to account for the light transmitted for volume media. In our proposal, we develop a simple and versatile integral method to calculate the diffracted field provided the media refractive index has low variations in a wavelength scale. In fact, starting from first principles, we obtain a modified version of the Fresnel propagator of the scalar diffraction theory. Our method is valid for some kind of magnetic, dielectric and absorbent inhomogeneous media. In particular, for TE (TM) fields, we can study media where the permittivity (permeability) gradient is perpendicular to the electric (magnetic) field and its permeability (permittivity) is constant. To validate the approach, we applied it to (in) homogeneous media having well known diffraction properties.

  10. Transmissive Diffractive Optical Element Solar Concentrators

    NASA Technical Reports Server (NTRS)

    Baron, Richard; Moynihan, Philip; Price, Douglas

    2008-01-01

    Solar-thermal-radiation concentrators in the form of transmissive diffractive optical elements (DOEs) have been proposed as alternatives to mirror-type solar concentrators now in use. In comparison with functionally equivalent mirror-type solar concentrators, the transmissive, diffractive solar concentrators would weigh and cost less, and would be subject to relaxed mechanical tolerances. A DOE concentrator would be made from a thin, flat disk or membrane of a transmissive material having a suitable index of refraction. By virtue of its thinness, the DOE concentrator would have an areal mass density significantly less than that of a functionally equivalent conventional mirror. The DOE concentrator would have a relatively wide aperture--characterized by a focal-length/aperture-diameter ratio ('f number') on the order of 1. A kinoform (a surface-relief phase hologram) of high diffractive order would be microfabricated onto one face of the disk. The kinoform (see figure) would be designed to both diffract and refract incident solar radiation onto a desired focal region, without concern for forming an image of the Sun. The high diffractive order of this kinoform (in contradistinction to the low diffractive orders of some other kinoforms) would be necessary to obtain the desired f number of 1, which, in turn, would be necessary for obtaining a desired concentration ratio of 2,500 or greater. The design process of optimizing the concentration ratio of a proposed DOE solar concentrator includes computing convolutions of the optical bandwidth of the Sun with the optical transmission of the diffractive medium. Because, as in the cases of other non-imaging, light-concentrating optics, image quality is not a design requirement, the process also includes trading image quality against concentration ratio. A baseline design for one example calls for an aperture diameter of 1 m. This baseline design would be scalable to a diameter as large as 10 m, or to a smaller diameter for a

  11. Diffraction smoothing aperture for an optical beam

    DOEpatents

    Judd, O'Dean P.; Suydam, Bergen R.

    1976-01-01

    The disclosure is directed to an aperture for an optical beam having an irregular periphery or having perturbations imposed upon the periphery to decrease the diffraction effect caused by the beam passing through the aperture. Such apertures are particularly useful with high power solid state laser systems in that they minimize the problem of self-focusing which frequently destroys expensive components in such systems.

  12. Surface diffusion studies by optical diffraction techniques

    SciTech Connect

    Xiao, X.D.

    1992-11-01

    The newly developed optical techniques have been combined with either second harmonic (SH) diffraction or linear diffraction off a monolayer adsorbate grating for surface diffusion measurement. Anisotropy of surface diffusion of CO on Ni(l10) was used as a demonstration for the second harmonic dim reaction method. The linear diffraction method, which possesses a much higher sensitivity than the SH diffraction method, was employed to study the effect of adsorbate-adsorbate interaction on CO diffusion on Ni(l10) surface. Results showed that only the short range direct CO-CO orbital overlapping interaction influences CO diffusion but not the long range dipole-dipole and CO-NI-CO interactions. Effects of impurities and defects on surface diffusion were further explored by using linear diffraction method on CO/Ni(110) system. It was found that a few percent S impurity can alter the CO diffusion barrier height to a much higher value through changing the Ni(110) surface. The point defects of Ni(l10) surface seem to speed up CO diffusion significantly. A mechanism with long jumps over multiple lattice distance initiated by CO filled vacancy is proposed to explain the observed defect effect.

  13. Diffractive interference optical analyzer (DiOPTER)

    NASA Astrophysics Data System (ADS)

    Sasikumar, Harish; Prasad, Vishnu; Pal, Parama; Varma, Manoj M.

    2016-03-01

    This report demonstrates a method for high-resolution refractometric measurements using, what we have termed as, a Diffractive Interference Optical Analyzer (DiOpter). The setup consists of a laser, polarizer, a transparent diffraction grating and Si-photodetectors. The sensor is based on the differential response of diffracted orders to bulk refractive index changes. In these setups, the differential read-out of the diffracted orders suppresses signal drifts and enables time-resolved determination of refractive index changes in the sample cell. A remarkable feature of this device is that under appropriate conditions, the measurement sensitivity of the sensor can be enhanced by more than two orders of magnitude due to interference between multiply reflected diffracted orders. A noise-equivalent limit of detection (LoD) of 6x10-7 RIU was achieved in glass. This work focuses on devices with integrated sample well, made on low-cost PDMS. As the detection methodology is experimentally straightforward, it can be used across a wide array of applications, ranging from detecting changes in surface adsorbates via binding reactions to estimating refractive index (and hence concentration) variations in bulk samples. An exciting prospect of this technique is the potential integration of this device to smartphones using a simple interface based on transmission mode configuration. In a transmission configuration, we were able to achieve an LoD of 4x10-4 RIU which is sufficient to explore several applications in food quality testing and related fields. We are envisioning the future of this platform as a personal handheld optical analyzer for applications ranging from environmental sensing to healthcare and quality testing of food products.

  14. Two diffusion photopolymer for sharp diffractive optical elements recording.

    PubMed

    Gallego, S; Fernández, R; Márquez, A; Ortuño, M; Neipp, C; Gleeson, M R; Sheridan, J T; Beléndez, A

    2015-07-15

    Photopolymers as recording media are widely used in optical applications. In such materials, changes in the phase of the transmittance function are generated during exposure due to refractive index and thickness modulations. These changes arise primarily as a consequence of photopolymerization and mass transport processes. Characterizing polymers' performance, for example, quantifying the value of monomer diffusion, is therefore very important. Applying index matching, the volume and surface optical effect are separated in an acrylamide/polyvinylalcohol (AA/PVA) material. Using a simplified model that includes the effects of the holes produced during polymerization, both hole and monomer diffusion are analyzed. The analysis presented indicates higher material sensitivity than previously estimated. The results also indicate the possibility of recording sharper diffractive optical elements profiles, like blazed gratings, having diffraction efficiencies higher than 80%. PMID:26176434

  15. Printing colour at the optical diffraction limit.

    PubMed

    Kumar, Karthik; Duan, Huigao; Hegde, Ravi S; Koh, Samuel C W; Wei, Jennifer N; Yang, Joel K W

    2012-09-01

    The highest possible resolution for printed colour images is determined by the diffraction limit of visible light. To achieve this limit, individual colour elements (or pixels) with a pitch of 250 nm are required, translating into printed images at a resolution of ∼100,000 dots per inch (d.p.i.). However, methods for dispensing multiple colourants or fabricating structural colour through plasmonic structures have insufficient resolution and limited scalability. Here, we present a non-colourant method that achieves bright-field colour prints with resolutions up to the optical diffraction limit. Colour information is encoded in the dimensional parameters of metal nanostructures, so that tuning their plasmon resonance determines the colours of the individual pixels. Our colour-mapping strategy produces images with both sharp colour changes and fine tonal variations, is amenable to large-volume colour printing via nanoimprint lithography, and could be useful in making microimages for security, steganography, nanoscale optical filters and high-density spectrally encoded optical data storage. PMID:22886173

  16. Advanced X-ray diffractive optics

    NASA Astrophysics Data System (ADS)

    Vila-Comamala, J.; Jefimovs, K.; Pilvi, T.; Ritala, M.; Sarkar, S. S.; Solak, H. H.; Guzenko, V. A.; Stampanoni, M.; Marone, F.; Raabe, J.; Tzvetkov, G.; Fink, R. H.; Grolimund, D.; Borca, C. N.; Kaulich, B.; David, C.

    2009-09-01

    X-ray microscopy greatly benefits from the advances in x-ray optics. At the Paul Scherrer Institut, developments in x-ray diffractive optics include the manufacture and optimization of Fresnel zone plates (FZPs) and diffractive optical elements for both soft and hard x-ray regimes. In particular, we demonstrate here a novel method for the production of ultra-high resolution FZPs. This technique is based on the deposition of a zone plate material (iridium) onto the sidewalls of a prepatterned template structure (silicon) by atomic layer deposition. This approach overcomes the limitations due to electron-beam writing of dense patterns in FZP fabrication and provides a clear route to push the resolution into sub-10 nm regime. A FZP fabricated by this method was used to resolve test structures with 12 nm lines and spaces at the scanning transmission x-ray microscope of the PolLux beamline of the Swiss Light Source at 1.2 keV photon energy.

  17. Using multiple diffractive optical elements in infrared lens design

    NASA Astrophysics Data System (ADS)

    Sinclair, R. Lawrence; High, Martin; Strnad, Vladimir

    1999-07-01

    Many IR lenses include Diffractive Optical Elements (DOEs) which have been incorporated to reduce the lens complexity and/or the tolerance sensitivity. In many cases the diffractive surface includes an asphere to achieve further aberration correction. For complex lens systems such as IR multi-FOV and IR zoom lenses there is a strong motivation to use multiple diffractive optical elements. This paper reviews the performance impact and productivity advantages of using multiple diffractive optical elements in an IR lens.

  18. Athermalization and thermal characteristics of multilayer diffractive optical elements.

    PubMed

    Wang, Ju; Xue, Changxi

    2015-11-20

    A mathematical model to analyze the thermal characteristics of the multilayer diffractive optical elements (MLDOEs) is presented with consideration of the thermal characteristics for the refractive optical elements and single-layer diffractive optical elements. The analysis process of athermalization for MLDOEs by using the opto-thermal expansion coefficient of optical materials is given. Meanwhile, the microstructure heights of surface relief MLDOEs, the optical path difference, and the polychromatic integral diffraction efficiency with the ambient temperature changed are analyzed. The analysis results can be used to guide an athermalization design for the hybrid refractive-diffractive optical systems with MLDOEs. PMID:26836521

  19. MERTIS: using diffractive optical elements for geometrical calibration

    NASA Astrophysics Data System (ADS)

    Bauer, M.; Griessbach, D.; Säuberlich, T.; Scheele, M.; Schischmanow, A.

    2010-09-01

    Geometrical sensor calibration is essential for space applications based on high accuracy optical measurements, in this case for MERTIS. The goal is the determination of interiour sensor parameters. A conventional method is to measure the line of sight for a subset of pixels by single pixel illumination with collimated light. To adjust angles which define the line of sight of a pixel a manipulator construction is used. A new method for geometrical sensor calibration is presented using Diffractive Optical Elements (DOE) in connection with laser beam equipment. This method is especially used for 2D-sensor array systems but can also be applied to the thermal infrared push-broom imaging spectrometer MERTIS. Diffractive optical elements (DOE) are optical microstructures which are used to split an incoming laser beam with a dedicated wavelength into a number of beams with well-known propagation directions. As the virtual sources of the diffracted beams are points at infinity, the object to be imaged is similar to the starry sky which gives an image invariant against translation. This particular feature allows a complete geometrical sensor calibration with one image avoiding complex adjustment procedures which means a significant reduction of calibration effort.

  20. Diffractive optical element embedded in silver-doped nanocomposite glass.

    PubMed

    Fleming, Lauren A H; Wackerow, Stefan; Hourd, Andrew C; Gillespie, W Allan; Seifert, Gerhard; Abdolvand, Amin

    2012-09-24

    A diffractive optical element is fabricated with relative ease in a glass containing spherical silver nanoparticles 30 to 40 nm in diameter and embedded in a surface layer of thickness ~10 μm. The nanocomposite was sandwiched between a mesh metallic electrode with a lattice constant 2 μm, facing the nanoparticle containing layer and acting as an anode, and a flat metal electrode as cathode. Applying moderate direct current electric potentials of 0.4 kV and 0.6 kV at an elevated temperature of 200 °C for 30 minutes across the nanocomposites led to the formation of a periodic array of embedded structures of metallic nanoparticles. The current-time dynamics of the structuring processes, optical analyses of the structured nanocomposites and diffraction pattern of one such fabricated element are presented. PMID:23037407

  1. Discussion of the finite element method in optical diffraction tomography

    NASA Astrophysics Data System (ADS)

    Lobera, Julia; Coupland, Jeremy

    2006-04-01

    In Optical Diffraction Tomography (ODT) the refractive index is reconstructed from images with different illuminating wavefronts. In most cases the Born approximation is assumed, although this limits the applicability of the technique to weak-scattering problems. In this work we examine the scattering problem from first principles beginning from the Helmholtz equation that governs scalar diffraction and wave propagation. We demonstrate the use of the Born approximation and show typical errors when it is applied in practice. Solution of the Helmholtz equation using a Finite Element Method (FEM) with an appropriate Absorbing Boundary Condition (ABC) is described, and a non-linear optimization technique, the Conjugate Gradient Method (CGM), previously proposed for microwave imaging, is applied to the inverse problem.

  2. Design of diffractive optical surfaces within the SMS design method

    NASA Astrophysics Data System (ADS)

    Mendes-Lopes, João.; Benítez, Pablo; Miñano, Juan C.

    2015-08-01

    The Simultaneous Multiple Surface (SMS) method was initially developed as a design method in Nonimaging Optics and later, the method was extended for designing Imaging Optics. We present the extension of the SMS method to design diffractive optical surfaces. This method involves the simultaneous calculation of N/2 diffractive surfaces, using the phase-shift properties of diffractive surfaces as an extra degree of freedom, such that N one-parameter wavefronts can be perfectly coupled. Moreover, the SMS method for diffractive surfaces is a direct method, i.e., it is not based in multi-parametric optimization techniques. Representative diffractive systems designed by the SMS method are presented.

  3. Implementation of ordinary and extraordinary beams interference by application of diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Khonina, S. N.; Karpeev, S. V.; Morozov, A. A.; Paranin, V. D.

    2016-07-01

    We apply diffractive optical elements in problems of transformation of Bessel beams in a birefringent crystal. Using plane waves expansion we show a significant interference between the ordinary and extraordinary beams due to the energy transfer in the orthogonal transverse components in the nonparaxial mode. A comparative analysis of the merits and lack of diffractive and refractive axicons in problems of formation non-paraxial Bessel beams has shown the preferability of diffractive optics application in crystal optics. The transformation of uniformly polarised Bessel beams in the crystal of Iceland spar in the nonparaxial mode by application of a diffractive axicon is investigated numerically and experimentally.

  4. The effect of machining error on the diffraction efficiency of refraction and diffractive optical element

    NASA Astrophysics Data System (ADS)

    Gao, Long; Xue, Changxi; Yang, Hongfang; Nie, Xin

    2014-08-01

    According to the expression of the phase delay and diffraction efficiency of the diffractive optical elements(DOEs), the expression of diffraction efficiency of refraction and diffractive optical element with the tilt and decenter error in fabrication process was presented in this paper. Analysis results show, in the wavelength band of 501nm-554nm, the cycle of 500μm, the center wavelength of 521nm, when the tilt angleα increases form 0° to9.8° , the diffraction efficiency is above 99%; when the tilt angleα increases form 9.8° to 29.7° , diffraction efficiency is above 92.5%; when the tilt angleα is above 29.7° , the diffraction efficiency declines rapidly, diffraction efficiency is 0 when the tilt angleα is above 58° . When the decenter Δ increases form 0nm to 21.6μm,the diffraction efficiency is above 98%; when the decenter Δ increases form 21.6nm to 63.3μm, the diffraction efficiency is above 90%; when the decenter Δ is above 63.3μm, the diffraction efficiency declines rapidly, diffraction efficiency is 0 when the he decenter Δ is above 241.7μm. To sum up the results of analysis,mathematical analysis model of the relationship between the decenter and tilt error of diffractive optical element in processing and the diffraction efficiency can be used to guide the design of the refraction and diffractive hybrid optical system comprising the diffractive optical element.

  5. Optical system storage design with diffractive optical elements

    NASA Technical Reports Server (NTRS)

    Kostuk, Raymond K.; Haggans, Charles W.

    1993-01-01

    Optical data storage systems are gaining widespread acceptance due to their high areal density and the ability to remove the high capacity hard disk from the system. In magneto-optical read-write systems, a small rotation of the polarization state in the return signal from the MO media is the signal which must be sensed. A typical arrangement used for detecting these signals and correcting for errors in tracking and focusing on the disk is illustrated. The components required to achieve these functions are listed. The assembly and alignment of this complex system has a direct impact on cost, and also affects the size, weight, and corresponding data access rates. As a result, integrating these optical components and improving packaging techniques is an active area of research and development. Most designs of binary optic elements have been concerned with optimizing grating efficiency. However, rigorous coupled wave models for vector field diffraction from grating surfaces can be extended to determine the phase and polarization state of the diffracted field, and the design of polarization components. A typical grating geometry and the phase and polarization angles associated with the incident and diffracted fields are shown. In our current stage of work, we are examining system configurations which cascade several polarization functions on a single substrate. In this design, the beam returning from the MO disk illuminates a cascaded grating element which first couples light into the substrate, then introduces a quarter wave retardation, then a polarization rotation, and finally separates s- and p-polarized fields through a polarization beam splitter. The input coupler and polarization beam splitter are formed in volume gratings, and the two intermediate elements are zero-order elements.

  6. Tolerance analysis of multilayer diffractive optics based on polychromatic integral diffraction efficiency.

    PubMed

    Mao, Shan; Cui, Qingfeng; Piao, Mingxu

    2015-11-10

    Multilayer diffractive optical elements (MLDOEs) can achieve high diffraction efficiency for broadband wavelength. Polychromatic integral diffraction efficiency (PIDE) is the key concern for evaluating diffraction efficiency over the waveband. The modulation transfer function of a hybrid refractive-diffractive optical system is directly affected by the PIDE. The relationship between PIDE and continuous manufacturing errors for microstructure heights and periodic widths of MLDOEs is studied theoretically in this paper, and an example of MLDOEs is discussed in the visible waveband. The analysis results can be used for manufacturing error control in microstructure heights and periodic widths. PMID:26560782

  7. Fabrication and applications of large aperture diffractive optics

    SciTech Connect

    Dixit, S; Britten, J B; Hyde, R; Rushford, M; Summers, L; Toeppen, J

    2002-02-19

    Large aperture diffractive optics are needed in high power laser applications to protect against laser damage during operation and in space applications to increase the light gathering power and consequently the signal to noise. We describe the facilities we have built for fabricating meter scale diffractive optics and discuss several examples of these.

  8. Diffractive Elements in the Optical System: Successes, Challenges, and Solutions

    NASA Astrophysics Data System (ADS)

    Greisukh, G. I.; Ezhov, E. G.; Levin, I. A.; Kazin, S. V.; Stepanov, S. A.

    2015-01-01

    Correction of aberrations is regarded as one of the most successful applications of diffractive optical elements in the optical system. The ways of overcoming these negative properties of the diffractive elements as spherochromatism and power spectral selectivity are presented. Using the technique given in this paper, a compact plastic-lens refractive-diffractive objective, which can operate in a wide spectral range including the visible and near-infrared radiation, has been designed.

  9. Diffractive optics technology and the NASA Geostationary Earth Observatory (GEO)

    NASA Technical Reports Server (NTRS)

    Morris, G. Michael; Michaels, Robert L.; Faklis, Dean

    1992-01-01

    Diffractive (or binary) optics offers unique capabilities for the development of large-aperture, high-performance, light-weight optical systems. The Geostationary Earth Observatory (GEO) will consist of a variety of instruments to monitor the environmental conditions of the earth and its atmosphere. The aim of this investigation is to analyze the design of the GEO instrument that is being proposed and to identify the areas in which diffractive (or binary) optics technology can make a significant impact in GEO sensor design. Several potential applications where diffractive optics may indeed serve as a key technology for improving the performance and reducing the weight and cost of the GEO sensors have been identified. Applications include the use of diffractive/refractive hybrid lenses for aft-optic imagers, diffractive telescopes for narrowband imaging, subwavelength structured surfaces for anti-reflection and polarization control, and aberration compensation for reflective imaging systems and grating spectrometers.

  10. Diffractive optical elements for transformation of modes in lasers

    DOEpatents

    Sridharan, Arun K.; Pax, Paul H.; Heebner, John E.; Drachenberg, Derrek R.; Armstrong, James P.; Dawson, Jay W.

    2015-09-01

    Spatial mode conversion modules are described, with the capability of efficiently transforming a given optical beam profile, at one plane in space into another well-defined optical beam profile at a different plane in space, whose detailed spatial features and symmetry properties can, in general, differ significantly. The modules are comprised of passive, high-efficiency, low-loss diffractive optical elements, combined with Fourier transform optics. Design rules are described that employ phase retrieval techniques and associated algorithms to determine the necessary profiles of the diffractive optical components. System augmentations are described that utilize real-time adaptive optical techniques for enhanced performance as well as power scaling.

  11. Diffractive optical elements for transformation of modes in lasers

    DOEpatents

    Sridharan, Arun K; Pax, Paul H; Heebner, John E; Drachenberg, Derrek R.; Armstrong, James P.; Dawson, Jay W.

    2016-06-21

    Spatial mode conversion modules are described, with the capability of efficiently transforming a given optical beam profile, at one plane in space into another well-defined optical beam profile at a different plane in space, whose detailed spatial features and symmetry properties can, in general, differ significantly. The modules are comprised of passive, high-efficiency, low-loss diffractive optical elements, combined with Fourier transform optics. Design rules are described that employ phase retrieval techniques and associated algorithms to determine the necessary profiles of the diffractive optical components. System augmentations are described that utilize real-time adaptive optical techniques for enhanced performance as well as power scaling.

  12. Resonant diffraction gratings for spatial differentiation of optical beams

    SciTech Connect

    Golovastikov, N V; Bykov, D A; Doskolovich, L L

    2014-10-31

    Diffraction of a two-dimensional optical beam from a resonant diffraction grating is considered. It is shown that at certain resonance parameters the diffraction grating allows for spatial differentiation and integration of the incident beam. The parameters of the diffraction grating for spatial differentiation of optical beams in the transmission geometry are calculated. It is shown that the differentiating diffraction grating allows the conversion of the two-dimensional beam into the two-dimensional Hermite – Gaussian mode. The presented results of numerical modelling are in good agreement with the proposed theoretical description. The use of the considered resonant diffraction gratings is promising for solving the problems of all-optical data processing. (laser applications and other topics in quantum electronics)

  13. Fresnel-Kirchhoff theory applied to terrain diffraction problems

    NASA Astrophysics Data System (ADS)

    Whitteker, J. H.

    1990-09-01

    Fresnel-Kirchhoff theory is adapted to the problem of finding the diffraction attenuation at VHF and UHF over terrain profiles of arbitrary shape. Approximations are based on the assumptions of small wavelength and small diffraction angles. As a preliminary step, the theory is applied to the multiple-knife-edge problem. The field is found as a function of height above each knife edge in turn. In an application of Huygens' principle, an integration over the field above one knife edge provides the field at any point above the next. This formulation is equivalent to knife-edge formulations used in the past. Then each pair of neighboring knife edges is bridged with an imperfectly reflecting plane surface, representing the terrain. Huygens' principle is used again for the reflected wave, neglecting backscatter. The field found in this way is accurate for a good reflector but not a poor one. An analytical comparison shows agreement with rigorous diffraction theory for the problem of a plane wave incident on a perfectly reflecting wedge. Numerical comparisons with rigorous diffraction theory for a spherical Earth and for a small-radius hill (approximated with linear segments) show agreement to within 1.5 dB for the parameters chosen.

  14. Comparison of geometrical and diffraction optical transfer functions

    NASA Astrophysics Data System (ADS)

    Mahajan, Virendra N.; Díaz, José Antonio

    2015-09-01

    The geometrical and diffraction point-spread functions of an optical imaging system have been reviewed and compared in the past [V. N. Mahajan, "Comparison of geometrical and diffraction point-spread functions," SPIE Proc. 3729, 434-445 (1999)]. In this paper, we review and compare its corresponding optical transfer functions. While the truth lies with the diffraction OTF, it is considered easier and quicker to calculate the geometrical OTF, especially for large aberrations. We briefly describe the theory of the two OTFs, and explore the range of spatial frequencies and the magnitude of the primary aberrations over which the geometrical OTF may provide a reasonable approximation of the diffraction OTF.

  15. Diffractive optical interconnected multichip module: Demonstration and design

    NASA Astrophysics Data System (ADS)

    Morris, James Edward, Jr.

    2000-07-01

    Growth in the optical telecom and datacom industries is requiting new methods of manufacture in order to increase quantities by an order of magnitude while decreasing cost. An optical manufacturing approach utilizing wafer scale optics and integration of wafer scale electronics has potential of solving some of these manufacturing issues. An optical interconnected multichip module (OIMCM) is designed and manufactured to prove the technology. This OIMCM consists of integrated CMOS photodetectors, flip-chip compatible laser array chips, high efficiency diffractive optics, and flip-chip self- alignment for precision alignment of 1-2μm. A method to design a single diffractive surface to operate over a 25nm range in wavelength, typical of the variation in a laser diode, is presented. Also of importance is operation of optical systems over a temperature range. A novel method to athermalize an optical system with a laser diode is presented which utilizes a refractive surface and diffractive surface.

  16. Optical loss due to diffraction by concentrator Fresnel lenses

    SciTech Connect

    Hornung, Thorsten Nitz, Peter

    2014-09-26

    Fresnel lenses are widely used in concentrating photovoltaic (CPV) systems as a primary optical element. They focus sunlight on small solar cells or on the entrance apertures of secondary optical elements. A Fresnel lens consists of several prism rings and diffraction by these prism rings is unavoidable. Some of the light that would reach a designated target area according to geometric optics will miss it due to diffraction. This diffraction loss may be of relevant magnitude for CPV applications. The results of published analytical calculations are evaluated, discussed, and compared to computer simulations and measurements.

  17. Optical-diffraction method for determining crystal orientation

    DOEpatents

    Sopori, B.L.

    1982-05-07

    Disclosed is an optical diffraction technique for characterizing the three-dimensional orientation of a crystal sample. An arbitrary surface of the crystal sample is texture etched so as to generate a pseudo-periodic diffraction grating on the surface. A laser light beam is then directed onto the etched surface, and the reflected light forms a farfield diffraction pattern in reflection. Parameters of the diffraction pattern, such as the geometry and angular dispersion of the diffracted beam are then related to grating shape of the etched surface which is in turn related to crystal orientation. This technique may be used for examining polycrystalline silicon for use in solar cells.

  18. Analysis and optimal design of diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Rudnaya, Svetlana

    1999-12-01

    The problem we study arose in an industrial application. For an optical system, Diffractive Optical Elements (DOE) are used to produce a certain light intensity pattern in the near field. Of our particular interest is an Inverse problem: given a target image, determine the DOE configuration, e.g. thickness, that would produce this image. The problem can be complicated by specific constraints such as finite number of thickness levels that the DOE can have. Diffraction theory and Green's function approach are applied to construct a mathematical model for the light propagating through the DOE. Asymptotic methods of stationary phase and multiple-scale analysis are used to derive analytic solutions for periodic and quasi-periodic cases. These analytical expressions do not involve integration, save computational resources, and allow us to solve the Inverse problem analytically. Numerical results for particular applications are presented. The Inverse problem can be posed a large optimization problem with finite discrete variables, which can not be solved by traditional methods. We propose Genetic Algorithms based on analogies to natural evolution and representing a combination of random and directed search. A modification of the method that suits better to our problem, the Micro-Genetic Algorithm (MGA), is proposed. The MGA operates on a small set of potential solutions and restarts, using an adaptive mutation scheme, each time the local convergence is achieved. We prove convergence for the MGA using the Markov chain analysis. Numerical results of the MGA optimization are provided.

  19. Design of infrared diffractive telescope imaging optical systems

    NASA Astrophysics Data System (ADS)

    Zhang, ZhouFeng; Hu, BingLiang; Yin, QinYe; Xie, YongJun; Kang, FuZeng; Wang, YanJun

    2015-10-01

    Diffractive telescope is an updated imaging technology, it differs from conventional refractive and reflective imaging system, which is based on the principle of diffraction image. It has great potential for developing the larger aperture and lightweight telescope. However, one of the great challenges of design this optical system is that the diffractive optical element focuses on different wavelengths of light at different point in space, thereby distorting the color characteristics of image. In this paper, we designs a long-wavelength infrared diffractive telescope imaging system with flat surface Fresnel lens and cancels the infrared optical system chromatic aberration by another flat surface Fresnel lens, achieving broadband light(from 8μm-12μm) to a common focus with 4.6° field of view. At last, the diffuse spot size and MTF function provide diffractive-limited performance.

  20. Beyond the diffraction limit via optical amplification.

    PubMed

    Kellerer, Aglaé N; Ribak, Erez N

    2016-07-15

    In a previous article [Astron. Astrophys.561, A118 (2014)], we suggested a method to overcome the diffraction limit behind a telescope. We discuss and extend recent numerical simulations and test whether it is indeed possible to use photon amplification to enhance the angular resolution of a telescope or a microscope beyond the diffraction limit. An essential addition is the proposal to select events with an above-average ratio of stimulated to spontaneous photons. The analysis shows that the diffraction limit of a telescope is surpassed by a factor of 10 for an amplifier gain of 200, if the analysis is restricted to a tenth of the incoming astronomical photons. A gain of 70 is sufficient with a hundredth of the photons. More simulations must be performed to account for the bunching of spontaneous photons. PMID:27420490

  1. Tunable diffractive optical elements on various electro active polymers

    NASA Astrophysics Data System (ADS)

    Döring, Sebastian; Kollosche, Matthias; Hildebrandt, Niko; Stumpe, Joachim; Kofod, Guggi

    2010-05-01

    An innovative approach for voltage-tunable optical gratings based on dielectric elastomer actuators (DEAs) using electro active polymers is presented. Sinusoidal surface gratings, holographically written into azobenzene containing films, are transferred via nanoimprinting to DEAs of different carrier materials. We demonstrate that the surface relief deformation depends on the mechanical and geometrical properties of the actuators. The tested DEAs were made using commercially available elastomers, including a tri-block copolymer poly-styrene-ethylene-butadiene-styrene (SEBS), a silicone polydimethylsiloxane rubber (PDMS) and commonly used polyacrylic glue. The polyacrylic glue is ready to use, whereas the SEBS and the PDMS precursors have to be processed into thin films via different casting methods. The DEA material was pre-stretched, fixed to a stiff frame and coated with stretchable electrodes in appropriate designs. Since the actuation strain of the DEA depends strongly upon the conditions such as material properties, pre-stretch and geometry, the desired voltage-controllable deformations can be optimized during manufacturing of the DEA and also in the choice of materials in the grating transfer process. A full characterization of the grating deformation includes measurements of the grating pitch and depth modulation, plus the change of the diffraction angle and efficiency. The structural surface distortion was characterized by measuring the shape of the transmitted and diffracted laser beam with a beam profiling system while applying an electro-mechanical stress to the grating. Such surface distortions may lead to decreasing diffraction efficiency and lower beam quality. With properly chosen manufacturing parameters, we found a period shift of up to 9 % in a grating with 1 μm pitch. To describe the optical behavior, a model based on independently measured material parameters is presented.

  2. Optical diffractive elements for medical applications

    NASA Astrophysics Data System (ADS)

    Mikula, Grzegorz; Kolodziejczyk, Andrzej; Makowski, Michal; Sypek, Maciej

    2005-09-01

    We present a class of diffractive elements that can be used in medical applications. We describe their physical properties, in particular the point spread functions and modulation transfer functions. Our analyses consist of the detailed numerical simulations. The obtained results correspond to the different setup parameters and confirm usefulness of such structures in medical aspect, especially in presbyopia treatment.

  3. Diffraction from tunable periodic structures: application for the determination of electro-optic coefficients.

    PubMed

    Yang, X; Wood, L T; Miller, J H

    2001-11-01

    We discuss a method for measuring electro-optic coefficients by measuring diffraction from a tunable grating. The method involves measuring the changes in the diffraction pattern of a reflection grating, where applied electric fields of alternating direction induce changes in the index of refraction through the electro-optic effect. For certain geometries, these applied fields cause period-doubling effects that produce new peaks in the diffraction pattern. Numerically calculated diffraction patterns are presented for the assumptions of both homogeneous and inhomogeneous fields. Peak splitting, as a function of both the number of slits illuminated and the induced change in the index of refraction, is observed and discussed. Finally, the usefulness of our method for the measurement of electro-optic coefficients is discussed. PMID:18364844

  4. DiffractX: A Simulation Toolbox for Diffractive X-ray Optics

    NASA Astrophysics Data System (ADS)

    Selin, M.; Bertilson, M.; Nilsson, D.; von Hofsten, O.; Hertz, H. M.; Vogt, U.

    2011-09-01

    X-ray wavefront propagation is a powerful technique when simulating the performance of x-ray optical components. Using various numerical methods, interesting parameters such as focusing capability and efficiency can be investigated. Here we present the toolbox DiffractX, implemented in MATLAB. It contains many different wave propagation methods for the simulation of diffractive x-ray optics, including Fresnel propagation, the finite difference method (FDM), the thin object approximation, the rigorous coupled wave theory (RCWT), and the finite element method (FEM). All tools are accessed through a graphical interface, making the design of simulations fast and intuitive, even for users with little or no programming experience. The tools have been utilized to characterize realistic as well as idealized optical components. This will aid further developments of diffractive x-ray optics.

  5. Dual focus diffractive optical element with extended depth of focus

    NASA Astrophysics Data System (ADS)

    Uno, Katsuhiro; Shimizu, Isao

    2014-09-01

    A dual focus property and an extended depth of focus were verified by a new type of diffractive lens displaying on liquid crystal on silicon (LCoS) devices. This type of lens is useful to read information on multilayer optical discs and tilted discs. The radial undulation of the phase groove on the diffractive lens gave the dual focus nature. The focal extension was performed by combining the dual focus lens with the axilens that was invented for expanding the depth of focus. The number of undulations did not affect the intensity along the optical axis but the central spot of the diffraction pattern.

  6. Optical-image transfer through a diffraction-compensating metamaterial.

    PubMed

    Kivijärvi, Ville; Nyman, Markus; Shevchenko, Andriy; Kaivola, Matti

    2016-05-01

    Cancellation of optical diffraction is an intriguing phenomenon enabling optical fields to preserve their transverse intensity profiles upon propagation. In this work, we introduce a metamaterial design that exhibits this phenomenon for three-dimensional optical beams. As an advantage over other diffraction-compensating materials, our metamaterial is impedance-matched to glass, which suppresses optical reflection at the glass-metamaterial interface. The material is designed for beams formed by TM-polarized plane-wave components. We show, however, that unpolarized optical images with arbitrary shapes can be transferred over remarkable distances in the material without distortion. We foresee multiple applications of our results in integrated optics and optical imaging. PMID:27137594

  7. Active learning in optics and photonics: Fraunhofer diffraction

    NASA Astrophysics Data System (ADS)

    Ghalila, H.; Ben Lakhdar, Z.; Lahmar, S.; Dhouaidi, Z.; Majdi, Y.

    2014-07-01

    "Active Learning in Optics and Photonics" (ALOP), funded by UNESCO within its Physics Program framework with the support of ICTP (Abdus Salam International Centre for Theoretical Physics) and SPIE (Society of Photo-Optical Instrumentation Engineers), aimed to helps and promotes a friendly and interactive method in teaching optics using simple and inexpensive equipment. Many workshops were organized since 2005 the year when Z. BenLakhdar, whom is part of the creators of ALOP, proposed this project to STO (Société Tunisienne d'Optique). These workshops address several issues in optics, covering geometrical optics, wave optics, optical communication and they are dedicated to both teachers and students. We focus this lecture on Fraunhofer diffraction emphasizing the facility to achieve this mechanism in classroom, using small laser and operating a slit in a sheet of paper. We accompany this demonstration using mobile phone and numerical modeling to assist in the analysis of the diffraction pattern figure.

  8. Optical laue diffraction on photonic structures designed by laser lithography

    NASA Astrophysics Data System (ADS)

    Samusev, K. B.; Rybin, M. V.; Lukashenko, S. Yu.; Limonov, M. F.

    2016-06-01

    Two-dimensional photonic crystals with square symmetry C 4v were obtained using the laser lithography method. The structure of these samples was studied by scanning electron microscopy. Optical Laue diffraction for monochromatic light was studied experimentally depending on the incidence angle of laser beam and lattice constant. Interpretation of the observed diffraction patterns is given in the framework of the Laue diffraction mechanism for an one-dimensional chain of scattering elements. Red thresholds for different diffraction orders were determined experimentally and theoretically. The results of calculations are in an excellent agreement with experiment.

  9. Optical theorem for acoustic non-diffracting beams and application to radiation force and torque

    PubMed Central

    Zhang, Likun; Marston, Philip L.

    2013-01-01

    Acoustical and optical non-diffracting beams are potentially useful for manipulating particles and larger objects. An extended optical theorem for a non-diffracting beam was given recently in the context of acoustics. The theorem relates the extinction by an object to the scattering at the forward direction of the beam’s plane wave components. Here we use this theorem to examine the extinction cross section of a sphere centered on the axis of the beam, with a non-diffracting Bessel beam as an example. The results are applied to recover the axial radiation force and torque on the sphere by the Bessel beam. PMID:24049681

  10. Linearization of an annular image by using a diffractive optic

    NASA Technical Reports Server (NTRS)

    Matthys, Donald R.

    1996-01-01

    The goal for this project is to develop the algorithms for fracturing the zones defined by the mapping transformation, and to actually produce the binary optic in an appropriate setup. In 1984 a side-viewing panoramic viewing system was patented, consisting of a single piece of glass with spherical surfaces which produces a 360 degree view of the region surrounding the lens which extends about 25 degrees in front of and 20 degrees behind the lens. The system not only produces images of good quality, it is also afocal, i.e., images stay in focus for objects located right next to the lens as well as those located far from the lens. The lens produced a panoramic view in an annular shaped image, and so the lens was called a PAL (panoramic annular lens). When applying traditional measurements to PAL images, it is found advantageous to linearize the annular image. This can easily be done with a computer and such a linearized image can be produced within about 40 seconds on current microcomputers. However, this process requires a frame-grabber and a computer, and is not real-time. Therefore, it was decided to try to perform this linearization optically by using a diffractive optic.

  11. Dedicated software for diffractive optics design and simulation

    NASA Astrophysics Data System (ADS)

    Firsov, A.; Brzhezinskaya, M.; Firsov, A.; Svintsov, A.; Erko, A.

    2013-03-01

    An efficient software package for the structure design and simulation of imaging properties of diffraction optical elements has been developed. It operates with point source and consists of: the ZON software, to calculate the structure of an optical element in transmission and reflection; the KRGF software, to simulate the diffraction properties of an ideal optical element with point source; the DS software, to calculate the diffraction properties by taking into consideration material and shadowing effects. Optional software allows simulation with a real non-point source. Zone plate thickness profile, source shape as well as substrate curvature are considered in this calculation. This is especially important for the diffractive focusing elements and gratings at a total external reflection, given that the lateral size of the structure can be up to 1 m. The program package can be used in combination with the Nanomaker software to prepare data for ion and e-beam surface modifications and corrections.

  12. Stratified Diffractive Optic Approach for Creating High Efficiency Gratings

    NASA Technical Reports Server (NTRS)

    Chambers, Diana M.; Nordin, Gregory P.

    1998-01-01

    Gratings with high efficiency in a single diffracted order can be realized with both volume holographic and diffractive optical elements. However, each method has limitations that restrict the applications in which they can be used. For example, high efficiency volume holographic gratings require an appropriate combination of thickness and permittivity modulation throughout the bulk of the material. Possible combinations of those two characteristics are limited by properties of currently available materials, thus restricting the range of applications for volume holographic gratings. Efficiency of a diffractive optic grating is dependent on its approximation of an ideal analog profile using discrete features. The size of constituent features and, consequently, the number that can be used within a required grating period restricts the applications in which diffractive optic gratings can be used. These limitations imply that there are applications which cannot be addressed by either technology. In this paper we propose to address a number of applications in this category with a new method of creating high efficiency gratings which we call stratified diffractive optic gratings. In this approach diffractive optic techniques are used to create an optical structure that emulates volume grating behavior. To illustrate the stratified diffractive optic grating concept we consider a specific application, a scanner for a space-based coherent wind lidar, with requirements that would be difficult to meet by either volume holographic or diffractive optic methods. The lidar instrument design specifies a transmissive scanner element with the input beam normally incident and the exiting beam deflected at a fixed angle from the optical axis. The element will be rotated about the optical axis to produce a conical scan pattern. The wavelength of the incident beam is 2.06 microns and the required deflection angle is 30 degrees, implying a grating period of approximately 4 microns

  13. Phase encryption of biometrics in diffractive optical elements.

    PubMed

    Johnson, E G; Brasher, J D

    1996-08-15

    A new technique for the optical encoding of images is presented. The method of generalized projections is used to design diffractive optical elements for the phase encryption of biometrics for security applications. The encryption algorithm converges rapidly, and the decryption is seen to be secure and tolerant to additive noise. PMID:19876322

  14. Phase encryption of biometrics in diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Johnson, E. G.; Brasher, J. D.

    1996-08-01

    A new technique for the optical encoding of images is presented. The method of generalized projections is used to design diffractive optical elements for the phase encryption of biometrics for security applications. The encryption algorithm converges rapidly, and the decryption is seen to be secure and tolerant to additive noise.

  15. Diffractive optical element with same diffraction pattern for multicolor light-emitting diodes.

    PubMed

    Chen, Mengzhu; Wang, Qixia; Gu, Huarong; Tan, Qiaofeng

    2016-01-01

    The wavelength-division multiplexing technique can be utilized in visible light communication to increase the channel capacity when a multicolor mixed white LED is used as light source. In such an application, the illumination area of LEDs should be invariant to the incident wavelength, so as to decrease interference within the adjacent regions. Diffractive optical elements (DOEs) can be used in the optical transmitter system to shape the diffraction patterns into polygons. However, traditional DOEs illuminated by a multicolor mixed white LED would result into diffraction patterns with unequal sizes. In this paper, a hybrid algorithm which combines particle swarm optimization with a genetic algorithm is proposed for multicolor oriented DOEs design. A DOE is designed and fabricated for blue and red LEDs, and experimental results show that diffraction patterns with rather good uniformity as well as quasi-equal size for red and blue LEDs are obtained. PMID:26835636

  16. Photoacoustic tomography: Ultrasonically beating optical diffusion and diffraction

    NASA Astrophysics Data System (ADS)

    Wang, Lihong

    2014-03-01

    A decade of research has pushed photoacoustic computed tomography to the forefront of molecular-level imaging, notes SPIE Fellow Lihong Wang (Washington University, St. Louis) in his plenary talk, "Photoacoustic Tomography: Ultrasonically Beating Optical Diffusion and Diffraction." Modern optical microscopy has resolution and diffraction limitations. But noninvasive functional photoacoustic computed tomography has overcome this limit, offering deep penetration with optical contrast and ultrasonic resolution of 1 cm depth or more -- up to 7 cm of penetration in some cases, such as evaluating sentinel lymph nodes for breast cancer staging. This opens up applications in whole body imaging, brain function, oxygen saturation, label-free cell analysis, and noninvasive cancer biopsies.

  17. Nonreciprocal optical diffraction by a single layer of gyromagnetic cylinders.

    PubMed

    Guo, Tian-Jing; Li, Teng-Fei; Yang, Mu; Cui, Hai-Xu; Guo, Qing-Hua; Cao, Xue-Wei; Chen, Jing

    2014-01-13

    We study the diffraction of optical waves by a single layer of gyromagnetic cylinders. We show that a nonvanishing rotating dipole momentum is excited in a single gyromagnetic cylinder because of the classic analog of the Zeeman effect on photonic angular momentum states (PAMSs). Consequently, different collective dipole modes are excited in a gyromagnetic cylinder array at opposite incident angles. Nonreciprocal optical diffraction effects can be observed, where the transmission and reflection coefficients depend on the sign of the incident angle. A novel phenomenon of nonreciprocal negative directional transmission is demonstrated and numerically analyzed. This work highlights the potential of PAMSs in manipulating the propagation of optical waves for various applications. PMID:24515014

  18. Role of photonic angular momentum states in nonreciprocal diffraction from magneto-optical cylinder arrays

    SciTech Connect

    Guo, Tian-Jing; Wu, Li-Ting; Yang, Mu; Guo, Rui-Peng; Cui, Hai-Xu; Chen, Jing

    2014-07-15

    Optical eigenstates in a concentrically symmetric resonator are photonic angular momentum states (PAMSs) with quantized optical orbital angular momentums (OAMs). Nonreciprocal optical phenomena can be obtained if we lift the degeneracy of PAMSs. In this article, we provide a comprehensive study of nonreciprocal optical diffraction of various orders from a magneto-optical cylinder array. We show that nonreciprocal diffraction can be obtained only for these nonzero orders. Role of PAMSs, the excitation of which is sensitive to the directions of incidence, applied magnetic field, and arrangement of the cylinders, are studied. Some interesting phenomena such as a dispersionless quasi-omnidirectional nonreciprocal diffraction and spikes associated with high-OAM PAMSs are present and discussed.

  19. Transferring diffractive optics from research to commercial applications: Part I - progress in the patent landscape

    NASA Astrophysics Data System (ADS)

    Brunner, Robert

    2013-12-01

    In the last 20 years, diffractive optics experienced a strong research interest and was in the center of many development projects in applied optics. To offer a side view for optical engineers, here, we discuss selected, business-related aspects of the current status of the transfer process to bring diffractive optics into commercial products. The contribution is divided into two parts. Here, in part I, we focus on the patent landscape of diffractive optics with a closer look on the temporal development and the distribution over main players. As an important result, currently, new strong patent activities are observed especially in the context of imaging systems. In the second part, the business volumes of selected market segments are discussed.

  20. Diffractive Optics From Self-Assembled DNA

    PubMed Central

    Levine, Zachary H.

    2002-01-01

    An algorithm is presented for assembling tiles into a variable spaced grating, the one-dimensional analog of a Fresnel zone plate. The algorithm supports multi-level gratings. The x-ray properties of such a grating, assumed to be constructed from DNA are estimated, leading to the conclusion that thick structures may be useful for intermediate energy x rays, but that thin structures for soft x rays are best used as disposable masks. The diffraction of cold, coherent atoms is a plausible application for single layer stencils.

  1. Diffractive optical element for creating visual 3D images.

    PubMed

    Goncharsky, Alexander; Goncharsky, Anton; Durlevich, Svyatoslav

    2016-05-01

    A method is proposed to compute and synthesize the microrelief of a diffractive optical element to produce a new visual security feature - the vertical 3D/3D switch effect. The security feature consists in the alternation of two 3D color images when the diffractive element is tilted up/down. Optical security elements that produce the new security feature are synthesized using electron-beam technology. Sample optical security elements are manufactured that produce 3D to 3D visual switch effect when illuminated by white light. Photos and video records of the vertical 3D/3D switch effect of real optical elements are presented. The optical elements developed can be replicated using standard equipment employed for manufacturing security holograms. The new optical security feature is easy to control visually, safely protected against counterfeit, and designed to protect banknotes, documents, ID cards, etc. PMID:27137530

  2. Diffraction efficiency sensitivity to oblique incident angle for multilayer diffractive optical elements.

    PubMed

    Yang, Hongfang; Xue, Changxi; Li, Chuang; Wang, Ju; Zhang, Ran

    2016-09-01

    The relationship between diffraction efficiency of multilayer diffractive optical elements (MLDOEs) and arbitrary incident angle was numerically analyzed with the effective area method. The method is based on the shield effect between two elements of MLDOEs; a generalized diffraction efficiency formulation was obtained in a wide range of tilt angles, which overcame the limitations of scalar diffraction theory when the period width of MLDOEs is taken into account. A detailed comparison of the proposed effective area method with the scalar diffraction theory is numerically presented for MLDOEs. The validity of the proposed method is verified by comparison with the rigorous electromagnetic analysis method, especially the finite-difference time-domain method. The analysis results show that the shield effect augments with the increase of the incident angles; the effect of incident angles on MLDOEs with finite period widths is more noticeable than that with large period widths. PMID:27607291

  3. Diffraction-limited high-finesse optical cavities

    SciTech Connect

    Kleckner, Dustin; Irvine, William T. M.; Oemrawsingh, Sumant S. R.; Bouwmeester, Dirk

    2010-04-15

    High-quality optical cavities with wavelength-sized end mirrors are important to the growing field of micro-optomechanical systems. We present a versatile method for calculating the modes of diffraction limited optical cavities and show that it can be used to determine the effect of a wide variety of cavity geometries and imperfections. Additionally, we show these calculations agree remarkably well with FDTD simulations for wavelength-sized optical modes, even though our method is based on the paraxial approximation.

  4. The impact of novel 3D diffraction optics development

    NASA Astrophysics Data System (ADS)

    Firsov, Alexander; Brzhezinskaya, Maria; Loechel, Heike; Siewert, Frank; Erko, Alexei

    2013-05-01

    Dedicated diffractive VUV- and X-ray optical elements are essential for future developments in synchrotron instrumentation and methods like e.g. time-resolved spectroscopy. The quality of optical components like gratings or diffractive focusing elements matters directly to the results achievable. On the other hand the availability of such optical components is very limited at present. In this contribution we report on the development of new methods of time-resolved x-ray spectroscopy based on novel 3D diffractive optical elements (DOE) with a unique combination of properties. Such optical elements are of highest interest for application in modern synchrotron facilities like Free Electron Lasers (FELs) as well as for laboratory facilities with high harmonic generators (HHG). The project includes theoretical work as well as the development of a dedicated technology, including metrology, to manufacture such type of optics for applications in atomic, molecular and condensed matter physics. The here discussed type of optics was successfully implemented for soft-X-ray-application at the femto-second-slicing beamline at BESSY II storage ring of the Helmholtz Zentrum Berlin. DOE are expected to be important components in beamlines at upcoming new high brilliance X-ray sources such as FELs. The application of DOE`s allows to reduce the number of optical elements in a beamline. Thus allow to provide the highest possible transmission and flux as well as preserving the unique properties of FEĹs, like wave-front and coherence.

  5. Optical refractometry based on Fresnel diffraction from a phase wedge.

    PubMed

    Tavassoly, M Taghi; Saber, Ahad

    2010-11-01

    A method that utilizes the Fresnel diffraction of light from the phase step formed by a transparent wedge is introduced for measuring the refractive indices of transparent solids, liquids, and solutions. It is shown that, as a transparent wedge of small apex angle is illuminated perpendicular to its surface by a monochromatic parallel beam of light, the Fresnel fringes, caused by abrupt change in refractive index at the wedge lateral boundary, are formed on a screen held perpendicular to the beam propagation direction. The visibility of the fringes varies periodically between zero and 1 in the direction normal to the wedge apex. For a known or measured apex angle, the wedge refractive index is obtained by measuring the period length by a CCD. To measure the refractive index of a transparent liquid or solution, the wedge is installed in a transparent rectangle cell containing the sample. Then, the cell is illuminated perpendicularly and the visibility period is measured. By using modest optics, one can measure the refractive index at a relative uncertainty level of 10(-5). There is no limitation on the refractive index range. The method can be applied easily with no mechanical manipulation. The measuring apparatus can be very compact with low mechanical and optical noises. PMID:21042389

  6. Optical Alignment and Diffraction Analysis for AIRES: An Airborne Infrared Echelle Spectrometer

    NASA Technical Reports Server (NTRS)

    Haas, Michael R.; Fonda, Mark (Technical Monitor)

    2002-01-01

    The optical design is presented for a long-slit grating spectrometer known as AIRES (Airborne InfraRed Echelle Spectrometer). The instrument employs two gratings in series: a small order sorter and a large steeply blazed echelle. The optical path includes four pupil and four field stops, including two narrow slits. A detailed diffraction analysis is performed using GLAD by Applied Optics Research to evaluate critical trade-offs between optical throughput, spectral resolution, and system weight and volume. The effects of slit width, slit length, oversizing the second slit relative to the first, on- vs off-axis throughput, and clipping at the pupil stops and other optical elements are discussed.

  7. Optical metrology for immersed diffractive multifocal ophthalmic intracorneal lenses

    NASA Astrophysics Data System (ADS)

    Tankam, P.; Lépine; Castignoles, F.; Chavel, P.

    2012-09-01

    This paper deals with the optical characterization of diffractive multifocal Intra-Corneal Lenses (ICLs) that we have developed in order to correct presbyopia. These diffractive multifocal lenses are made of a very soft material (permeable to oxygen and nutrients), with a thickness smaller than 100 μm and require liquid immersion. As a consequence, most of the conventional metrology methods are unsuited for their characterization. We developed specific setups to measure diffractive efficiencies and Modulation Transfer Function (MTF) adapted to such components. Experimental results are in good agreement with Zema's simulations. For the best of our knowledge, it is the first time that optical characterization is devoted to the ICLs. Furthermore, most of the IOL's optical characterizations are focused on far vision MTF and don't assess the near vision MTF, which we study in this paper.

  8. Design and Analysis of Single and Cascaded Diffractive Optical Elements

    NASA Astrophysics Data System (ADS)

    Johnson, Eric Gordon

    The design of complex diffractive optical elements requires both a mathematical formulation of the problem and the appropriate optimization method. The mathematical formulations are very complex, since in some circumstances scalar based strategies are acceptable, whereas, in other cases exact solutions to Maxwell's equations are required. Once the mathematical formulations are coupled with the appropriate optimization algorithms, then the design of single and cascaded diffractive optical elements can be exploited. This Dissertation develops the mathematical framework for diffractive optics utilizing scalar based design and exact solutions to complex periodic dielectric structures. Additionally, a new method of optimization is introduced which is based on the foundations of genetics. This methodology is used to design unique elements for wavefront splitting, polarization filtering, and wavelength filtering. An additional algorithm is developed for scalar based solutions using variants of existing methods, resulting in some interesting designs concerning data encryption and beam shaping.

  9. Optical Tweezers for Sample Fixing in Micro-Diffraction Experiments

    SciTech Connect

    Amenitsch, H.; Rappolt, M.; Sartori, B.; Laggner, P.; Cojoc, D.; Ferrari, E.; Garbin, V.; Di Fabrizio, E.; Burghammer, M.; Riekel, Ch.

    2007-01-19

    In order to manipulate, characterize and measure the micro-diffraction of individual structural elements down to single phospholipid liposomes we have been using optical tweezers (OT) combined with an imaging microscope. We were able to install the OT system at the microfocus beamline ID13 at the ESRF and trap clusters of about 50 multi-lamellar liposomes (< 10 {mu}m large cluster). Further we have performed a scanning diffraction experiment with a 1 micrometer beam to demonstrate the fixing capabilities and to confirm the size of the liposome cluster by X-ray diffraction.

  10. Optical cryptography topology based on a three-dimensional particle-like distribution and diffractive imaging.

    PubMed

    Chen, Wen; Chen, Xudong

    2011-05-01

    In recent years, coherent diffractive imaging has been considered as a promising alternative for information retrieval instead of conventional interference methods. Coherent diffractive imaging using the X-ray light source has opened up a new research perspective for the measurement of non-crystalline and biological specimens, and can achieve unprecedentedly high resolutions. In this paper, we show how a three-dimensional (3D) particle-like distribution and coherent diffractive imaging can be applied for a study of optical cryptography. An optical multiple-random-phase-mask encoding approach is used, and the plaintext is considered as a series of particles distributed in a 3D space. A topology concept is also introduced into the proposed optical cryptosystem. During image decryption, a retrieval algorithm is developed to extract the plaintext from the ciphertexts. In addition, security and advantages of the proposed optical cryptography topology are also analyzed. PMID:21643154

  11. Research on the Design of an Optical Information Storage Sensing System Using a Diffractive Optical Element

    PubMed Central

    Cheng, Xuemin; Hao, Qun; Hou, Jianbo; Li, Xiangping; Ma, Jianshe; Gu, Min

    2013-01-01

    This paper introduces a compact optical information storage sensing system. Applications of this system include longitudinal surface plasmon resonance detection of gold nanorods with a single femtosecond laser in three-dimensional space as well as data storage. A diffractive optical element (DOE) is applied in the system to separate the recording-reading beam from the servo beam. This allows us to apply a single laser and one objective lens in a single optical path for the servo beam and the recording-reading beam. The optical system has a linear region of 8 λ, which is compatible with current DVD servo modules. The wavefront error of the optical system is below 0.03 λrms. The minimum grating period of the DOE is 13.4 μm, and the depth of the DOE is 1.2 μm, which makes fabrication of it possible. The DOE is also designed to conveniently control the layer-selection process, as there is a linear correlation between the displacement of the DOE and the layer-selection distance. The displacement of DOE is in the range of 0–6.045 mm when the thickness of the layer-selection is 0.3 mm. Experiments were performed and the results have been verified. PMID:24217360

  12. Diffractive micro-optical element with nonpoint response

    NASA Astrophysics Data System (ADS)

    Soifer, Victor A.; Golub, Michael A.

    1993-01-01

    Common-use diffractive lenses have microrelief zones in the form of simple rings that provide only an optical power but do not contain any image information. They have a point-image response under point-source illumination. We must use a more complicated non-point response to focus a light beam into different light marks, letter-type images as well as for optical pattern recognition. The current presentation describes computer generation of diffractive micro- optical elements with complicated curvilinear zones of a regular piecewise-smooth structure and grey-level or staircase phase microrelief. The manufacture of non-point response elements uses the steps of phase-transfer calculation and orthogonal-scan masks generation or lithographic glass etching. Ray-tracing method is shown to be applicable in this task. Several working samples of focusing optical elements generated by computer and photolithography are presented. Using the experimental results we discuss here such applications as laser branding.

  13. A vectorial ray-based diffraction integral for optical systems

    NASA Astrophysics Data System (ADS)

    Andreas, Birk

    2015-09-01

    The propagation of coherent laser light in optical systems is simulated by the vectorial ray-based diffraction integral (VRBDI) method which utilizes vectorial diffraction theory, ray aiming, differential ray tracing and matrix optics. On a global scale the method is not restricted to the paraxial approximation, whereas it is properly used for a local representation of the wavefront close to an aimed detection location. First, the field of a monochromatic continuous wave on an input plane is decomposed into spherical or plane wave components. Then, these components are represented by aimed ray tubes and traced through an optical system. Finally, the contributions are added coherently on an output plane whose position has to be chosen according to ray-aiming requirements. Provided that the apertures in the optical system are large with respect to the wavelength the results are fairly accurate.

  14. Large Aperture Multiplexed Diffractive Lidar Optics

    NASA Technical Reports Server (NTRS)

    Rallison, Richard D.; Schwemmer, Geary K. (Technical Monitor)

    1999-01-01

    We have delivered only 2 or 3 UV Holographic Optical Elements (HOEs) thus far and have fallen short of the intended goal in size and in dual wavelength function. Looking back, it has been fortuitous that we even made anything work in the UV region. It was our good fortune to discover that the material we work with daily was adequate for use at 355 nm, if well rinsed during processing. If we had stuck to our original plan of etching in small pieces of fused silica, we would still be trying to make the first small section in our ion mill, which is not yet operational. The original plan was far too ambitious and would take another 2 years to complete beginning where we left off this time. In order to make a HOE for the IR as well as the UV we will likely have to learn to sensitize some film to the 1064 line and we have obtained sensitizer that is reported to work in that region already. That work would also take an additional year to complete.

  15. Diffractive optical elements for the production of synthetic spectra

    SciTech Connect

    Sinclair, M.B.; Butler, M.A.; Ricco, A.J.

    1997-03-01

    We demonstrate that computer-generated diffractive optical elements can be used to synthesize the infrared spectra of real compounds. In particular, we describe a modified phase-retrieval algorithm that we have used to design diffractive elements of this type and we present experimental results for a diffractive optic which is capable of synthesizing the infrared spectrum of HF between 3600 cm{sup -1} and 4300 cm{sup -1}. The reflection-mode diffractive optic consists of 4096 lines, each 4.5 {mu}m wide, at 16 discrete depths relative to the substrate (from 0 to 1.2 {mu}m), and was fabricated on a silicon wafer using anisotropic reactive ion-beam etching in a four-mask-level process. We propose the use of such elements to replace reference cells in a new type of correlation spectroscopy that we call {open_quotes}holographic correlation spectroscopy.{close_quotes} Storage of a large number of diffractive elements, each producing a synthetic spectrum corresponding to a different target compound, in compact disk-like format, will allow a spectrometer of this type to rapidly determine the composition of unknown samples. Further, this approach can be used to perform correlation-based measurements of hazardous or transient species, for which conventional correlation spectroscopy is impractical.

  16. Optical properties and diffraction effects in opal photonic crystals.

    PubMed

    Balestreri, Alessandra; Andreani, Lucio Claudio; Agio, Mario

    2006-09-01

    Optical properties of fcc opals oriented along the [111] direction are calculated by means of a scattering-matrix approach based on approximating each sphere with cylindrical slices. The use of a plane-wave basis in each layer allows distinguishing zero-order reflection and transmission from higher-order (diffraction) spectra. Optical spectra at large values of the angle of incidence indicate the presence of diffraction effects and of polarization mixing along the LW orientation. Reflectance and transmittance in the high-energy region show a rich spectral dependence and compare reasonably well with recent experimental observations on polystyrene opals. Diffraction spectra as a function of the number of layers display an oscillatory behavior, pointing to the existence of a Pendellösung phenomenon, related to the exchange of energy between two propagating modes in the investigated three-dimensional photonic crystal. This phenomenon could be observed in transmittance experiments on high-quality opals with controlled thickness. PMID:17025760

  17. Optical Simulation of Debye-Scherrer Crystal Diffraction

    ERIC Educational Resources Information Center

    Logiurato, F.; Gratton, L. M.; Oss, S.

    2008-01-01

    In this paper we describe and discuss simple, inexpensive optical experiments used to simulate x-ray and electron diffraction according to the Debye-Scherrer theory. The experiment can be used to address, at the high school level, important subjects related to fundamental quantum and solid-state physics.

  18. Teaching Diffraction with Hands-On Optical Spectrometry

    ERIC Educational Resources Information Center

    Fischer, Robert

    2012-01-01

    Although the observation of optical spectra is common practice in physics classes, students are usually limited to a passive, qualitative observation of nice colours. This paper discusses a diffraction-based spectrometer that allows students to take quantitative measurements of spectral bands. Students can build it within minutes from generic…

  19. Diffractive Optical Elements based in Diamond Like Carbon (DLC) films

    NASA Astrophysics Data System (ADS)

    Sparvoli, M. Marina; Mansano, Ronaldo D.

    2008-04-01

    In this work was developed a Diffractive Optical Elements (DOEs) based in amorphous hydrogenated carbon (Diamond Like Carbon) films. DOEs can be built in large scale with high reproducibility and eliminating almost stages used in optical elements tradicional fabrication, as abrasion and burnishing. These devices had been built by the etching of DLC deposited by sputtering process. The characterizations of these devices are realized by optical analyzes with a 633 nm HeNe laser. The DLC films roughness and etch rate after process were measured by high step meter.

  20. Optical diffraction for measurements of nano-mechanical bending.

    PubMed

    Hermans, Rodolfo I; Dueck, Benjamin; Ndieyira, Joseph Wafula; McKendry, Rachel A; Aeppli, Gabriel

    2016-01-01

    We explore and exploit diffraction effects that have been previously neglected when modelling optical measurement techniques for the bending of micro-mechanical transducers such as cantilevers for atomic force microscopy. The illumination of a cantilever edge causes an asymmetric diffraction pattern at the photo-detector affecting the calibration of the measured signal in the popular optical beam deflection technique (OBDT). The conditions that avoid such detection artefacts conflict with the use of smaller cantilevers. Embracing diffraction patterns as data yields a potent detection technique that decouples tilt and curvature and simultaneously relaxes the requirements on the illumination alignment and detector position through a measurable which is invariant to translation and rotation. We show analytical results, numerical simulations and physiologically relevant experimental data demonstrating the utility of the diffraction patterns. We offer experimental design guidelines and quantify possible sources of systematic error in OBDT. We demonstrate a new nanometre resolution detection method that can replace OBDT, where diffraction effects from finite sized or patterned cantilevers are exploited. Such effects are readily generalized to cantilever arrays, and allow transmission detection of mechanical curvature, enabling instrumentation with simpler geometry. We highlight the comparative advantages over OBDT by detecting molecular activity of antibiotic Vancomycin. PMID:27255427

  1. Optical diffraction for measurements of nano-mechanical bending

    NASA Astrophysics Data System (ADS)

    Hermans, Rodolfo I.; Dueck, Benjamin; Ndieyira, Joseph Wafula; McKendry, Rachel A.; Aeppli, Gabriel

    2016-06-01

    We explore and exploit diffraction effects that have been previously neglected when modelling optical measurement techniques for the bending of micro-mechanical transducers such as cantilevers for atomic force microscopy. The illumination of a cantilever edge causes an asymmetric diffraction pattern at the photo-detector affecting the calibration of the measured signal in the popular optical beam deflection technique (OBDT). The conditions that avoid such detection artefacts conflict with the use of smaller cantilevers. Embracing diffraction patterns as data yields a potent detection technique that decouples tilt and curvature and simultaneously relaxes the requirements on the illumination alignment and detector position through a measurable which is invariant to translation and rotation. We show analytical results, numerical simulations and physiologically relevant experimental data demonstrating the utility of the diffraction patterns. We offer experimental design guidelines and quantify possible sources of systematic error in OBDT. We demonstrate a new nanometre resolution detection method that can replace OBDT, where diffraction effects from finite sized or patterned cantilevers are exploited. Such effects are readily generalized to cantilever arrays, and allow transmission detection of mechanical curvature, enabling instrumentation with simpler geometry. We highlight the comparative advantages over OBDT by detecting molecular activity of antibiotic Vancomycin.

  2. Optical diffraction for measurements of nano-mechanical bending

    PubMed Central

    Hermans, Rodolfo I.; Dueck, Benjamin; Ndieyira, Joseph Wafula; McKendry, Rachel A.; Aeppli, Gabriel

    2016-01-01

    We explore and exploit diffraction effects that have been previously neglected when modelling optical measurement techniques for the bending of micro-mechanical transducers such as cantilevers for atomic force microscopy. The illumination of a cantilever edge causes an asymmetric diffraction pattern at the photo-detector affecting the calibration of the measured signal in the popular optical beam deflection technique (OBDT). The conditions that avoid such detection artefacts conflict with the use of smaller cantilevers. Embracing diffraction patterns as data yields a potent detection technique that decouples tilt and curvature and simultaneously relaxes the requirements on the illumination alignment and detector position through a measurable which is invariant to translation and rotation. We show analytical results, numerical simulations and physiologically relevant experimental data demonstrating the utility of the diffraction patterns. We offer experimental design guidelines and quantify possible sources of systematic error in OBDT. We demonstrate a new nanometre resolution detection method that can replace OBDT, where diffraction effects from finite sized or patterned cantilevers are exploited. Such effects are readily generalized to cantilever arrays, and allow transmission detection of mechanical curvature, enabling instrumentation with simpler geometry. We highlight the comparative advantages over OBDT by detecting molecular activity of antibiotic Vancomycin. PMID:27255427

  3. Gaussian beam diffraction in inhomogeneous media: solution in frame of complex geometrical optics

    NASA Astrophysics Data System (ADS)

    Kravtsov, Yu. A.; Berczynski, P.

    2005-09-01

    The method of paraxial complex geometrical optics is presented to describe Gaussian beam diffraction in arbitrary smoothly inhomogeneous media, including lens-like media. The method modifies and specifies the results by Babic' (1968), Kirpichnikova (1971), Cerveny, Popov, Psencik (1982), Cerveny (1983, 2001), Timofeev (1995) and Pereverzev (1996) as applied to the optical problems. The method of paraxial complex geometrical optics reduces the problem of Gaussian beam diffraction in inhomogeneous media to the solution of the system of the ordinary differential equations of first order, which can be readily calculated numerically by the Runge-Kutta method. Thereby the paraxial complex geometrical optics radically simplifies description of Gaussian beam diffraction in inhomogeneous media as compared to the numerical methods of wave optics. By the way of example the known analytical solution for Gaussianbeam diffraction both in a free space and in lens-like medium (Bornatici, Maj 2003) are presented. It is pointed out, that the method of paraxial complex geometrical optics turns out to be equivalent to the solutions of the abridged parabolic wave equation.

  4. Super-resolution optical telescopes with local light diffraction shrinkage

    NASA Astrophysics Data System (ADS)

    Wang, Changtao; Tang, Dongliang; Wang, Yanqin; Zhao, Zeyu; Wang, Jiong; Pu, Mingbo; Zhang, Yudong; Yan, Wei; Gao, Ping; Luo, Xiangang

    2015-12-01

    Suffering from giant size of objective lenses and infeasible manipulations of distant targets, telescopes could not seek helps from present super-resolution imaging, such as scanning near-field optical microscopy, perfect lens and stimulated emission depletion microscopy. In this paper, local light diffraction shrinkage associated with optical super-oscillatory phenomenon is proposed for real-time and optically restoring super-resolution imaging information in a telescope system. It is found that fine target features concealed in diffraction-limited optical images of a telescope could be observed in a small local field of view, benefiting from a relayed metasurface-based super-oscillatory imaging optics in which some local Fourier components beyond the cut-off frequency of telescope could be restored. As experimental examples, a minimal resolution to 0.55 of Rayleigh criterion is obtained, and imaging complex targets and large targets by superimposing multiple local fields of views are demonstrated as well. This investigation provides an access for real-time, incoherent and super-resolution telescopes without the manipulation of distant targets. More importantly, it gives counterintuitive evidence to the common knowledge that relayed optics could not deliver more imaging details than objective systems.

  5. Super-resolution optical telescopes with local light diffraction shrinkage.

    PubMed

    Wang, Changtao; Tang, Dongliang; Wang, Yanqin; Zhao, Zeyu; Wang, Jiong; Pu, Mingbo; Zhang, Yudong; Yan, Wei; Gao, Ping; Luo, Xiangang

    2015-01-01

    Suffering from giant size of objective lenses and infeasible manipulations of distant targets, telescopes could not seek helps from present super-resolution imaging, such as scanning near-field optical microscopy, perfect lens and stimulated emission depletion microscopy. In this paper, local light diffraction shrinkage associated with optical super-oscillatory phenomenon is proposed for real-time and optically restoring super-resolution imaging information in a telescope system. It is found that fine target features concealed in diffraction-limited optical images of a telescope could be observed in a small local field of view, benefiting from a relayed metasurface-based super-oscillatory imaging optics in which some local Fourier components beyond the cut-off frequency of telescope could be restored. As experimental examples, a minimal resolution to 0.55 of Rayleigh criterion is obtained, and imaging complex targets and large targets by superimposing multiple local fields of views are demonstrated as well. This investigation provides an access for real-time, incoherent and super-resolution telescopes without the manipulation of distant targets. More importantly, it gives counterintuitive evidence to the common knowledge that relayed optics could not deliver more imaging details than objective systems. PMID:26677820

  6. Super-resolution optical telescopes with local light diffraction shrinkage

    PubMed Central

    Wang, Changtao; Tang, Dongliang; Wang, Yanqin; Zhao, Zeyu; Wang, Jiong; Pu, Mingbo; Zhang, Yudong; Yan, Wei; Gao, Ping; Luo, Xiangang

    2015-01-01

    Suffering from giant size of objective lenses and infeasible manipulations of distant targets, telescopes could not seek helps from present super-resolution imaging, such as scanning near-field optical microscopy, perfect lens and stimulated emission depletion microscopy. In this paper, local light diffraction shrinkage associated with optical super-oscillatory phenomenon is proposed for real-time and optically restoring super-resolution imaging information in a telescope system. It is found that fine target features concealed in diffraction-limited optical images of a telescope could be observed in a small local field of view, benefiting from a relayed metasurface-based super-oscillatory imaging optics in which some local Fourier components beyond the cut-off frequency of telescope could be restored. As experimental examples, a minimal resolution to 0.55 of Rayleigh criterion is obtained, and imaging complex targets and large targets by superimposing multiple local fields of views are demonstrated as well. This investigation provides an access for real-time, incoherent and super-resolution telescopes without the manipulation of distant targets. More importantly, it gives counterintuitive evidence to the common knowledge that relayed optics could not deliver more imaging details than objective systems. PMID:26677820

  7. New approach to imaging spectroscopy using diffractive optics

    NASA Astrophysics Data System (ADS)

    Hinnrichs, Michele; Massie, Mark A.

    1997-10-01

    Over the past several years, Pacific Advanced Technology (PAT) has developed several hyperspectral imagers using diffractive optics as the dispersive media. This new approach has been patented and demonstrated in numerous field tests. PAT has developed hyperspectral cameras in the visible, mid-wave IR and is currently under contrast to the Air Force to develop a dual band hyperspectral lens for simultaneous spectral imaging in both the mid-wave and long- wave IR. The development of these cameras over the years have been sponsored by internal research and development, contracts from the Air Force Phillips Lab., Air Force Wright Labs Armament Division, BMDO and by the Office of Naval Research. Numerous papers have been presented in the past describing the performance of these various hyperspectral cameras. The purpose of this paper is to describe the theory behind the image multi-spectral sensing (IMSS) used in these hyperspectral cameras. IMSS utilizes a very simple optical design that enables a robust and low cost hyper-spectral imaging instrument. The IMSS is a dispersive spectrometer using a single diffractive optical element for both imaging and dispersion. The lens is tuned for a single wavelength giving maximum diffraction efficiency at that wavelength and high efficiency throughout the spectral band-pass of the camera. The diffractive optics disperse the light along the optical axis as opposed to perpendicular to the axis in conventional dispersive spectrometers. A detector array is used as the sensing medium and the spectral images are rad out electronically. POst processing is used to reduce spectral cross talk and to spatially sharpen the spectral images.

  8. Applied optics in the automotive industry.

    PubMed

    Preston, B W

    1969-09-01

    A general discussion of the interrelated subjects of vision, illumination, marking systems, signaling devices, materials, and components as found in the automotive industry is included in this article. Optics as applied in supporting industries, such as the lighting, metal, glass, paint, plastics, and fabrics industries are also discussed. A few examples of optics in these industries as applied to product development and productioncontrol are presented and illustrated. PMID:20072517

  9. Linear systems approach to simulation of optical diffraction.

    PubMed

    Lambert, A J; Fraser, D

    1998-12-01

    The diffractive processes within an optical system can be simulated by computer to compute the diffraction-altered electric-field distribution at the output of the system from the electric-field distribution at the input. In the paraxial approximation the system can be described by an ABCD ray matrix whose elements in turn can be used to simplify the computation such that only a single computational step is required. We describe two rearrangements of such computations that allow the simulation to be expressed in a linear systems formulation, in particular using the fast-Fourier-transform algorithm. We investigate the sampling requirements for the kernel-modifying function or chirp that arises. We also use the special properties of the chirp to determine the spreading imposed by the diffraction. This knowledge can be used to reduce the computation if only a limited region of either the input or the output is of interest. PMID:18301681

  10. On effective and optical resolutions of diffraction data sets.

    PubMed

    Urzhumtseva, Ludmila; Klaholz, Bruno; Urzhumtsev, Alexandre

    2013-10-01

    In macromolecular X-ray crystallography, diffraction data sets are traditionally characterized by the highest resolution dhigh of the reflections that they contain. This measure is sensitive to individual reflections and does not refer to the eventual data incompleteness and anisotropy; it therefore does not describe the data well. A physically relevant and robust measure that provides a universal way to define the `actual' effective resolution deff of a data set is introduced. This measure is based on the accurate calculation of the minimum distance between two immobile point scatterers resolved as separate peaks in the Fourier map calculated with a given set of reflections. This measure is applicable to any data set, whether complete or incomplete. It also allows characterizion of the anisotropy of diffraction data sets in which deff strongly depends on the direction. Describing mathematical objects, the effective resolution deff characterizes the `geometry' of the set of measured reflections and is irrelevant to the diffraction intensities. At the same time, the diffraction intensities reflect the composition of the structure from physical entities: the atoms. The minimum distance for the atoms typical of a given structure is a measure that is different from and complementary to deff; it is also a characteristic that is complementary to conventional measures of the data-set quality. Following the previously introduced terms, this value is called the optical resolution, dopt. The optical resolution as defined here describes the separation of the atomic images in the `ideal' crystallographic Fourier map that would be calculated if the exact phases were known. The effective and optical resolution, as formally introduced in this work, are of general interest, giving a common `ruler' for all kinds of crystallographic diffraction data sets. PMID:24100312

  11. Processing and error compensation of diffractive optical element

    NASA Astrophysics Data System (ADS)

    Zhang, Yunlong; Wang, Zhibin; Zhang, Feng; Qin, Hui; Li, Junqi; Mai, Yuying

    2014-09-01

    Diffractive optical element (DOE) shows high diffraction efficiency and good dispersion performance, which makes the optical system becoming light-weight and more miniature. In this paper, the design, processing, testing, compensation of DOE are discussed, especially the analyzing of compensation technology which based on the analyzing the DOE measurement date from Taylor Hobson PGI 1250. In this method, the relationship between shadowing effect with diamond tool and processing accuracy are analyzed. According to verification processing on the Taylor Hobson NANOFORM 250 lathe, the results indicate that the PV reaches 0.539 micron, the surface roughness reaches 4nm, the step position error is smaller than λ /10 and the step height error is less than 0.23 micron after compensation processing one time.

  12. Image reconstruction algorithms for DOIS: a diffractive optic image spectrometer

    NASA Astrophysics Data System (ADS)

    Lyons, Denise M.; Whitcomb, Kevin J.

    1996-06-01

    The diffractive optic imaging spectrometer, DOIS, is a compact, economical, rugged, programmable, multi-spectral imager. The design implements a conventional CCD camera and emerging diffractive optical element (DOE) technology in an elegant configuration, adding spectroscopy capabilities to current imaging systems (Lyons 1995). This paper reports on the visible prototype DOIS that was designed, fabricated and characterized. Algorithms are presented for simulation and post-detection processing with digital image processing techniques. This improves the spectral resolution by removing unwanted blurred components from the spectral images. DOIS is a practical image spectrometer that can be built to operate at ultraviolet, visible or infrared wavelengths for applications in surveillance, remote sensing, law enforcement, environmental monitoring, laser communications, and laser counter intelligence.

  13. Velocity filtering applied to optical flow calculations

    NASA Technical Reports Server (NTRS)

    Barniv, Yair

    1990-01-01

    Optical flow is a method by which a stream of two-dimensional images obtained from a forward-looking passive sensor is used to map the three-dimensional volume in front of a moving vehicle. Passive ranging via optical flow is applied here to the helicopter obstacle-avoidance problem. Velocity filtering is used as a field-based method to determine range to all pixels in the initial image. The theoretical understanding and performance analysis of velocity filtering as applied to optical flow is expanded and experimental results are presented.

  14. Three-Dimensional Displacement Measurement Using Diffractive Optic Interferometry

    NASA Technical Reports Server (NTRS)

    Gilbert, John A.; Cole, Helen J.; Shepherd, Robert L.; Ashley Paul R.

    1999-01-01

    This paper introduces a powerful new optical method which utilizes diffractive optic interferometry (DOI) to measure both in-plane and out-of-plane displacement with variable sensitivity using the same optical system. Sensitivity is varied by utilizing various combinations of the different wavefronts produced by a conjugate pair of binary Optical elements; a transmission grating is used to produce several illumination beams while a reflective grating replicated on the surface of a specimen, provides the reference for the undeformed state. A derivation of the equations which govern the method is included along with a discussion Of the experimental tests conducted to verify the theory. Overall, the results are excellent, with experimental data agreeing to within a few percent of the theoretical predictions.

  15. Photochromic point-diffraction interferometer for optical testing

    NASA Astrophysics Data System (ADS)

    Quintavalla, Martino; Pariani, Giorgio; Crimi, Giuseppe; Bianco, Andrea; Bertarelli, Chiara

    2012-09-01

    The principles for the realization of rewritable point-diffraction interferometers (PDIs) based on photochromic polyurethane films are described. Pinholes of variable sizes (diameter from 4 to 40 μm) have been optically written onto photochromic substrates converting locally the material from the colored to the uncolored form. The PDIs have been mounted in an interferometric setup and different reflective optics have been tested. By a controlled bleaching of the semi-transparent area around the pinhole, an optimal visibility in the interferograms is reached. Under this conditions several tests of reliability of the interferometer have been carried out.

  16. Cascaded diffractive optical elements for improved multiplane image reconstruction.

    PubMed

    Gülses, A Alkan; Jenkins, B Keith

    2013-05-20

    Computer-generated phase-only diffractive optical elements in a cascaded setup are designed by one deterministic and one stochastic algorithm for multiplane image formation. It is hypothesized that increasing the number of elements as wavefront modulators in the longitudinal dimension would enlarge the available solution space, thus enabling enhanced image reconstruction. Numerical results show that increasing the number of holograms improves quality at the output. Design principles, computational methods, and specific conditions are discussed. PMID:23736247

  17. Teaching diffraction with hands-on optical spectrometry

    NASA Astrophysics Data System (ADS)

    Fischer, Robert

    2012-09-01

    Although the observation of optical spectra is common practice in physics classes, students are usually limited to a passive, qualitative observation of nice colours. This paper discusses a diffraction-based spectrometer that allows students to take quantitative measurements of spectral bands. Students can build it within minutes from generic low-cost materials. The spectrometer’s simple, didactic design allows students to fully comprehend the underlying physical concepts and to engage in a discussion of measurement errors and uncertainties.

  18. Analysis of Contribution from Edge Radiation to Optical Diffraction Radiation

    SciTech Connect

    C. Liu, P. Evtushenko, A. Freyberger, C. Liu, A.H. Lumpkin

    2009-05-01

    Beam size measurement with near-field optical diffraction radiation (ODR) has been carried out successfully at CEBAF. The ODR station is installed on the Hall-A beam line after eight bending magnets. The ODR images were affected by an unexpected radiation. Some calculations for analyzing the source of the radiation will be presented. Furthermore, two schemes will be proposed to alleviate the contamination.

  19. Simultaneous multicolor image formation with a single diffractive optical element.

    PubMed

    Levy, U; Marom, E; Mendlovic, D

    2001-08-01

    A design for a novel diffractive optical element (DOE) that can reconstruct three different intensity patterns when it is illuminated by three different wavelengths is presented. If the chosen wavelengths are red, green, and blue, full-color reconstruction capability is obtained. Reconstruction is achieved in the near field (Fresnel domain). Computer simulation results as well as experimental evidence are presented, proving the capabilities of this novel DOE design procedure. PMID:18049545

  20. Applied possibilities for x-ray diffraction interferometry

    NASA Astrophysics Data System (ADS)

    Raransky, M. D.; Struk, J. M.; Fodchuk, Igor M.; Shafraniuk, V. P.; Raransky, A. M.

    1995-11-01

    Among existing x ray diffraction diagnostics nonperfections of crystals the specific location take methods are based on use of x-ray dynamic diffraction effects. From them the most sensitive are based on interferention. The Pendellosung and Moire fringes methods arise in consequence of coherent dynamic interaction of wave fields in single crystals. One of the main advantages of the Moire method is the extraordinary high sensitivity to insignificant deformations of crystal lattice ((Delta) d/d approximately 10-8) and atomic planes turns ((delta) approximately 0.01'). Created by a method of x-ray diffraction Moire the unique phase magnification permits us to directly observe the nuclear rows of crystal lattice. Until recently the attention of researchers attracted, basically, precise measurements of refraction parameters and dispersion amendments to nuclear scattering amplitudes, measurement of movy with large accuracy and refinement of Avogadro number, and the creation of new multi crystal interferometers. At the same time, little opportunities of x-ray interferometry at research of crystal structure defects were used. For the first time the opportunity of definition by method x-ray diffraction Moire of Burgers vectors of individual dislocation was demonstrated by M. Hart, Christiansen has studied the series of 60 degree(s) dislocation in Si on Moire images. Tensions in Si, caused by Ar ions implantation, were defined in the work. The purpose, which the authors of given reviews pursue consists in demonstration of new opportunities of x-ray three crystal interferometry in the investigation of single and complex defects.

  1. Optical properties of X-rays--dynamical diffraction.

    PubMed

    Authier, André

    2012-01-01

    The first attempts at measuring the optical properties of X-rays such as refraction, reflection and diffraction are described. The main ideas forming the basis of Ewald's thesis in 1912 are then summarized. The first extension of Ewald's thesis to the X-ray case is the introduction of the reciprocal lattice. In the next step, the principles of the three versions of the dynamical theory of diffraction, by Darwin, Ewald and Laue, are given. It is shown how the comparison of the dynamical and geometrical theories of diffraction led Darwin to propose his extinction theory. The main optical properties of X-ray wavefields at the Bragg incidence are then reviewed: Pendellösung, shift of the Bragg peak, fine structure of Kossel lines, standing waves, anomalous absorption, paths of wavefields inside the crystal, Borrmann fan and double refraction. Lastly, some of the modern applications of the dynamical theory are briefly outlined: X-ray topography, location of adsorbed atoms at crystal surfaces, optical devices for synchrotron radiation and X-ray interferometry. PMID:22186282

  2. Sub-diffraction-limited optical imaging with superlens and hyperlens

    NASA Astrophysics Data System (ADS)

    Lee, Hyesog

    Optical microscopy has been the most widely used imaging tool in various research disciplines for the last century. However, it has fundamental resolution limit called the Diffraction Limit, which prevents it from observing objects smaller than half of the wavelength. This is caused by the inability of lenses, which are located at far field of the objects, to detect high spatial frequency information encoded in evanescent waves which decay away in the near field. Along with modern technological advancements especially in the field of nanotechnology, numerous innovative ideas sprung up in the past several decades in efforts to break the diffraction barrier and achieve nano-scale optical imaging. The most popular method up to date uses near-field scanning scheme which tends to be very slow and impractical for real-time imaging. Other methods require rather complex imaging optics and multiple measurements of the same sample. So far, true far-field and real-time sub-diffraction-limited optical imaging method is yet to be developed. Here I report new imaging schemes, Superlensing (Near and Far-field superlens) and Hyperlensing, which are capable of not only imaging beyond the Diffraction Limit in resolution but making real-time imaging possible. The Superlens enhances evanescent waves through surface plasmon (SP) resonance. The Far-field Superlens (FSL) scatters them into the far-field and the detected information is then used to numerically reconstruct high resolution image. Hyperlens concept utilizes unusual electromagnetic properties of metamaterials to deliver high spatial frequency information directly into the far-field. It magnifies nano-scale objects just enough for optical microscope to image and no post-imaging process is needed. In this dissertation, detailed experiment designs including nano-fabrication of the superlens and the hyperlens structures were proposed and the first ever imaging results were presented. The resolving power beyond the Diffraction

  3. Advanced simulations of optical transition and diffraction radiation

    NASA Astrophysics Data System (ADS)

    Aumeyr, T.; Billing, M. G.; Bobb, L. M.; Bolzon, B.; Bravin, E.; Karataev, P.; Kruchinin, K.; Lefevre, T.; Mazzoni, S.

    2015-04-01

    Charged particle beam diagnostics is a key task in modern and future accelerator installations. The diagnostic tools are practically the "eyes" of the operators. The precision and resolution of the diagnostic equipment are crucial to define the performance of the accelerator. Transition and diffraction radiation (TR and DR) are widely used for electron beam parameter monitoring. However, the precision and resolution of those devices are determined by how well the production, transport and detection of these radiation types are understood. This paper reports on simulations of TR and DR spatial-spectral characteristics using the physical optics propagation (POP) mode of the Zemax advanced optics simulation software. A good consistency with theory is demonstrated. Also, realistic optical system alignment issues are discussed.

  4. LINC-NIRVANA: cryogenic optics for diffraction limited beam combination

    NASA Astrophysics Data System (ADS)

    Bizenberger, Peter; Baumeister, Harald; Herbst, Tom; Zhang, Xianyu

    2012-09-01

    LINC-NIRVANA is an interferometric imaging camera, which combines the two 8.4 m telescopes of the Large Binocular Telescope (LBT). The instrument operates in the wavelength range from 1.1 μm to 2.4 μm, covering the J, H and K-band, respectively. The beam combining camera (NIRCS) offers the possibility to achieve diffraction limited images with the special resolution of a 23 m telescope. The optics are designed to deliver a 10 arcsec × 10 arcsec field of view with 5 mas resolution. In this paper we describe the evolution of the cryogenic optics, from design and manufacturing to verification. Including the argumentation for decisions we made in order to present a sort of guideline for large cryo-optics. We also present the alignment and testing strategies at a detailed level.

  5. Dedicated spectrometers based on diffractive optics: design, modelling and evaluation

    NASA Astrophysics Data System (ADS)

    Løvhaugen, O.; Johansen, I.-R.; Bakke, K. A. H.; Fismen, B. G.; Nicolas, S.

    The described design of diffractive optical elements for low cost IR-spectrometers gives a built-in wavelength reference and allows 'spectral arithmetic' to be implemented in the optical performance of the DOE. The diffractive element combines the function of the lenses and the grating and eliminates the need for alignment of those components in the standard scanned grating spectrometer design. The element gives out a set of foci, each with one spectral component, which are scanned across a detector, thus relaxing the demands for scan angle control. It can thus be regarded as an alternative solution to a beam splitter and band pass filter instrument. Software tools have been designed to ease the adaptation of the design to different applications. To model the performance of the spectrometers we have implemented a scalar Rayleigh-Sommerfeldt diffraction model. The gold-coated elements are produced by injection moulding using a compact disc (CD) moulding technique and mould inlays mastered by e-beam lithography. The optimized selection of wavelength bands and the classification of the measured signal use a combination of principal component analysis and robust statistical methods. Typical applications will be material characterization of recycled plastics and gas monitoring. Spectrometers for two different applications have been built and tested. Comparisons between the design goals and the measured performance have been made and show good agreements.

  6. LINC-NIRVANA: Diffraction limited optics in cryogenic environment

    NASA Astrophysics Data System (ADS)

    Bizenberger, Peter; Baumeister, Harald; Fopp, Patrick; Herbst, Tom; Laun, Werner; Mohr, Lars; Moreno-Ventas, Javier

    2014-07-01

    LINC-NIRVANA is an instrument combining the two 8.4 m telescopes of the Large Binocular Telescope (LBT) coherently, in order to achieve the optical resolution of the 23 meter baseline. For this interferometric instrument concept, the common beam combination requires diffraction limited optical performance. The optics, realized as a Cassegrain telescope design, consists of aluminum mirrors, designed and manufactured to fulfill the challenging specifications required for interferometric imaging. Due to the science wavelength range from 1 μm to 2.4 μm, covering the J, H and K band of the atmosphere, the complete beam combiner including the optics is operated in cryogenic environment at 60 Kelvin. Here, we demonstrate the verification of the optical performance at this temperature for classical in-coherent and coherent illumination. We outline the test setup and present the achieved results of wavefront error for the individual beams and fringe contrast for the interferometric point spread function. This paper continues the already presented integration of the interferometric camera with the focus on the performance of the cryogenic optics.

  7. Diffraction tomography applied to simulated ultrasound through breast tissue

    NASA Astrophysics Data System (ADS)

    Chambers, David H.

    2002-11-01

    Diffraction tomography is used to obtain images of sound speed and attenuation of a slice of breast tissue obtained from the Visible Woman data set. Simulated ultrasound data was generated using an acoustic propagation code run on the ASCI Blue Pacific computer at Lawrence Livermore National Laboratory. Data was generated for a slice of healthy tissue, and a slice with simulated lesions to determine the ability of the imaging method to detect various abnormalities in the breast. In addition, the time reversal operator for the slice was constructed from the data and the eigenfunctions backpropagated into the slice as first suggested by Mast [Mast, Nachman, and Waag, J. Acoust. Soc. Am. 102(2)] to identify structures associated with each time reversal mode for both the healthy tissue and tissue with lesions.

  8. High throughput optoelectronic smart pixel systems using diffractive optics

    NASA Astrophysics Data System (ADS)

    Chen, Chih-Hao

    1999-12-01

    algorithm to design Diffractive Optical Elements (DOEs) having higher uniformity and better signal-to-noise ratio. The algorithm is based on nonlinear least-square optimization procedures and phase-shifting quantization scheme to minimize the reconstruction error of DOEs. We also describe a modified diffractive microlens design algorithm to overcome linewidth limitations in fabrication while achieving higher numerical aperture and better power efficiency. Several diffractive optical devices used in our smart pixel systems, including microlens arrays and spot array generators, are designed by these algorithms, and have been fabricated and characterized for system integration.

  9. Light coupling into an optical microcantilever by an embedded diffraction grating.

    PubMed

    Zinoviev, K; Dominguez, C; Plaza, J A; Cadarso, V; Lechuga, L M

    2006-01-10

    By measuring the excitation efficiency of an optical waveguide on a diffraction grating one can accurately register the changes in the incidence angle of the exciting light beam. This phenomenon was applied to detect ultrasmall deflections of silicon dioxide cantilevers of submicrometer thickness that were fabricated with corrugation on top to act as diffraction grating couplers. The power of light coupled into the cantilevers was monitored with a conventional photodetector and modulated using mechanical vibration of the cantilever, thus changing the spatial orientation of the coupler with respect to the incident light beam. The technique can be considered as an alternative to the methods known for detection of cantilever deflection. PMID:16422154

  10. Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction.

    PubMed

    Maddox, B R; Akin, M C; Teruya, A; Hunt, D; Hahn, D; Cradick, J; Morgan, D V

    2016-08-01

    Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from the sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10(7) molybdenum Kα photons. PMID:27587130

  11. Numerical study of grating-assisted optical diffraction tomography

    SciTech Connect

    Chaumet, Patrick C.; Belkebir, Kamal; Sentenac, Anne

    2007-07-15

    We study the resolution of an optical diffraction tomography system in which the objects are either in an homogeneous background or deposited onto a glass prism, a prism surmounted by a thin metallic film or a prism surmounted by a metallic film covered by a periodically nanostructured dielectric layer. For all these configurations, we present an inversion procedure that yields the map of the relative permittivity of the objects from their diffracted far field. When multiple scattering can be neglected, we show that the homogeneous, prism, and metallic film configurations yield a resolution about {lambda}/4 while the grating substrate yields a resolution better than {lambda}/10. When Born approximation fails, we point out that it is possible to neglect the coupling between the object and the substrate and account solely for the multiple scattering within the objects to obtain a satisfactory reconstruction. Last, we present the robustness of our inversion procedure to noise.

  12. The diffraction limit of an optical spectrum analyzer

    NASA Astrophysics Data System (ADS)

    Kolobrodov, V. G.; Tymchik, G. S.; Kolobrodov, M. S.

    2015-11-01

    This article examines a systematic error that occurs in optical spectrum analyzers and is caused by Fresnel approximation. The aim of the article is to determine acceptable errors of spatial frequency measurement in signal spectrum. The systematic error of spatial frequency measurement has been investigated on the basis of a physical and mathematical model of a coherent spectrum analyzer. It occurs as a result of the transition from light propagation in free space to Fresnel diffraction. Equations used to calculate absolute and relative measurement errors depending on a diffraction angle have been obtained. It allows us to determine the limits of the spectral range according to the given relative error of the spatial frequency measurement.

  13. The application of diffractive optical elements in the optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Egorov, D. I.; Tsyganok, E. A.

    2016-04-01

    The article investigates the possibility of using diffractive optical elements on an example of the kinoform in the optical coherence tomography (OCT). The article gives a brief overview of modern methods of research in the OCT, the expediency of development hyperchromatic lenses for spectral OCT systems. The authors made the aberration analysis of diffractive optical element (DOE), conducted a review of its application, and the DOE proposed to use in the example of a kinoform as the main force component of the hyperchromatic lens. In conclusion, the article provides examples of developed hybrid lenses for two spectral ranges, lens transmittance analysis and the assessment of their adaptability.

  14. Optical diffraction tomography: accuracy of an off-axis reconstruction

    NASA Astrophysics Data System (ADS)

    Kostencka, Julianna; Kozacki, Tomasz

    2014-05-01

    Optical diffraction tomography is an increasingly popular method that allows for reconstruction of three-dimensional refractive index distribution of semi-transparent samples using multiple measurements of an optical field transmitted through the sample for various illumination directions. The process of assembly of the angular measurements is usually performed with one of two methods: filtered backprojection (FBPJ) or filtered backpropagation (FBPP) tomographic reconstruction algorithm. The former approach, although conceptually very simple, provides an accurate reconstruction for the object regions located close to the plane of focus. However, since FBPJ ignores diffraction, its use for spatially extended structures is arguable. According to the theory of scattering, more precise restoration of a 3D structure shall be achieved with the FBPP algorithm, which unlike the former approach incorporates diffraction. It is believed that with this method one is allowed to obtain a high accuracy reconstruction in a large measurement volume exceeding depth of focus of an imaging system. However, some studies have suggested that a considerable improvement of the FBPP results can be achieved with prior propagation of the transmitted fields back to the centre of the object. This, supposedly, enables reduction of errors due to approximated diffraction formulas used in FBPP. In our view this finding casts doubt on quality of the FBPP reconstruction in the regions far from the rotation axis. The objective of this paper is to investigate limitation of the FBPP algorithm in terms of an off-axis reconstruction and compare its performance with the FBPJ approach. Moreover, in this work we propose some modifications to the FBPP algorithm that allow for more precise restoration of a sample structure in off-axis locations. The research is based on extensive numerical simulations supported with wave-propagation method.

  15. All-optical switching of diffraction gratings infiltrated with dye-doped liquid crystals

    NASA Astrophysics Data System (ADS)

    Lucchetta, D. E.; Vita, F.; Simoni, F.

    2010-12-01

    We report the realization and the characterization of an all-optical switching device based on a transmission grating recorded in a polymeric substrate infiltrated with a methyl red-doped liquid crystal. The properties of this highly nonlinear mixture are exploited to modulate the diffraction of the grating by a pump beam when a static electric field is applied. The behavior of the device is in agreement with the existing model for methyl red-doped liquid crystals.

  16. Technology Development of Stratified Volume Diffractive Optics for Waveguide Coupling

    NASA Technical Reports Server (NTRS)

    Chambers, Diana M.

    2000-01-01

    Stratified Volume Diffractive Optical Elements (SVDOE) appear to be viable as high-efficiency waveguide couplers. Preliminary design studies were conducted under this task to provide initial device parameters for evaluation. However, these designs should be revisited prior to fabrication of a device for testing. The emphasis of this task has been development and implementation of fabrication procedures necessary for SVDOE'S, namely alignment of grating layers, Including offsets, to within required tolerances. Progress in this area Indicates that the alignment technique chosen is viable and tolerances have been reached that allow reasonable performance ranges. Approaches have been identified to improve alignment tolerances even further.

  17. Optical fiber alignment using cleaved-edge diffracted light

    NASA Astrophysics Data System (ADS)

    Brun, Louis C.; Bergeron, Patrick; Duguay, Michel A.; Ouellette, Francois; Tetu, Michel

    1993-08-01

    We describe a simple technique for aligning optical fibers prior to fusion splicing. The technique relies on the fact that well-cleaved fiber ends have extremely sharp edges. By making the narrow pencil of light emerging from one fiber scan laterally over the entrance face of a second fiber, and by monitoring the light diffracted past its sharp edges, we can locate precisely the geometric center of the output fiber. With this technique, we have aligned fiber cores with a mean lateral offset of 0.81 micrometers , the major part of this offset caused by the eccentricity of the core relative to the cladding's circular perimeter.

  18. Aplanatic grazing incidence diffraction grating: a new optical element

    SciTech Connect

    Hettrick, M.C.

    1986-09-15

    We present the theory of a grazing incidence reflection grating capable of imaging at submicron resolution. The optic is mechanically ruled on a spherical or cylindrical surface with varied groove spacings, delivering diffraction-limited response and a wide field of view at a selected wavelength. Geometrical aberrations are calculated on the basis of Fermat's principle, revealing significant improvements over a grazing incidence mirror. Aplanatic and quasi-aplanatic versions of the grating have applications in both imaging and scanning microscopes, microprobes, collimators, and telescopes. A 2-D crossed system of such gratings, similar to the grazing incidence mirror geometry of Kirkpatrick and Baez, could potentially provide spatial resolutions of --200 A.

  19. Multilevel micro-structuring of glassy carbon for precision glass molding of diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Prater, Karin; Dukwen, Julia; Scharf, Toralf; Herzig, Hans Peter; Plöger, Sven; Hermerschmidt, Andreas

    2015-03-01

    A consumer market for diffractive optical elements in glass can only be created if high efficient elements are available at affordable prices. In diffractive optics the efficiency and optical properties increases with the number of levels used, but in the same way the costs are multiplied by the number if fabrication steps. Replication of multilevel diffractive optical elements in glass would allow cost efficient fabrication but a suitable mold material is needed. Glassy carbon shows a high mechanical strength, thermal stability and non-sticking adhesion properties, which makes it an excellent candidate as mold material for precision compression molding of low and high glass-transition temperature materials. We introduce an 8 level micro structuring process for glassy carbon molds with standard photolithography and a Ti layer as hard mask for reactive ion etching. The molds were applied to thermal imprinting onto low and high transition temperature glass. Optical performance was tested for the molded samples with different designs for laser beamsplitters. The results show a good agreement to the design specification. Our result allow us to show limitations of our fabrication technique and we discussed the suitability of precision glass molding for cost efficient mass production with a high quality.

  20. Diffractive optics with high Bragg selectivity: volume holographic optical elements in Bayfol® HX photopolymer film

    NASA Astrophysics Data System (ADS)

    Bruder, Friedrich-Karl; Fäcke, Thomas; Hagen, Rainer; Hönel, Dennis; Orselli, Enrico; Rewitz, Christian; Rölle, Thomas; Walze, Günther

    2015-09-01

    For a long time volume Holographic Optical Elements (vHOE) have been discussed as an alternative, but were hampered by a lack of suitable materials. They provide several benefits over surface corrugated diffractive optical element like high diffraction efficiency due to their ability to reconstruct a single diffraction order, freedom of optical design by freely setting the replay angles and adjusting their bandwidth by a selection of the vHOE's thickness. Additional interesting features are related to their high Bragg selectivity providing transparent films for off-Bragg illumination. In this paper we report on our newly developed photopolymer film technology (Bayfol® HX) that uniquely requires no post processing after holographic exposure. We explain the governing non-local polymerization driven diffusion process leading to an active mass transport triggered by constructive interference. Key aspects of the recording process and their impact on index modulation formation is discussed. The influence on photopolymer film thickness on the bandwidth is shown. A comparison between coupled wave theory (CWT) simulation and experimental results is given. There are two basic recording geometries: reflection and transmission vHOEs. We explain consequences of how to record them properly and discuss in more detail the special challenges in transmission hologram recording. Here beam ratio and customization of photopolymer film properties can be applied most beneficially to achieve highest diffraction efficiency.

  1. Superresolution technology applied to optical discs

    NASA Astrophysics Data System (ADS)

    Zhou, Changhe; Luo, Hongxin

    2005-09-01

    Smaller focal points are essential for the development of the next-generation optical disc. The size of focal point depends on the diffraction effect that is dependant on the numerical aperture of a lens and the wavelength of light. However, increase of the numerical aperture and decrease of the light wavelength will be ultimately limited due to the technical difficulty of fabricating a too-high NA lens and the too-short wavelength laser. In this paper, we report another approach of using the superresolution technology to compress the size of the so-called Airy spot for the next-generation optical disc, which is independent on the wavelength of laser. The superresolution phase plates are designed and fabricated with a microoptics technique. When such a phase plate is inserted into the optical system, the central spot at the focal plane of a lens is decreased to be 0.8 times of the Airy pattern, implying the possibility of reading higher storage density of optical discs. The most attractive feature is that the phase plate can be mass-produced at a very low cost, compared with the high cost of the high-numerical lens and/or the short wavelength laser. The disadvantages are that the inserted phase plate will induce the slight circular sidelobes around the central sport, so that it consumes a little more laser energy. The shortcoming could be overcome with suitable amendment. We have fabricated the phase plates with the surface-relief profile on a normal glass for phase modulation. Experimental results of superresolution effect with a low numerical aperture (NA=0.1) and a high-numerical lens (NA=0.8) are reported, which are in good agreement with the theoretical prediction. Superresolution technique should be highly interesting as a novel technique of the next-generation pickup head for reading the high storage of the optical discs.

  2. Theory of optical ellipsometric measurements from muscle diffraction studies.

    PubMed Central

    Yeh, Y; Baskin, R J

    1988-01-01

    A theory of optical ellipsometry describing the complete phase shift and ellipticity of light diffracted from a single muscle fiber is developed. We show that both the phase shift information, described commonly by the birefringence of the fiber, and the ellipticity information, described by the differential polarizability ratio, are necessary to provide a complete picture of the complex contributions to the total optical anisotropy spectra from a diffraction pattern derived from the striated muscle cell. Both form and intrinsic contributions play significant roles in either the birefringence measurement or the differential field ratio measurement. However, we show that their relative weights in these two measured quantities are different, and measuring both of these parameters is necessary to obtain a more complete assessment of the cross-bridge structure and dynamics. The theoretical results have been tested for three different situations: solvent index matching, passive stretch of a resting fiber, and cross-bridge changes under isometric conditions. Comparisons between experimental data and simple model calculations provide much information regarding cross-bridge orientation and structure. PMID:3207822

  3. Microbial Diffraction Gratings as Optical Detectors for Heavy Metal Pollutants

    NASA Technical Reports Server (NTRS)

    Noever, David; Matsos, Helen; Brittain, Andrew; Obenhuber, Don; Cronise, Raymond; Armstrong, Shannon

    1996-01-01

    As a significant industrial pollutant, cadmium is implicated as the cause of itai-itai disease. For biological detection of cadmium toxicity, an assay device has been developed using the motile response of the protozoa species, Tetrahymena pyriformis. This mobile protozoa measures 50 microns in diameter, swims at 10 body lengths per second, and aggregates into macroscopically visible patterns at high organism concentrations. The assay demonstrates a Cd(+2) sensitivity better than 1 micro-M and a toxicity threshold to 5 micro-M, thus encouraging the study of these microbial cultures as viable pollution detectors. Using two-dimensional diffraction patterns within a Tetrahymena culture, the scattered light intensity varies with different organism densities (population counts). The resulting density profile correlates strongly with the toxic effects at very low dosages for cadmium (less than 5 ppm) and then for poison protection directly (with nickel and copper antagonists competing with cadmium absorption). In particular, copper dosages as low as 0.1-0.5 mM Cu have shown protective antagonism against cadmium, have enhanced density variability for cultures containing 1 mM Cd(+2) and therefore have demonstrated the sensitivity of the optical detection system. In this way, such microbial diffraction patterns give a responsive optical measure of biological culture changes and toxicity determination in aqueous samples of heavy metals and industrial pollutants.

  4. Generalized optical ABCD theorem and its application to the diffraction integral calculation.

    PubMed

    Zhao, Chaoying; Tan, Weihan; Guo, Qizhi

    2004-11-01

    We generalize the transfer matrix ABCD theorem for paraxial rays of the optical system to skew rays propagated off axis, whether or not the system possesses rotational symmetry. Furthermore, we apply the generalized ABCD theorem to evaluate the diffraction integral matrix elements A-D expressed in terms of the angle eikonal T, with the primary aberrations included. Finally, analysis and numerical calculation are given for propagation of a light beam through the optical system in the case in which spherical aberration and coma are present. PMID:15535373

  5. Wavelength-division multiplexed optical integrated circuit with vertical diffraction grating

    NASA Technical Reports Server (NTRS)

    Lang, Robert J. (Inventor); Forouhar, Siamak (Inventor)

    1994-01-01

    A semiconductor optical integrated circuit for wave division multiplexing has a semiconductor waveguide layer, a succession of diffraction grating points in the waveguide layer along a predetermined diffraction grating contour, a semiconductor diode array in the waveguide layer having plural optical ports facing the succession of diffraction grating points along a first direction, respective semiconductor diodes in the array corresponding to respective ones of a predetermined succession of wavelengths, an optical fiber having one end thereof terminated at the waveguide layer, the one end of the optical fiber facing the succession of diffraction grating points along a second direction, wherein the diffraction grating points are spatially distributed along the predetermined contour in such a manner that the succession of diffraction grating points diffracts light of respective ones of the succession of wavelengths between the one end of the optical fiber and corresponding ones of the optical ports.

  6. Large Diffractive Optics for GEo-Based Earth Surveillance

    SciTech Connect

    Hyde, R A

    2003-09-11

    in diameter, building ten-fold larger ones for GEO applications (let alone delivering and operating them there) presents major difficulties. However, since the challenges of fielding large platforms in GEO are matched by the benefits of continuous coverage, we propose a program to develop such optical platforms. In this section, we will examine a particular form of large aperture optic, using a flat diffractive lens instead of the more conventional curved reflectors considered elsewhere in this report. We will discuss both the development of this type of large aperture optics, as well as the steps necessary to use it for GEO-based Earth surveillance. In a later section of this report we will discuss another use for large diffractive optics, their application for global-reach laser weapons.

  7. Optical color-image encryption in the diffractive-imaging scheme

    NASA Astrophysics Data System (ADS)

    Qin, Yi; Wang, Zhipeng; Pan, Qunna; Gong, Qiong

    2016-02-01

    By introducing the theta modulation technique into the diffractive-imaging-based optical scheme, we propose a novel approach for color image encryption. For encryption, a color image is divided into three channels, i.e., red, green and blue, and thereafter these components are appended by redundant data before being sent to the encryption scheme. The carefully designed optical setup, which comprises of three 4f optical architectures and a diffractive-imaging-based optical scheme, could encode the three plaintexts into a single noise-like intensity pattern. For the decryption, an iterative phase retrieval algorithm, together with a filter operation, is applied to extract the primary color images from the diffraction intensity map. Compared with previous methods, our proposal has successfully encrypted a color rather than grayscale image into a single intensity pattern, as a result of which the capacity and practicability have been remarkably enhanced. In addition, the performance and the security of it are also investigated. The validity as well as feasibility of the proposed method is supported by numerical simulations.

  8. Spin-to-orbit conversion at acousto-optic diffraction of light: conservation of optical angular momentum.

    PubMed

    Skab, Ihor; Vlokh, Rostyslav

    2012-04-01

    Acousto-optic diffraction of light in optically active cubic crystals is analyzed from the viewpoint of conservation of optical angular momentum. It is shown that the availability of angular momentum in the diffracted optical beam can be necessarily inferred from the requirements of angular momentum conservation law. As follows from our analysis, a circularly polarized diffracted wave should bear an orbital angular momentum. The efficiency of the spin-to-orbit momentum conversion is governed by the efficiency of acousto-optic diffraction. PMID:22505104

  9. Applications of optical holography to applied mechanics.

    NASA Technical Reports Server (NTRS)

    Aprahamian, R.

    1972-01-01

    This paper provides a brief summary of applications of optical holography and holographic interferometry to applied solid mechanics. Basic equations commonly used in fringe interpretation are described and used to reduce the data contained on holographic interferograms. A comparison of data obtained holographically with analytical prediction is given wherever possible. Applications contained herein include front surface physics, study of bomb breakup, transverse wave propagation, study of mode shapes of panels at elevated temperatures, nondestructive testing, and vibration analysis.

  10. Diffractive optical elements for generating arbitrary line foci

    NASA Technical Reports Server (NTRS)

    Mait, Joseph N.; Prather, Dennis W.; Vandergracht, Joseph; Tayag, Tristan J.

    1993-01-01

    The key optical component in the architecture of the linearly variable magnification telescope presented here is a conical lens. This architecture has application to Doppler radar processing and to wavelet processing. Unfortunately, the unique surface profile of a conical lens does not allow traditional grinding techniques to be used for fabrication; therefore, its fabrication is considered custom. In addition to the requirement of custom fabrication, a refractive conical lens introduces phase aberrations that are intrinsic to its conic shape. Further, due to the large prismatic component of the lens, the variable magnification telescope architecture is off-axis. To overcome the fabrication and application difficulties of a refractive lens, we consider the construction of a hybrid diffractive-refractive lens.

  11. Investigation of diffractive optical element femtosecond laser machining

    NASA Astrophysics Data System (ADS)

    Chabrol, Grégoire R.; Ciceron, Adline; Twardowski, Patrice; Pfeiffer, Pierre; Flury, Manuel; Mermet, Frédéric; Lecler, Sylvain

    2016-06-01

    This paper presents an explorative study on the machining of diffractive optical elements (DOEs) in transparent materials using a femtosecond laser source. A simple form of DOE, a binary phase grating with a period of 20.85 μm (σ = 0.5 μm), a groove depth and width of 0.7 μm (σ = 0.2 μm) and 8.8 μm (σ = 0.5 μm) respectively, was successfully machined in BK7. The topographic characteristics were measured by white light interferometry and scanning electron microscopy (SEM). The processing was carried out on high precision stages with an ultrafast fibre laser (350 fs) emitting a 343 nm pulse focused onto the sample with a stationary microscope objective. A diffracted efficiency of 27%, obtained with a spectro goniometer, was corroborated by the theoretical results obtained by the Fourier modal method (FMM), taking into account the measured topographic values. These encouraging results demonstrate that high-speed femtosecond laser manufacturing of DOE in bulk glasses can be achieved, opening the way to rapid prototyping of multi-layered-DOEs.

  12. Miniaturization of an interferometric distance sensor employing diffractive optics

    NASA Astrophysics Data System (ADS)

    Koukourakis, Nektarios; Kuschmierz, Robert; Bohling, Michael; Jahns, Jürgen; Fischer, Andreas; Czarske, Jürgen W.

    2014-08-01

    In order to improve safety, lifetime and energy efficiency of turbo machines, the behavior of the turbine blades has to be monitored during operation. This is a great challenge for metrology, since small, robust and non-contact position measurement techniques are required that offer both micrometer accuracy and microsecond temporal resolution. The Laser-Doppler-Distance (LDD) -Sensor proved to be an adequate technique to perform such measurements. However, the usage in turbo machines requires a miniaturized and temperature-stable sensor-head. In this paper we introduce a miniaturized design of the LDD-sensor that is based on common-path detection. First results indicated that the numerical aperture of the common-path detection is small in comparison to former implementations that used separate paths for illumination and detection. We find that decreasing the numerical aperture strongly increases the systematic measurement uncertainty. For this purpose a novel diffractive optical element containing a diffracting-lens was designed and used to increase the numerical aperture of the common-path detection without affecting the sensor size. Experiments prove that the new element reduces the relative systematic measurement uncertainty by a factor of ten. The mean systematic position measurement uncertainty amounts to Δzmean≈16 μm. The resulting sensor has dimensions of 25×25×60 mm3, offers temperature-stability and achieves micrometer resolution.

  13. Improvement of the signal integrity in diffractive optical encoders

    NASA Astrophysics Data System (ADS)

    Kress, Bernard; Mueller, Ulrich

    2014-09-01

    We are presenting several techniques to improve the quality of the signals in diffractive optics encoders, for either linear and rotational encoders. We have developed previously various hybrid incremental/absolute disk based rotary diffractive encoders architectures. While the binary signals for absolute encoding were usually of sufficiently good quality to retrieve the entire Gray code signal over the desired resolutions (10, 12 or 14 bits), the quality and integrity of the sinusoidal signals for the incremental part of the encoder needed to be improved, since these are the signals allowing the encoder to go to much higher interpolated resolutions (20 bits or over). A good precision over the interpolated signals assumes very accurate sinusoidal profiles form the raw signals. Strong interpolation can only be done on high quality sinusoidal native signals (also referred to as pulses per revolution or PPR). A typical high resolution incremental encoder might provide 12 to 16 native sinusoidal PPRs, but the interpolation over these signals can reach way over 20 bits of resolution if the signals are of good quality.

  14. Diffractive and geometric optical systems characterization with the Fresnel Gaussian shape invariant.

    PubMed

    Cywiak, Moisés; Servín, Manuel; Morales, Arquímedes

    2011-01-31

    Full characterization of optical systems, diffractive and geometric, is possible by using the Fresnel Gaussian Shape Invariant (FGSI) previously reported in the literature. The complex amplitude distribution in the object plane is represented by a linear superposition of complex Gaussians wavelets and then propagated through the optical system by means of the referred Gaussian invariant. This allows ray tracing through the optical system and at the same time allows calculating with high precision the complex wave-amplitude distribution at any plane of observation. This method is similar to conventional ray tracing additionally preserving the undulatory behavior of the field distribution. That is, we are propagating a linear combination of Gaussian shaped wavelets; keeping always track of both, the ray trajectory, and the wave phase of the whole complex optical field. This technique can be applied in a wide spectral range where the Fresnel diffraction integral applies including visible, X-rays, acoustic waves, etc. We describe the technique and we include one-dimensional illustrative examples. PMID:21369004

  15. Diffractive optical variable image devices generated by maskless interferometric lithography for optical security

    NASA Astrophysics Data System (ADS)

    Cabral, Alexandre; Rebordão, José M.

    2011-05-01

    In optical security (protection against forgery and counterfeit of products and documents) the problem is not exact reproduction but the production of something sufficiently similar to the original. Currently, Diffractive Optically Variable Image Devices (DOVID), that create dynamic chromatic effects which may be easily recognized but are difficult to reproduce, are often used to protect important products and documents. Well known examples of DOVID for security are 3D or 2D/3D holograms in identity documents and credit cards. Others are composed of shapes with different types of microstructures yielding by diffraction to chromatic dynamic effects. A maskless interferometric lithography technique to generate DOVIDs for optical security is presented and compared to traditional techniques. The approach can be considered as a self-masking focused holography on planes tilted with respect to the reference optical axes of the system, and is based on the Scheimpflug and Hinge rules. No physical masks are needed to ensure optimum exposure of the photosensitive film. The system built to demonstrate the technique relies on the digital mirrors device MOEMS technology from Texas Instruments' Digital Light Processing. The technique is linear on the number of specified colors and does not depend either on the area of the device or the number of pixels, factors that drive the complexity of dot-matrix based systems. The results confirmed the technique innovation and capabilities in the creation of diffractive optical elements for security against counterfeiting and forgery.

  16. Diffraction patterns and nonlinear optical properties of gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Majles Ara, M. H.; Dehghani, Z.; Sahraei, R.; Daneshfar, A.; Javadi, Z.; Divsar, F.

    2012-03-01

    Stable gold nanoparticles have been prepared by using soluble starch as both the reducing and stabilizing agents; this reaction was carried out at 40 °C for 5 h. The obtained gold nanoparticles were characterized by UV-Vis absorption spectroscopy, transmission electron microscopy (TEM) and z-scan technique. The size of these nanoparticles was found to be in the range of 12-22 nm as analyzed using transmission electron micrographs. The optical properties of gold nanoparticles have been measured showing the surface plasmon resonance. The second-order nonlinear optical (NLO) properties were investigated by using a continuous-wave (CW) He-Ne laser beam with a wavelength of 632.8 nm at three different incident intensities by means of single beam techniques. The nonlinear refractive indices of gold nanoparticles were obtained from close aperture z-scan in order of 10-7 cm2/W. Then, they were compared with diffraction patterns observed in far-field. The nonlinear absorption of these nanoparticles was obtained from open aperture z-scan technique. The values of nonlinear absorption coefficient are obtained in order of 10-1 cm/W.

  17. Hadron Optics: Diffraction Patterns in Deeply Virtual Compton Scattering

    SciTech Connect

    Brodsky, S

    2006-05-16

    We show that the Fourier transform of the Deeply Virtual Compton Scattering (DVCS) amplitude with respect to the skewness variable {zeta} provides a unique way to visualize the light-front wavefunctions (LFWFs) of the target state in the boost-invariant longitudinal coordinate space variable ({sigma} = P{sup +}y{sup -}/2). The results are analogous to the diffractive scattering of a wave in optics in which the dependence of the amplitude on {sigma} measures the physical size of the scattering center of a one-dimensional system. If one combines this longitudinal transform with the Fourier transform of the DVCS amplitude with respect to the transverse momentum transfer {Delta}{sup {perpendicular}}, one can obtain a complete three-dimensional description of hadron optics at fixed light-front time {tau} = t + z/c. As a specific example, we utilize the quantum fluctuations of a fermion state at one loop in QED to obtain the behavior of the DVCS amplitude for electron-photon scattering. We then simulate the wavefunctions for a hadron by differentiating the above LFWFs with respect to M{sup 2} and study the corresponding DVCS amplitudes in {sigma} space.

  18. Ultra-high accuracy optical testing: creating diffraction-limitedshort-wavelength optical systems

    SciTech Connect

    Goldberg, Kenneth A.; Naulleau, Patrick P.; Rekawa, Senajith B.; Denham, Paul E.; Liddle, J. Alexander; Gullikson, Eric M.; Jackson, KeithH.; Anderson, Erik H.; Taylor, John S.; Sommargren, Gary E.; Chapman,Henry N.; Phillion, Donald W.; Johnson, Michael; Barty, Anton; Soufli,Regina; Spiller, Eberhard A.; Walton, Christopher C.; Bajt, Sasa

    2005-08-03

    Since 1993, research in the fabrication of extreme ultraviolet (EUV) optical imaging systems, conducted at Lawrence Berkeley National Laboratory (LBNL) and Lawrence Livermore National Laboratory (LLNL), has produced the highest resolution optical systems ever made. We have pioneered the development of ultra-high-accuracy optical testing and alignment methods, working at extreme ultraviolet wavelengths, and pushing wavefront-measuring interferometry into the 2-20-nm wavelength range (60-600 eV). These coherent measurement techniques, including lateral shearing interferometry and phase-shifting point-diffraction interferometry (PS/PDI) have achieved RMS wavefront measurement accuracies of 0.5-1-{angstrom} and better for primary aberration terms, enabling the creation of diffraction-limited EUV optics. The measurement accuracy is established using careful null-testing procedures, and has been verified repeatedly through high-resolution imaging. We believe these methods are broadly applicable to the advancement of short-wavelength optical systems including space telescopes, microscope objectives, projection lenses, synchrotron beamline optics, diffractive and holographic optics, and more. Measurements have been performed on a tunable undulator beamline at LBNL's Advanced Light Source (ALS), optimized for high coherent flux; although many of these techniques should be adaptable to alternative ultraviolet, EUV, and soft x-ray light sources. To date, we have measured nine prototype all-reflective EUV optical systems with NA values between 0.08 and 0.30 (f/6.25 to f/1.67). These projection-imaging lenses were created for the semiconductor industry's advanced research in EUV photolithography, a technology slated for introduction in 2009-13. This paper reviews the methods used and our program's accomplishments to date.

  19. Holographically recorded photopolymer diffractive optical element for holographic and electronic speckle-pattern interferometry

    NASA Astrophysics Data System (ADS)

    Guntaka, Sridhar Reddy; Toal, Vincent; Martin, Suzanne

    2002-12-01

    A diffractive optical element is described that can be used to implement a very simple self-aligning electronic speckle-pattern interferometer and holographic interferometer that requires only a laser source and a camera in the optical setup.

  20. Surface micro-structuring of glassy carbon for precision glass molding of diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Prater, Karin; Dukwen, Julia; Scharf, Toralf; Herzig, Hans Peter; Hermerschmidt, Andreas

    2014-09-01

    Glassy carbon is used nowadays for a variety of applications because of its mechanical strength, thermal stability and non-sticking adhesion properties. This makes it also a suitable candidate as mold material for precision compression molding of low and high glass-transition temperature materials. To fabricate molds for diffractive optics a highresolution structuring technique is needed. We introduce a process that allows the micro-structuring of glassy carbon by reactive ion etching. Key parameters such as uniformity, surface roughness, edge definition and lateral resolution are discussed. They are the most relevant parameters for a stamp in optical applications. The use of titanium as a hard mask makes it possible to achieve a reasonable selectivity of 4:1, which has so far been one of the main problems in microstructuring of glassy carbon. We investigate the titanium surface structure with its 5-10 nm thick layer of TiO2 grains and its influence on the shape of the hard mask. In our fabrication procedure we were able to realize optically flat diffractive structures with slope angles of more than 80° at typical feature sizes of 5 μm and at 700 nm depth. The fabricated glassy carbon molds were applied to thermal imprinting onto different glasses. Glassy carbon molds with 1 mm thickness were tested with binary optical structures. Our experiments show the suitability of glassy carbon as molds for cost efficient mass production with a high quality.

  1. Simultaneous multispectral framing infrared camera using an embedded diffractive optical lenslet array

    NASA Astrophysics Data System (ADS)

    Hinnrichs, Michele

    2011-06-01

    Recent advances in micro-optical element fabrication using gray scale technology have opened up the opportunity to create simultaneous multi-spectral imaging with fine structure diffractive lenses. This paper will discuss an approach that uses diffractive optical lenses configured in an array (lenslet array) and placed in close proximity to the focal plane array which enables a small compact simultaneous multispectral imaging camera [1]. The lenslet array is designed so that all lenslets have a common focal length with each lenslet tuned for a different wavelength. The number of simultaneous spectral images is determined by the number of individually configured lenslets in the array. The number of spectral images can be increased by a factor of 2 when using it with a dual-band focal plane array (MWIR/LWIR) by exploiting multiple diffraction orders. In addition, modulation of the focal length of the lenslet array with piezoelectric actuation will enable spectral bin fill-in allowing additional spectral coverage while giving up simultaneity. Different lenslet array spectral imaging concept designs are presented in this paper along with a unique concept for prefiltering the radiation focused on the detector. This approach to spectral imaging has applications in the detection of chemical agents in both aerosolized form and as a liquid on a surface. It also can be applied to the detection of weaponized biological agent and IED detection in various forms from manufacturing to deployment and post detection during forensic analysis.

  2. Numerical simulation of optical vortex propagation and reflection by the methods of scalar diffraction theory

    SciTech Connect

    Petrov, Nikolay V; Pavlov, Pavel V; Malov, A N

    2013-06-30

    Using the equations of scalar diffraction theory we consider the formation of an optical vortex on a diffractive optical element. The algorithms are proposed for simulating the processes of propagation of spiral wavefronts in free space and their reflections from surfaces with different roughness parameters. The given approach is illustrated by the results of numerical simulations. (propagation of wave fronts)

  3. Diffraction leveraged modulation of X-ray pulses using MEMS-based X-ray optics

    DOEpatents

    Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

    2016-08-09

    A method and apparatus are provided for implementing Bragg-diffraction leveraged modulation of X-ray pulses using MicroElectroMechanical systems (MEMS) based diffractive optics. An oscillating crystalline MEMS device generates a controllable time-window for diffraction of the incident X-ray radiation. The Bragg-diffraction leveraged modulation of X-ray pulses includes isolating a particular pulse, spatially separating individual pulses, and spreading a single pulse from an X-ray pulse-train.

  4. Programmable diffractive optical elements for extending the depth of focus in ophthalmic optics

    NASA Astrophysics Data System (ADS)

    Romero, Lenny A.; Millán, María. S.; Jaroszewicz, Zbigniew; Kołodziejczyk, Andrzej

    2015-01-01

    The depth of focus (DOF) defines the axial range of high lateral resolution in the image space for object position. Optical devices with a traditional lens system typically have a limited DOF. However, there are applications such as in ophthalmology, which require a large DOF in comparison to a traditional optical system, this is commonly known as extended DOF (EDOF). In this paper we explore Programmable Diffractive Optical Elements (PDOEs), with EDOF, as an alternative solution to visual impairments, especially presbyopia. These DOEs were written onto a reflective liquid cystal on silicon (LCoS) spatial light modulator (SLM). Several designs of the elements are analyzed: the Forward Logarithmic Axicon (FLAX), the Axilens (AXL), the Light sword Optical Element (LSOE), the Peacock Eye Optical Element (PE) and Double Peacock Eye Optical Element (DPE). These elements focus an incident plane wave into a segment of the optical axis. The performances of the PDOEs are compared with those of multifocal lenses. In all cases, we obtained the point spread function and the image of an extended object. The results are presented and discussed.

  5. From Cartesian to polar: a new POLICRYPS geometry for realizing circular optical diffraction gratings.

    PubMed

    Alj, Domenico; Caputo, Roberto; Umeton, Cesare

    2014-11-01

    We report on the realization of a liquid crystal (LC)-based optical diffraction grating showing a polar symmetry of the director alignment. This has been obtained as a natural evolution of the POLICRYPS technique, which enables the realization of highly efficient, switchable, planar diffraction gratings. Performances exhibited in the Cartesian geometry are extended to the polar one by exploiting the spherical aberration produced by simple optical elements. This enables producing the required highly stable polar pattern that allows fabricating a circular optical diffraction grating. Results are promising for their possible application in fields in which a rotational structure of the optical beam is needed. PMID:25361314

  6. Multiple-Zone Diffractive Optic Element for Laser Ranging Applications

    NASA Technical Reports Server (NTRS)

    Ramos-Izquierdo, Luis A.

    2011-01-01

    A diffractive optic element (DOE) can be used as a beam splitter to generate multiple laser beams from a single input laser beam. This technology has been recently used in LRO s Lunar Orbiter Laser Altimeter (LOLA) instrument to generate five laser beams that measure the lunar topography from a 50-km nominal mapping orbit (see figure). An extension of this approach is to use a multiple-zone DOE to allow a laser altimeter instrument to operate over a wider range of distances. In particular, a multiple-zone DOE could be used for applications that require both mapping and landing on a planetary body. In this case, the laser altimeter operating range would need to extend from several hundred kilometers down to a few meters. The innovator was recently involved in an investigation how to modify the LOLA instrument for the OSIRIS asteroid mapping and sample return mission. One approach is to replace the DOE in the LOLA laser beam expander assembly with a multiple-zone DOE that would allow for the simultaneous illumination of the asteroid with mapping and landing laser beams. The proposed OSIRIS multiple-zone DOE would generate the same LOLA five-beam output pattern for high-altitude topographic mapping, but would simultaneously generate a wide divergence angle beam using a small portion of the total laser energy for the approach and landing portion of the mission. Only a few percent of the total laser energy is required for approach and landing operations as the return signal increases as the inverse square of the ranging height. A wide divergence beam could be implemented by making the center of the DOE a diffractive or refractive negative lens. The beam energy and beam divergence characteristics of a multiple-zone DOE could be easily tailored to meet the requirements of other missions that require laser ranging data. Current single-zone DOE lithographic manufacturing techniques could also be used to fabricate a multiple-zone DOE by masking the different DOE zones during

  7. Optical beam shaping and diffraction free waves: A variational approach

    NASA Astrophysics Data System (ADS)

    Gemmer, John A.; Venkataramani, Shankar C.; Durfee, Charles G.; Moloney, Jerome V.

    2014-08-01

    We investigate the problem of shaping radially symmetric annular beams into desired intensity patterns along the optical axis. Within the Fresnel approximation, we show that this problem can be expressed in a variational form equivalent to the one arising in phase retrieval. Using the uncertainty principle we prove various rigorous lower bounds on the functional; these lower bounds estimate the L2 error for the beam shaping problem in terms of the design parameters. We also use the method of stationary phase to construct a natural ansatz for a minimizer in the short wavelength limit. We illustrate the implications of our results by applying the method of stationary phase coupled with the Gerchberg-Saxton algorithm to beam shaping problems arising in the remote delivery of beams and pulses.

  8. Large-scale optical diffraction tomography for inspection of optical plastic lenses.

    PubMed

    Kim, Kyoohyun; Yoon, Jonghee; Park, YongKeun

    2016-03-01

    Herein is presented an optical diffraction tomography (ODT) technique for measuring 3-D refractive index (RI) maps of optical plastic lenses. A Mach-Zehnder interferometer was used to measure multiple complex optical fields of a plastic lens immersed in RI-matching oil at various rotational orientations. From this, ODT was used to reconstruct a 3-D RI distribution of the plastic lens with unprecedented RI sensitivity (Δn=4.21×10(-5) and high resolution (12.8 μm). As a demonstration, 3-D RI distributions of a 2 mm-diameter borosilicate sphere and a 5 mm-diameter plastic lens were reconstructed. Defects in the lens, generated by pulsed laser ablation, were also detected using the present method. PMID:26974084

  9. An optical metamaterial with simultaneously suppressed optical diffraction and surface reflection

    NASA Astrophysics Data System (ADS)

    Kivijärvi, V.; Nyman, M.; Shevchenko, A.; Kaivola, M.

    2016-03-01

    Diffraction-free propagation of light has been demonstrated in free space for Bessel-like beams and for arbitrary beams in specially designed photonic crystals and metamaterials. The phenomenon is called self-collimation in photonic crystals and canalization in metamaterials, as the approaches to obtaining the effect are different. In both cases, however, diffraction-free propagation of light is achieved by making the dispersion surface of the material at a given frequency flat. In photonic crystals this is done by tuning the unit-cell dimensions close to the band-gap regime, and in metamaterials by tuning a hyperbolic-type metamaterial towards its transition to an ordinary elliptical metamaterial. In this work, we propose an alternative way to suppress optical diffraction in a metamaterial by adjusting the anisotropy of the finite-sized three-dimensional metamolecules and the material’s spatial dispersion. The approach allows matching the wave impedance of the material to that of the surrounding medium in a wide range of incidence angles and thereby also suppressing optical reflection from the material’s surface.

  10. Optical devices combining an organic semiconductor crystal with a two-dimensional inorganic diffraction grating

    NASA Astrophysics Data System (ADS)

    Kitazawa, Takenori; Yamao, Takeshi; Hotta, Shu

    2016-02-01

    We have fabricated optical devices using an organic semiconductor crystal as an emission layer in combination with a two-dimensional (2D) inorganic diffraction grating used as an optical cavity. We formed the inorganic diffraction grating by wet etching of aluminum-doped zinc oxide (AZO) under a 2D cyclic olefin copolymer (COC) diffraction grating used as a mask. The COC diffraction grating was fabricated by nanoimprint lithography. The AZO diffraction grating was composed of convex prominences arranged in a triangular lattice. The organic crystal placed on the AZO diffraction grating indicated narrowed peaks in its emission spectrum under ultraviolet light excitation. These are detected parallel to the crystal plane. The peaks were shifted by rotating the optical devices around the normal to the crystal plane, which reflected the rotational symmetries of the triangular lattice through 60°.

  11. Planar super-oscillatory lens for sub-diffraction optical needles at violet wavelengths

    PubMed Central

    Yuan, Guanghui; Rogers, Edward T. F.; Roy, Tapashree; Adamo, Giorgio; Shen, Zexiang; Zheludev, Nikolay I.

    2014-01-01

    Planar optical lenses are fundamental elements of miniaturized photonic devices. However, conventional planar optical lenses are constrained by the diffraction limit in the optical far-field due to the band-limited wavevectors supported by free-space and loss of high-spatial-frequency evanescent components. As inspired by Einstein's radiation ‘needle stick', electromagnetic energy can be delivered into an arbitrarily small solid angle. Such sub-diffraction optical needles have been numerically investigated using diffractive optical elements (DOEs) together with specially polarized optical beams, but experimental demonstration is extremely difficult due to the bulky size of DOEs and the required alignment precision. Planar super-oscillatory lenses (SOLs) were proposed to overcome these constraints and demonstrated that sub-diffraction focal spots can actually be formed without any evanescent waves, making far-field, label-free super-resolution imaging possible. Here we extend the super-oscillation concept into the vectorial-field regime to work with circularly polarized light, and experimentally demonstrate, for the first time, a circularly polarized optical needle with sub-diffraction transverse spot size (0.45λ) and axial long depth of focus (DOF) of 15λ using a planar SOL at a violet wavelength of 405 nm. This sub-diffraction circularly polarized optical needle has potential applications in circular dichroism spectroscopy, super-resolution imaging, high-density optical storage, heat-assisted magnetic recording, nano-manufacturing and nano-metrology. PMID:25208611

  12. Diffractive optics fabricated by direct write methods with an electron beam

    NASA Technical Reports Server (NTRS)

    Kress, Bernard; Zaleta, David; Daschner, Walter; Urquhart, Kris; Stein, Robert; Lee, Sing H.

    1993-01-01

    State-of-the-art diffractive optics are fabricated using e-beam lithography and dry etching techniques to achieve multilevel phase elements with very high diffraction efficiencies. One of the major challenges encountered in fabricating diffractive optics is the small feature size (e.g. for diffractive lenses with small f-number). It is not only the e-beam system which dictates the feature size limitations, but also the alignment systems (mask aligner) and the materials (e-beam and photo resists). In order to allow diffractive optics to be used in new optoelectronic systems, it is necessary not only to fabricate elements with small feature sizes but also to do so in an economical fashion. Since price of a multilevel diffractive optical element is closely related to the e-beam writing time and the number of etching steps, we need to decrease the writing time and etching steps without affecting the quality of the element. To do this one has to utilize the full potentials of the e-beam writing system. In this paper, we will present three diffractive optics fabrication techniques which will reduce the number of process steps, the writing time, and the overall fabrication time for multilevel phase diffractive optics.

  13. Optical Diffraction in Close Proximity to Plane Apertures. II. Comparison of Half-Plane Diffraction Theories

    PubMed Central

    Mielenz, Klaus D.

    2003-01-01

    The accuracy and physical significance of the classical Rayleigh-Sommerfeld and Kirchhoff diffraction integrals are assessed in the context of Sommerfeld’s rigorous theory of half-plane diffraction and Maxwell’s equations. It is shown that the Rayleigh-Sommerfeld integrals are in satisfactory agreement with Sommerfeld’s theory in most of the positive near zone, except at sub-wavelength distances from the screen. On account of the bidirectional nature of diffraction by metallic screens the Rayleigh-Sommerfeld integrals themselves cannot be used for irradiance calculations, but must first be resolved into their forward and reverse components and it is found that Kirchhoff’s integral is the appropriate measure of the forward irradiance. Because of the inadequate boundary conditions assumed in their derivation the Rayleigh-Sommerfeld and Kirchhoff integrals do not correctly describe the flow of energy through the aperture.

  14. Development of a Compact Optical-MEMS Scanner with Integrated VCSEL Light Source and Diffractive Optics

    SciTech Connect

    Krygowski, Thomas W.; Reyes, David; Rodgers, M. Steven; Smith, James H.; Warren, Mial; Sweatt, William; Blum-Spahn, Olga; Wendt, Joel R.; Asbill, Randy

    1999-06-30

    In this work the design and initial fabrication results are reported for the components of a compact optical-MEMS laser scanning system. This system integrates a silicon MEMS laser scanner, a Vertical Cavity Surface Emitting Laser (VCSEL) and passive optical components. The MEMS scanner and VCSEL are mounted onto a fused silica substrate which serves as an optical interconnect between the devices. Two Diffractive Optical Elements (DOEs) are etched into the fused silica substrate to focus the VCSEL beam and increase the scan range. The silicon MEMS scanner consists of an actuator that continuously scans the position of a large polysilicon gold-coated shuttle containing a third DOE. Interferometric measurements show that the residual stress in the 500 {micro}m x 1000 {micro}m shuttle is extremely low, with a maximum deflection of only 0.18{micro}m over an 800 {micro}m span for an unmetallized case and a deflection of 0.56{micro}m for the metallized case. A conservative estimate for the scan range is {approximately}{+-}4{degree}, with a spot size of about 0.5 mm, producing 50 resolvable spots. The basic system architecture, optical and MEMS design is reported in this paper, with an emphasis on the design and fabrication of the silicon MEMS scanner portion of the system.

  15. Beam Size Measurement by Optical Diffraction Radiation and Laser System for Compton Polarimeter

    SciTech Connect

    Liu, Chuyu

    2012-12-31

    difficulty of diagnostics. For most cases, intercepting measurements are no longer acceptable, and nonintercepting method like synchrotron radiation monitor can not be applied to linear accelerators. The development of accelerator technology asks for simutanous diagnostics innovations, to expand the performance of diagnostic tools to meet the requirements of the next generation accelerators. Diffraction radiation and inverse Compton scattering are two of the most promising techniques, their nonintercepting nature avoids perturbance to the beam and damage to the instrumentation. This thesis is divided into two parts, beam size measurement by optical diffraction radiation and Laser system for Compton polarimeter. Diffraction radiation, produced by the interaction between the electric field of charged particles and the target, is related to transition radiation. Even though the theory of diffraction radiation has been discussed since 1960s, there are only a few experimental studies in recent years. The successful beam size measurement by optical diffraction radiation at CEBAF machine is a milestone: First of all, we have successfully demonstrated diffraction radiation as an effective nonintercepting diagnostics; Secondly, the simple linear relationship between the diffraction radiation image size and the actual beam size improves the reliability of ODR measurements; And, we measured the polarized components of diffraction radiation for the first time and I analyzed the contribution from edge radiation to diffraction radiation.

  16. Tolerancing of single point diamond turned diffractive optical elements and optical surfaces

    NASA Astrophysics Data System (ADS)

    Bittner, R. F.

    2007-10-01

    Single point diamond turning has an increasing importance with the production of the surfaces for different optical systems such as infrared systems, prototype production of mobile phone cameras or head mounted displays with plastic lenses or master manufacturing for the injection moulding of plastic lenses for mass products. Tolerances which occur during single point diamond turning of aspheric surfaces and diffractive elements or during polar coordinate laser plotting of Computer-generated holograms will be treated. In both cases we expect similar tolerances, because the work piece is rotated in both diamond turning and laser plotting. The purpose is to understand the typical tolerances and to simulate their influence to the aberrations in the optical system.

  17. Research of the new optical diffractive super-resolution element of the two-photon microfabrication

    NASA Astrophysics Data System (ADS)

    Wei, Peng; Zhu, Yu; Duan, Guanghong

    2006-11-01

    The new optical diffractive superresolution element (DSE) is being applied to improve the microfabrication radial superresolution in the two-photon three-dimension (3D) microfabrication system, which appeared only a few years ago and can provide the ability to confine photochemical and physical reactions to the order of laser wavelength in three dimensions. The design method of the DSE is that minimizing M if the lowest limit S l of the S and the highest limit G u of the G is set, where Liu [1] explained the definition of the S, M and G. Simulation test result proved that the microfabrication radial superresolution can be improved by the new optical DSE. The phenomenon can only be interpreted as the intensity of high-order and side of the zero-order diffraction peaks have been clapped under the twophoton absorption (TPA) polymerization threshold. In a word the polymerized volume can be chosen because the S l and the G u is correspondingly adjustable, even if the laser wavelength, objective lens and the photosensitive resin is fixed for a given two-photon microfabrication system. That means the radial superresolution of the two-photon microfabrication can be chosen.

  18. Diffractive optics for combined spatial- and mode- division demultiplexing of optical vortices: design, fabrication and optical characterization.

    PubMed

    Ruffato, Gianluca; Massari, Michele; Romanato, Filippo

    2016-01-01

    During the last decade, the orbital angular momentum (OAM) of light has attracted growing interest as a new degree of freedom for signal channel multiplexing in order to increase the information transmission capacity in today's optical networks. Here we present the design, fabrication and characterization of phase-only diffractive optical elements (DOE) performing mode-division (de)multiplexing (MDM) and spatial-division (de)multiplexing (SDM) at the same time. Samples have been fabricated with high-resolution electron-beam lithography patterning a polymethylmethacrylate (PMMA) resist layer spun over a glass substrate. Different DOE designs are presented for the sorting of optical vortices differing in either OAM content or beam size in the optical regime, with different steering geometries in far-field. These novel DOE designs appear promising for telecom applications both in free-space and in multi-core fibers propagation. PMID:27094324

  19. Diffractive optics for combined spatial- and mode- division demultiplexing of optical vortices: design, fabrication and optical characterization

    PubMed Central

    Ruffato, Gianluca; Massari, Michele; Romanato, Filippo

    2016-01-01

    During the last decade, the orbital angular momentum (OAM) of light has attracted growing interest as a new degree of freedom for signal channel multiplexing in order to increase the information transmission capacity in today’s optical networks. Here we present the design, fabrication and characterization of phase-only diffractive optical elements (DOE) performing mode-division (de)multiplexing (MDM) and spatial-division (de)multiplexing (SDM) at the same time. Samples have been fabricated with high-resolution electron-beam lithography patterning a polymethylmethacrylate (PMMA) resist layer spun over a glass substrate. Different DOE designs are presented for the sorting of optical vortices differing in either OAM content or beam size in the optical regime, with different steering geometries in far-field. These novel DOE designs appear promising for telecom applications both in free-space and in multi-core fibers propagation. PMID:27094324

  20. Diffractive optics for combined spatial- and mode- division demultiplexing of optical vortices: design, fabrication and optical characterization

    NASA Astrophysics Data System (ADS)

    Ruffato, Gianluca; Massari, Michele; Romanato, Filippo

    2016-04-01

    During the last decade, the orbital angular momentum (OAM) of light has attracted growing interest as a new degree of freedom for signal channel multiplexing in order to increase the information transmission capacity in today’s optical networks. Here we present the design, fabrication and characterization of phase-only diffractive optical elements (DOE) performing mode-division (de)multiplexing (MDM) and spatial-division (de)multiplexing (SDM) at the same time. Samples have been fabricated with high-resolution electron-beam lithography patterning a polymethylmethacrylate (PMMA) resist layer spun over a glass substrate. Different DOE designs are presented for the sorting of optical vortices differing in either OAM content or beam size in the optical regime, with different steering geometries in far-field. These novel DOE designs appear promising for telecom applications both in free-space and in multi-core fibers propagation.

  1. Wide-aperture diffraction of unpolarised radiation in a system of two acousto-optic filters

    SciTech Connect

    Magdich, L N; Yushkov, K B; Voloshinov, V B

    2009-04-30

    Light diffraction is studied in two tandem acousto-optic cells filtering unpolarised radiation with a wide angular spectrum. It is shown that the side lobes of the ultrasonic radiation pattern of a piezoelectric transducer produce side diffraction intensity maxima at the output of the system consisting of two filters. Diffraction in paratellurite filters is studied experimentally at 1.06 {mu}m. (light modulation)

  2. Bragg diffraction of light by ultrasonic waves in planargyrotrophic optical waveguides in an external electric field

    SciTech Connect

    Kulak, G.V.

    1995-09-01

    Features of Bragg diffraction of light by two-partial surface ultrasonic waves in planar gyrotropic optical waveguides placed in an external electric field are considered. General expressions for complex vector amplitudes of diffracted fields are presented. It is shown that the diffracted waves have elliptic polarization, the ellipticity being determined by the linear anisotropy of the waveguide structure, the anisotropy induced by an external electric field, the anisotropy of photoelasticity, and the crystal gyrotropy. 16 refs., 2 figs.

  3. Design and experiments of combined diffractive optical element for virtual displays and indicators

    NASA Astrophysics Data System (ADS)

    Odinokov, Sergey B.; Ruchkina, Maria A.; Sagatelyan, Gaik R.; Solomashenko, Artem B.; Zherdev, Alexander Y.

    2015-05-01

    Combined diffractive optical elements, which perform the functions of deflection, focusing or transformation of wave fronts and together with the spectral-angular selection of the incident polychromatic radiation, obtained on a single substrate, the method of their design and fabrication are described. The combination of four-level diffraction grating with plasmon meander diffraction grating as a spectral filter that have a bandwidth that varies with the angle of incidence are investigated for use in virtual displays and indicators.

  4. Programmable diffractive optical element using a multichannel lanthanum-modified lead zirconate titanate phase modulator

    NASA Astrophysics Data System (ADS)

    Thomas, James A.; Fainman, Yeshaiahu

    1995-07-01

    We introduce a programmable diffractive optical element based on an electro-optic phased array implemented with a multichannel lanthanum-modified lead zirconate titanate phase modulator. The design and fabrication procedures are outlined, along with an experimental demonstration of the device. Experimental results from a 16-channel device operating with a 2 pi voltage of 300 V demonstrate selective beam steering. The programmable diffractive optical element allows for efficient, high-speed high-resolution random-access optical beam steering over a continuous scanning range.

  5. Tunable Diffractive Optical Elements Based on Shape-Memory Polymers Fabricated via Hot Embossing.

    PubMed

    Schauer, Senta; Meier, Tobias; Reinhard, Maximilian; Röhrig, Michael; Schneider, Marc; Heilig, Markus; Kolew, Alexander; Worgull, Matthias; Hölscher, Hendrik

    2016-04-13

    We introduce actively tunable diffractive optical elements fabricated from shape-memory polymers (SMPs). By utilizing the shape-memory effect of the polymer, at least one crucial attribute of the diffractive optical element (DOE) is tunable and adjustable subsequent to the completed fabrication process. A thermoplastic, transparent, thermoresponsive polyurethane SMP was structured with diverse diffractive microstructures via hot embossing. The tunability was enabled by programming a second, temporary shape into the diffractive optical element by mechanical deformation, either by stretching or a second embossing cycle at low temperatures. Upon exposure to the stimulus heat, the structures change continuously and controllable in a predefined way. We establish the novel concept of shape-memory diffractive optical elements by illustrating their capabilities, with regard to tunability, by displaying the morphing diffractive pattern of a height tunable and a period tunable structure, respectively. A sample where an arbitrary structure is transformed to a second, disparate one is illustrated as well. To prove the applicability of our tunable shape-memory diffractive optical elements, we verified their long-term stability and demonstrated the precise adjustability with a detailed analysis of the recovery dynamics, in terms of temperature dependence and spatially resolved, time-dependent recovery. PMID:26998646

  6. Realization of binary radial diffractive optical elements by two-photon polymerization technique.

    PubMed

    Osipov, Vladimir; Pavelyev, Vladimir; Kachalov, Denis; Zukauskas, Albertas; Chichkov, Boris

    2010-12-01

    Application of the two-photon polymerization (2PP) technique for the fabrication of submicron-size relief of radial binary diffractive optical elements (DOE's) is studied. Binary DOE's for the formation of special longitudinal intensity distribution (axial light segment) are realized. Interferometric investigations of the diffractive relief produced by the 2PP-technique and investigations of optical properties of the formed elements are presented. Results of computer simulations are in good agreement with the experimental observations. PMID:21164925

  7. Near-field focusing of an optical wave by diffraction gratings

    NASA Astrophysics Data System (ADS)

    Geints, Yu E.; Zemlyanov, A. A.

    2016-07-01

    We report the investigation results for spatially-localised light structures (photonic nanojets) under near-field optical radiation scattering on phase diffraction gratings. Main parameters of photonic nanojets from gratings with sawtooth, rectangular and hemispherical groove profiles are obtained by numerical electrodynamic simulation. It is found that by varying a period, degree of filling, groove shape and parameters of optically contrast coating of the diffraction grating one can control the characteristics of the produced photonic jets in a wide range.

  8. Dielectric barrier discharges applied for optical spectrometry

    NASA Astrophysics Data System (ADS)

    Brandt, S.; Schütz, A.; Klute, F. D.; Kratzer, J.; Franzke, J.

    2016-09-01

    The present review reflects the importance of dielectric barrier discharges for optical spectrometric detection in analytical chemistry. In contrast to usual discharges with a direct current the electrodes are separated by at least one dielectric barrier. There are two main features of the dielectric barrier discharges: they can serve as dissociation and excitation devices as well as ionization sources, respectively. This article portrays various application fields of dielectric barrier discharges in analytical chemistry used for elemental and molecular detection with optical spectrometry.

  9. A complete digital optics applied to digital holographic microscopy: application to chromatic aberration compensation

    NASA Astrophysics Data System (ADS)

    Colomb, Tristan; Charrière, Florian; Kühn, Jonas; Montfort, Frédéric; Depeursinge, Christian

    2007-06-01

    In optics, optical elements are used to transform, to filter or to process physical wavefronts in order to magnify images, compensate for aberration or to suppress unwanted diffracted order for example. Because digital holography provides numerical wavefronts, we developed a digital optics, involving numerical elements such as numerical lenses and pinholes, to mimic numerically what is usually done physically, with the advantage to be able to define any shape for these elements and to place them everywhere without obstruction problems. We demonstrate that automatic and non-automatic procedures allow diffracted order or parasitic interferences filtering, compensation for aberration and image distortion, and control of position and magnification of reconstructed wavefront. We apply this digital optics to compensate for chromatic aberration in multi-wavelength holography in order to have perfect superposition between wavefronts reconstructed from digital hologram recorded with different wavelengths. This has a great importance for synthetic wavelength digital holography or tomographic digital holography that use multiple wavelengths.

  10. MEMS-based diffractive optical-beam-steering technology

    NASA Astrophysics Data System (ADS)

    Winick, David A.; Duewer, Bruce E.; Chaudhury, Som; Wilson, John M.; Tucker, John; Eksi, Umut; Franzon, Paul D.

    1998-03-01

    This paper presents some results from phase-1 research into developing a beam steerer based on micro-mechanical diffractive elements. The position of these elements is electrostatically controlled, to allow dynamic programming of a 2D phase function. Feasibility prototypes were constructed in the MUMPs polysilicon surface micromachine process.

  11. A discrimination analysis for unsupervised feature selection via optic diffraction principle.

    PubMed

    Padungweang, Praisan; Lursinsap, Chidchanok; Sunat, Khamron

    2012-10-01

    This paper proposes an unsupervised discrimination analysis for feature selection based on a property of the Fourier transform of the probability density distribution. Each feature is evaluated on the basis of a simple observation motivated by the concept of optical diffraction, which is invariant under feature scaling. The time complexity is O(mn), where m is number of features and n is number of instances when being applied directly to the given data. This approach is also extended to deal with data orientation, which is the direction of data alignment. Therefore, the discrimination score of any transformed space can be used for evaluating the original features. The experimental results on several real-world datasets demonstrate the effectiveness of the proposed method. PMID:24808004

  12. Diffractive optical element with asymmetric microrelief for creating visual security features.

    PubMed

    Goncharsky, Alexander; Goncharsky, Anton; Durlevich, Svyatoslav

    2015-11-01

    We demonstrate a new security feature for visual control of the authenticity of optical security features - the change of the images when the optical element is turned by 180 degrees ("switch-180°"). The diffractive optical element has an asymmetric microrelief structure resulting from the asymmetry of the scattering pattern. The phase function of the diffractive optical element is computed in terms of Fresnel's scalar wave model. We developed efficient algorithms for computing the structure of flat optical elements to produce the switch effect. A sample of flat optical element for the "switch-180" effect has been developed using electron-beam lithography. The effectiveness of the development is illustrated by the photos and the video captured from a real sample. The visual "switch-180°" effect is easy to control allowing secure anti-counterfeit protection of the optical security feature developed. The new security feature is already used to protect IDs and excise stamps. PMID:26561188

  13. Fabrication of Diffractive Optical Elements for an Integrated Compact Optical-MEMS Laser Scanner

    SciTech Connect

    WENDT,JOEL R.; KRYGOWSKI,T.W.; VAWTER,GREGORY A.; SPAHN,OLGA B.; SWEATT,WILLIAM C.; WARREN,MIAL E.; REYES,DAVID NMN

    2000-07-13

    The authors describe the microfabrication of a multi-level diffractive optical element (DOE) onto a micro-electromechanical system (MEMS) as a key element in an integrated compact optical-MEMS laser scanner. The DOE is a four-level off-axis microlens fabricated onto a movable polysilicon shuttle. The microlens is patterned by electron beam lithography and etched by reactive ion beam etching. The DOE was fabricated on two generations of MEMS components. The first generation design uses a shuttle suspended on springs and displaced by a linear rack. The second generation design uses a shuttle guided by roller bearings and driven by a single reciprocating gear. Both the linear rack and the reciprocating gear are driven by a microengine assembly. The compact design is based on mounting the MEMS module and a vertical cavity surface emitting laser (VCSEL) onto a fused silica substrate that contains the rest of the optical system. The estimated scan range of the system is {+-}4{degree} with a spot size of 0.5 mm.

  14. About diffusers and their importance in diffractive optics

    NASA Astrophysics Data System (ADS)

    Wyrowski, Frank; Schimmel, Hagen

    2006-08-01

    With their introduction of diffused illumination Leith and Upatnieks introduced one the most essential inventions in holography and in modern optical engineering in general. They observed for the first time the enormous capability of utilizing the phase of a light field in a random-like manner for manipulating its characteristics when propagating in space. The use of phase freedom beyond lens-like manipulations in optical engineering was born. We like to place their invention into a broader context and discuss its enormous impact on most actual developments in optical engineering.

  15. Enhancement of RIE: etched Diffractive Optical Elements surfaces by using Ion Beam Etching

    NASA Astrophysics Data System (ADS)

    Schmitt, J.; Bischoff, Ch.; Rädel, U.; Grau, M.; Wallrabe, U.; Völklein, F.

    2015-09-01

    Shaping of laser light intensities by using Diffractive Optical Elements allows the adaption of the incident light to its application. Fused silica is used where for example UV-light or high temperatures are mandatory. For high diffraction efficiency the quality of the etched surface areas is important. The investigation of different process parameters for Ion Beam and Reactive Ion Etching reveals that only Ion Beam Etching provides surfaces with optical quality. Measurements of the influence of the surface quality on the diffraction efficiencies prove that the surfaces generated by Reactive Ion Etching are not suitable. Due to the high selectivity of the process Reactive Ion Etching is nevertheless a reasonable choice for the fabrication of Diffractive Optical Elements. To improve the quality of the etched surfaces a post processing with Ion Beam Etching is developed. Simulations in MATLAB display that the angle dependent removal of the surface during the Ion Beam Etching causes a smoothing of the surface roughness. The positive influence of a post processing on the diffraction efficiency is outlined by measurements. The ion beam post processing leads to an increase of the etching depth. For the fabrication of high efficient Diffractive Optical Elements this has to be taken into account. The relation is investigated and transferred to the fabrication of four-level gratings. Diffraction efficiencies up to 78 % instead of the ideal 81 % underline the practicability of the developed post processing.

  16. Sub-cellular quantitative optical diffraction tomography with digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Charrière, Florian; Kühn, Jonas; Colomb, Tristan; Cuche, Etienne; Marquet, Pierre; Depeursinge, Christian

    2007-02-01

    Digital holographic microscopy (DHM) is an interferometric technique, providing quantitative mapping of the phase shift induced by semi-transparent microscopic specimens, such as cells, with sub-wavelength resolution along the optical axis. Thanks to actual PCs and CCDs, DHM provides nowadays cost-effective instruments for real-time measurements at very high acquisition rates, with sub-micron transverse resolution. However, DHM phase images do not reveal the threedimensional (3D) internal distribution of refractive index, but a phase shift resulting from a mean refractive index (RI) integrated over the cellular thickness. Standard optical diffraction tomography (ODT) techniques can be efficiently applied to reveal internal structures and to measure 3D RI spatial distributions, by recording 2D DHM phase data for different sample orientations or illumination beam direction, in order to fill up entirely the Ewald sphere in the Fourier space. The 3D refractive index can then be reconstructed, even in the direct space with backpropagation algorithms or from the Fourier space with inverse Fourier transform. The presented technique opens wide perspectives in 3D cell imaging: the DHM-based micro-tomography furnishes invaluable data on the cell components optical properties, potentially leading to information about organelles intracellular distribution. Results obtained on biological specimens will be presented. Morphometric measurements can be extracted from the tomographic data, by detection based on the refractive index contrast within the 3D reconstructions. Results and perspectives about sub-cellular organelles identification inside the cell will also be exposed.

  17. Design and fabrication for the diffractive optical element of an infrared system

    NASA Astrophysics Data System (ADS)

    Yang, Changcheng; Li, Shenghui; Li, Yong; Wang, Bin

    2009-05-01

    A diffractive/refractive system with a relative aperture of f/4.0, the EFL of 150mm at 3.7-4.8μm is designed. A diffractive optical element (DOE) is fabricated by means of diamond turning on a conic substrate of the Germanium lens in this system. The characteristics of the diffractive optical element are analyzed in the software of Diffsys. And the zone radius of DOE and step height are detected by profilometry and result is produced. Test results of DOE are coincided with the design figures and the DOE has tiny surface error and high diffractive efficiency. Result of Modulation Transfer Function (MTF) for the system is tested by Ealing and the tested value is closely approximate to diffractive limit. The DOE has better behaviour of chromatic aberration and athermalization.

  18. Design of diffractive optical surfaces within the nonimaging SMS design method

    NASA Astrophysics Data System (ADS)

    Mendes-Lopes, João.; Benítez, Pablo; Miñano, Juan C.

    2015-09-01

    The Simultaneous Multiple Surface (SMS) method was initially developed as a design method in Nonimaging Optics and later, the method was extended for designing Imaging Optics. We show an extension of the SMS method to diffractive surfaces. Using this method, diffractive kinoform surfaces are calculated simultaneously and through a direct method, i. e. it is not based in multi-parametric optimization techniques. Using the phase-shift properties of diffractive surfaces as an extra degree of freedom, only N/2 surfaces are needed to perfectly couple N one parameter wavefronts. Wavefronts of different wavelengths can also be coupled, hence chromatic aberration can be corrected in SMS-based systems. This method can be used by combining and calculating simultaneously both reflective, refractive and diffractive surfaces, through direct calculation of phase and refractive/reflective profiles. Representative diffractive systems designed by the SMS method are presented.

  19. Nanostructured diffractive optical devices for soft X-ray microscopes

    NASA Astrophysics Data System (ADS)

    Hambach, D.; Peuker, M.; Schneider, G.

    2001-07-01

    The new transmission X-ray microscope (TXM) installed at the BESSY II electron storage ring uses an off-axis transmission zone plate (OTZ) as diffractive and focusing element of the condenser-monochromator setup. A high resolution micro-zone plate (MZP) forms a magnified image on a CCD-detector. Both, the OTZ with an active area of up to 24 mm2 and the MZP with zone widths as small as 25 nm are generated by a process including electron beam lithography (EBL), dry etching and subsequent electroplating of nickel on top of silicon membrane substrates with about 100- 150 nm thickness. The combination of a larger zone width and the usage of nickel zone structures allows to increase the diffraction efficiency of the condenser element at least by a factor of 3 compared to the earlier used KZP7 condenser zone plate in the TXM at BESSY I. Groove diffraction efficiencies of 21.6% and 14.7% were measured for MZP objectives with 40 and 25 nm outermost zone width, respectively.

  20. Thermal Weapon Sight (TWS) AN/PAS-13 diffractive optics designed for producibility

    NASA Technical Reports Server (NTRS)

    Anderson, J. Steven; Chen, Chungte W.; Spande, Robert A.

    1993-01-01

    The Thermal Weapon Sight (TWS) program is a manportable 3-5 micrometer forward-looking-infrared (FLIR) rifle sight. The manportable nature requires that the optics modules be lightweight, low cost and compact while maximizing performance. These objectives were met with diffractive optics. TWS promises to be the first FLIR sensor to incorporate kinoform surfaces in full scale production.

  1. (Optical characterization techniques applied to ceramic oxides)

    SciTech Connect

    Abraham, M.M.

    1990-10-15

    The traveler collaborated with M.J.M. Leask, J.M. Baker, B. Bleaney, and others at the Clarendon Laboratory, Oxford University, Oxford, UK, to Study Tetragonal rare-earth phosphates and vanadates by optical and magnetic spectroscopy. This work is related to similar studies that have been performed at ORNL by the Synthesis and Properties of Novel Materials Group in the Solid State Division.

  2. Optical double-image cryptography based on diffractive imaging with a laterally-translated phase grating.

    PubMed

    Chen, Wen; Chen, Xudong; Sheppard, Colin J R

    2011-10-10

    In this paper, we propose a method using structured-illumination-based diffractive imaging with a laterally-translated phase grating for optical double-image cryptography. An optical cryptosystem is designed, and multiple random phase-only masks are placed in the optical path. When a phase grating is laterally translated just before the plaintexts, several diffraction intensity patterns (i.e., ciphertexts) can be correspondingly obtained. During image decryption, an iterative retrieval algorithm is developed to extract plaintexts from the ciphertexts. In addition, security and advantages of the proposed method are analyzed. Feasibility and effectiveness of the proposed method are demonstrated by numerical simulation results. PMID:22015370

  3. Optical characterization of fully programmable MEMS diffraction gratings.

    PubMed

    Zamkotsian, F; Timotijevic, B; Lockhart, R; Stanley, R P; Lanzoni, P; Luetzelschwab, M; Canonica, M; Noell, W; Tormen, M

    2012-11-01

    We have fabricated and characterized fully programmable diffraction gratings consisting of 64 silicon micro-mirrors. The mirrors are 700µm long and 50µm wide with a fill factor of 90%. They are actuated electrostatically and move down by 1.25μm while showing negligible cross-talk and bowing as small as 0.14μm over 700μm. Extinction ratio up to 100 has been achieved by adjusting only 3 adjacent micro-mirrors. The gratings could operate either as light modulators up to 5μm or spectra generators up to 2.5μm. PMID:23187343

  4. Fabrication error analysis for diffractive optical elements used in a lithography illumination system

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Zhang, Fang; Song, Qiang; Zeng, Aijun; Zhu, Jing; Huang, Huijie

    2015-04-01

    With the constant shrinking of printable critical dimensions in photolithography, off-axis illumination (OAI) becomes one of the effective resolution-enhancement methods facing these challenges. This, in turn, is driving much more strict requirements, such as higher diffractive efficiency of the diffractive optical elements (DOEs) used in the OAI system. Since the design algorithms to optimize DOEs' phase profile are improved, the fabrication process becomes the main limiting factor leading to energy loss. Tolerance analysis is the general method to evaluate the fabrication accuracy requirement, which is especially useful for highly specialized deep UV applications with small structures and tight tolerances. A subpixel DOE simulation model is applied for tolerance analysis of DOEs by converting the abstractive fabrication structure errors into quantifiable subpixel phase matrices. Adopting the proposed model, four kinds of fabrication errors including misetch, misalignment, feature size error, and feature rounding error are able to be investigated. In the simulation experiments, systematic fabrication error studies of five typical DOEs used in 90-nm scanning photolithography illumination system are carried out. These results are valuable in the range of high precision DOE design algorithm and fabrication process optimization.

  5. Local improvement of the signal-to-noise ratio for diffractive optical elements designed by unidirectional optimization methods

    NASA Astrophysics Data System (ADS)

    Meister, Martin; Winfield, Richard J.

    2002-12-01

    We present a straightforward method to design multilevel phase-only diffractive optical elements with a locally improved signal-to-noise ratio in the reconstruction. The method is generally applicable to all unidirectional design schemes, such as direct search, simulated annealing, or genetic optimization. As the shape and the location of the desired low noise areas are supplied by a bit map file the method allows for the design of basically any two-dimensional low noise area. The improvement in the signal-to-noise ratio that may be achieved is considerable but also entails reduced diffraction efficiency. The suggested method is applied to different beam-splitter design examples. All examples are calculated with the scalar diffraction approximation in the far field.

  6. Diffractive focusing optics design at Helmholtz-Zentrum Berlin

    NASA Astrophysics Data System (ADS)

    Firsov, Alexander; Brzhezinskaya, Maria; Firsov, Anatoly; Svintsov, Alexander; Erko, Alexei

    2014-09-01

    X-ray laser facilities are being constructed all over the world: Linac Coherent Light Source (LCLS) in California, RIKEN X-Ray Free-Electron Laser at SPring-8 in Japan, European XFEL in Germany etc. XFEL is the next-generation (4th) light source. However, the number of such experimental facilities (SRS and FEL) is quite limited. At the same time, relatively small vacuum ultraviolet laboratories with impulse sources [High Harmonic Generators (HHG)] allow one conduct in-house research. This makes the research community directly involved in experiments with time resolution much wider. The latest radiation sources and modern physical experiments require application of the newest diffractive elements. Such diffractive elements are required for implementation of experiments with time resolution using synchrotron radiation sources or high harmonics generators. For example, valence state evolution or molecules dissociation in time-resolved investigation. Modern experiments like this might require implementation of time resolution in femto - (10-15) and even atto- (10-18) seconds.

  7. Diffraction microgratings as a novel optical biosensing platform

    NASA Astrophysics Data System (ADS)

    Baikova, Tatiana V.; Danilov, Pavel A.; Gonchukov, Sergey A.; Yermachenko, Valery M.; Ionin, Andrey A.; Khmelnitskii, Roman A.; Kudryashov, Sergey I.; Nguyen, Trang T. H.; Rudenko, Andrey A.; Saraeva, Irina N.; Svistunova, Tatiana S.; Zayarny, Dmitry A.

    2016-07-01

    Using a micro-hole grating in a supported silver film as a laser-fabricated novel optical platform for surface-enhanced IR absoprtion/reflection spectroscopy, characteristic absorption bands of Staphylococcus aureus, in particular, its buried carotenoid fragments, were detected in FT-IR spectra with 10-fold analytical enhancement, paving the way for the spectral express-identification of pathogenic microorganisms.

  8. Optical diffraction in ordered VO2 nanoparticle arrays

    NASA Astrophysics Data System (ADS)

    Lopez, Rene; Feldman, Leonard; Haglund, Richard

    2006-03-01

    The potential of oxide electronic materials as multifunctional building blocks is one of the driving concepts of the field. In this presentation, we show how nanostructured particle arrays with long-range order can be used to modulate an optical response through exploiting the metal-insulator transition of vanadium dioxide. Arrays of VO2 nanoparticles with long-range order were fabricated by pulsed laser deposition in an arbitrary pattern defined by focused ion-beam lithography. The interaction of light with the nanoparticles is controlled by the nanoparticle size, spacing and geometrical arrangement and by switching between the metallic and semiconducting phases of VO2. In addition to the near-infrared surface plasmon response observed in previous VO2 studies, the VO2 nanoparticle arrays exhibit size-dependent optical resonances in the visible region that likewise show an enhanced optical contrast between the semiconducting and metallic phases. The collective optical response as a function of temperature gives rise to an enhanced scattering state during the evolving phase transition, while the incoherent coupling between the nanoparticles produces an order-disorder-order transition.

  9. Quantum Optics, Diffraction Theory, and Elementary Particle Physics

    ScienceCinema

    None

    2011-10-06

    Physical optics has expanded greatly in recent years. Though it remains part of the ancestry of elementary particle physics, there are once again lessons to be learned from it. I shall discuss several of these, including some that have emerged at CERN and Brookhaven.

  10. Design and fabrication of diffractive microlens and analysis of optical characteristics

    NASA Astrophysics Data System (ADS)

    Wang, Meng; Li, Bin; Wei, Ming-yue; Zhang, Xin-yu; Xie, Chang-Sheng; Zhang, Tian-xu

    2010-10-01

    The method for designing diffractive microlens with micro-nano-scale structural features, through iterative angular spectrum algorithm, and fabricating diffractive microlens by single-step photolithography and a wet etching process, based on standard micro-nano-technology, was presented. Surface morphology testing shows that the diffractive microlens fabricated is composed of multi-step continuous relief structures with the feature height in the micrometer range, the distribution of the surface micro-nano-structures is circular symmetry, and the transition between the circular rings is smooth. A large number of fine structures with micro-nano-scale features can be clearly observed in the scanning electron microscope on the surface of the diffractive microlens. Surface roughness data tested shows that the surface roughness of fabricated diffractive microlens is in the nanometer range, which has reached the level of optical mirror. The optical aperture is in the micrometer range. The characteristics of the micro-structures on the surface and the optical aperture can be set and arranged flexibly by the iterative angular spectrum algorithm, according to the characteristics and parameters of the incident and outgoing beam. The results of optical characteristics measurement show that the diffractive microlens can focus incident red laser into a very small bright focal spot, and the phenomenon of focusing and defocusing is obvious. The analysis of beam quality shows that the intensity distribution and size of the focal-spot is in accord with pre-calculated results. The fabricated diffractive microlens indicates a very high diffraction efficiency. The experimental results demonstrate that the performances of the diffractive microlens can be further improved by modifying the design algorithm and optimizing the manufacture craft.

  11. Controllable design of super-oscillatory planar lenses for sub-diffraction-limit optical needles.

    PubMed

    Diao, Jinshuai; Yuan, Weizheng; Yu, Yiting; Zhu, Yechuan; Wu, Yan

    2016-02-01

    Sub-diffraction-limit optical needle can be created by a binary amplitude mask through tailoring the interference of diffraction beams. In this paper, a controllable design of super-oscillatory planar lenses to create sub-diffraction-limit optical needles with the tunable focal length and depth of focus (DOF) is presented. As a high-quality optical needle is influenced by various factors, we first propose a multi-objective and multi-constraint optimization model compromising all the main factors to achieve a needle with the prescribed characteristics. The optimizing procedure is self-designed using the Matlab programming language based on the genetic algorithm (GA) and fast Hankel transform algorithm. Numerical simulations show that the optical needles' properties can be controlled accurately. The optimized results are further validated by the theoretical calculation with the Rayleigh-Sommerfeld integral. The sub-diffraction-limit optical needles can be used in wide fields such as optical nanofabrication, super-resolution imaging, particle acceleration and high-density optical data storage. PMID:26906769

  12. Routing of deep-subwavelength optical beams without reflection and diffraction using infinitely anisotropic metamaterials

    NASA Astrophysics Data System (ADS)

    Catrysse, Peter B.; Fan, Shanhui

    2015-03-01

    Media that are described by extreme electromagnetic parameters, such as very large/small permittivity/permeability, have generated significant fundamental and applied interest in recent years. Notable examples include epsilon-near-zero, ultra-low refractive-index, and ultra-high refractive-index materials. Many photonic structures, such as waveguides, lenses, and photonic band gap materials, benefit greatly from the large index contrast provided by such media. In this paper, I discuss our recent work on media with infinite anisotropy, i.e., infinite permittivity (permeability) in one direction and finite in the other directions. As an illustration of the unusual optical behaviors that result from infinite anisotropy, I describe efficient light transport in deep-subwavelength apertures filled with infinitely anisotropic media. I then point out some of the opportunities that exist for controlling light at the nano-scale using infinitely anisotropic media by themselves. First, I show that a single medium with infinite anisotropy enables diffraction-free propagation of deep-subwavelength beams. Next, I demonstrate interfaces between two infinitely anisotropic media that are impedancematched for complete deep-subwavelength beams and enable reflection-free routing with zero bend radius that is entirely free from diffraction effects even when deep-subwavelength information is encoded on the beams. These behaviors indicate an unprecedented possibility to use media with infinite anisotropy to manipulate beams with deepsubwavelength features, including complete images. To illustrate physical realizability, I demonstrate a metamaterial design using existing materials in a planar geometry, which can be implemented using well-established nanofabrication techniques. This approach provides a path to deep-subwavelength routing of information-carrying beams and far-field imaging unencumbered by diffraction and reflection.

  13. Optical correlator techniques applied to robotic vision

    NASA Technical Reports Server (NTRS)

    Hine, Butler P., III; Reid, Max B.; Downie, John D.

    1991-01-01

    Vision processing is one of the most computationally intensive tasks required of an autonomous robot. The data flow from a single typical imaging sensor is roughly 60 Mbits/sec, which can easily overload current on-board processors. Optical correlator-based processing can be used to perform many of the functions required of a general robotic vision system, such as object recognition, tracking, and orientation determination, and can perform these functions fast enough to keep pace with the incoming sensor data. We describe a hybrid digital electronic/analog optical robotic vision processing system developed at Ames Research Center to test concepts and algorithms for autonomous construction, inspection, and maintenance of space-based habitats. We discuss the system architecture design and implementation, its performance characteristics, and our future plans. In particular, we compare the performance of the system to a more conventional all digital electronic system developed concurrently. The hybrid system consistently outperforms the digital electronic one in both speed and robustness.

  14. Direct-write diffracting tubular optical components using femtosecond lasers

    NASA Astrophysics Data System (ADS)

    McMillen, Ben; Bellouard, Yves

    2014-03-01

    Over the last decade, femtosecond lasers have been used extensively for the fabrication of optical elements via direct writing and in combination with chemical etching. These processes have been an enabling technology for manufacturing a variety of devices such as waveguides, fluidic channels, and mechanical components. Here, we present high quality micro-scale optical components buried inside various glass substrates such as soda-lime glass or fused silica. These components consist of high-precision, simple patterns with tubular shapes. Typical diameters range from a few microns to one hundred microns. With the aid of high-bandwidth, high acceleration flexure stages, we achieve highly symmetric pattern geometries, which are particularly important for achieving homogeneous stress distribution within the substrate. We model the optical properties of these structures using beam propagation simulation techniques and experimentally demonstrate that such components can be used as cost-effective, low-numerical aperture lenses. Additionally, we investigate their capability for studying the stress-distribution induced by the laser-affected zones and possible related densification effects.

  15. Optical Modulation of the Diffraction Efficiency in an Indoline Azobenzene/Amorphous Polycarbonate Film.

    PubMed

    Williams, G V M; Do, My T T; Middleton, A; Raymond, S G; Bhuiyan, M D H; Kay, A J

    2016-12-01

    We have made a diffraction grating in an indoline azobenzene/amorphous polycarbonate film by two-beam interference at 532 nm that periodically photodegrades the indoline azobenzene dye. Subsequent illumination of the film with 532-nm light into the trans-isomer band leads to trans-cis isomerization in the indoline azobenzene dye and results in a decrease in the trans-isomer band absorption coefficient. This causes the diffraction efficiency to decrease when probed at 655 nm. The diffraction efficiency returns to its original value when the 532-nm light is blocked by thermal relaxation from the indoline azobenzene cis-isomer to the trans-isomer. Thus, we have been able to optically modulate the diffraction efficiency in a thin film diffraction grating. PMID:27416904

  16. Optical Modulation of the Diffraction Efficiency in an Indoline Azobenzene/Amorphous Polycarbonate Film

    NASA Astrophysics Data System (ADS)

    Williams, G. V. M.; Do, My T. T.; Middleton, A.; Raymond, S. G.; Bhuiyan, M. D. H.; Kay, A. J.

    2016-07-01

    We have made a diffraction grating in an indoline azobenzene/amorphous polycarbonate film by two-beam interference at 532 nm that periodically photodegrades the indoline azobenzene dye. Subsequent illumination of the film with 532-nm light into the trans-isomer band leads to trans- cis isomerization in the indoline azobenzene dye and results in a decrease in the trans-isomer band absorption coefficient. This causes the diffraction efficiency to decrease when probed at 655 nm. The diffraction efficiency returns to its original value when the 532-nm light is blocked by thermal relaxation from the indoline azobenzene cis-isomer to the trans-isomer. Thus, we have been able to optically modulate the diffraction efficiency in a thin film diffraction grating.

  17. Development of Coherent X-ray Diffraction Apparatus with Kirkpatrick-Baez Mirror Optics

    SciTech Connect

    Takahashi, Y.; Tsutsumi, R.; Mimura, H.; Matsuyama, S.; Nishino, Y.; Ishikawa, T.; Yamauchi, K.

    2011-09-09

    To realize coherent x-ray diffraction microscopy with higher spatial resolution, it is necessary to increase the density of x-ray photons illuminated onto the sample. In this study, we developed a coherent x-ray diffraction apparatus with Kirkpatrick-Baez mirror optics. By using mirrors fabricated by elastic emission machining, a high-density coherent x-ray beam was produced. In a demonstration experiment using a silver nanocube as a sample, a high-contrast coherent x-ray diffraction pattern was observed over a wide-q range. This proves that both the density and the degree of coherence of the focused beam were high.

  18. Diffractive optics based on modulated subwavelength-domain V-ridge gratings

    NASA Astrophysics Data System (ADS)

    Bose, Gaurav; Verhoeven, Antonie; Vartiainen, Ismo; Roussey, Matthieu; Kuittinen, Markku; Tervo, Jani; Turunen, Jari

    2016-08-01

    We study the properties of reflection-type V-ridge gratings in the subwavelength domain and describe a method to realize diffractive optical elements by using such gratings as signal carriers. In particular, we utilize a coding scheme based on position modulation of a high-frequency V-ridge carrier grating. We design and demonstrate beam splitting elements using this coding scheme, electron-beam lithography, anisotropic wet etching of silicon, hot embossing of polymer, and metal deposition. These elements have the outstanding property of operating over a large spectral range from 406 to 520 nm. The measured diffraction patterns show excellent agreement with theoretical results given by rigorous diffraction theory.

  19. How optics and photonics is simply applied in agriculture?

    NASA Astrophysics Data System (ADS)

    Sumriddetchkajorn, Sarun

    2013-06-01

    This paper highlights based on author's experience how optics and photonics is applied in Thai agriculture. These include spectral imaging based systems and mobile applications that have been implemented in the last 5 years for rice, fishery, and sericulture. Brief review of optics and photonics in agriculture will also be introduced.

  20. All-optical atom surface traps implemented with one-dimensional planar diffractive microstructures.

    PubMed

    Alloschery, O; Mathevet, R; Weiner, J; Lezec, H J

    2006-12-25

    We characterize the loading, containment and optical properties of all-optical atom traps implemented by diffractive focusing with one-dimensional (1D) microstructures milled on gold films. These on-chip Fresnel lenses with focal lengths of the order of a few hundred microns produce optical-gradient-dipole traps. Cold atoms are loaded from a mirror magneto-optical trap (MMOT) centered a few hundred microns above the gold mirror surface. Details of loading optimization are reported and perspectives for future development of these structures are discussed. PMID:19532148

  1. Influence of the photopolymer properties in the fabrication of diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Gallego, Sergi; Fernández, Roberto; Márquez, Andrés.; Martínez, Francisco J.; Neipp, Cristian; Ortuño, Manuel; Francés, Jorge; Beléndez, Augusto; Pascual, Inmaculada

    2014-09-01

    A wide range of chemical compositions are possible to design photopolymers. These materials are also appealing for diffractive and holographic applications due to their capability to modulate the refractive index and/or the thickness when illuminated. Some of the most interesting applications for photopolymers are the optical data storage, security systems, surface relief photo-embossing, diffractive and refractive optical elements, holographic elements, solar concentrators, optical detectors and hybrid optoelectronic 3-D circuitry. Looking for an optimized chemical composition for each application many different photopolymers compositions may be needed enabling a variety of materials properties: materials with low or high rates of monomer diffusion, low or high values of shrinkage, long or short length of polymer chains and low or high light absorption. In parallel many models are presented in order to predict the photopolymers recording and the post exposure evolution. In this work we use one of these experimentally checked models to study the influence of the material characteristics in the final diffractive optical element recorded in the material. We study the changes in the surface relief and in the refractive index in order to understand the importance of each material property in the final diffractive optical element recorded.

  2. Education in applied and instrumental optics at the University of Helsinki

    NASA Astrophysics Data System (ADS)

    Stenman, Folke

    1997-12-01

    The teaching of applied and instrumental optics at the University of Helsinki Department of Physics originally grew out of the needs of the research group of molecular physics as a basis for the experimental work in the group. The training program starts with a one-year course for senior undergraduates and graduates comprising geometrical optics, eikonal theory, image forming components, matrix methods, optical instruments, the optics of laser beams, radiometry and photometry, ray tracing methods, optics of anisotropic media, diffraction theory, general image formation theory and Fourier optics. The course starts from fundamentals, but the mathematical level is kept adequate for serious work. Further applications are treated in courses on molecular spectroscopy, where ruled and holographic diffraction gratings (both plane and spherical), interferometric spectroscopy and imaging properties of spectral equipment are treated. Aspects of image analysis, information in optics, signal-to-noise ratio, etc. are treated in separate courses on Fourier method and digital spectral analysis. The applicability of optical techniques to various fields of physics and engineering and the analogies with them are especially brought out. Experimental and calculational and skills are stressed throughout. Computer programming is introduced as an indispensable tool for the optics practitioner, and the students are required to write programs of their own. The students gain practical experience, e.g., by working in the molecular physics group. Close cooperation is maintained with other research groups in laser physics, ultrasonics and physical chemistry. The training in optics has proved very useful, with students frequently ending up working in the industry on optics and spectroscopy problems. Parts of these courses have also been given at other universities and to engineers and scientists working in the industry.

  3. Measuring In-Plane Displacements with Variable Sensitivity Using Diffractive Optic Interferometry

    NASA Technical Reports Server (NTRS)

    Shepherd, Robert L.; Gilbert, John A.; Cole, Helen J.; Ashley, Paul R.

    1998-01-01

    This paper introduces a method called diffractive optic interferometry (DOI) which allows in-plane displacement components to be measured with variable sensitivity. DOI relies on binary optical elements fabricated as phase-type Dammann gratings which produce multiple diffraction orders of nearly equal intensity. Sensitivity is varied by combining the different wavefronts produced by a conjugate pair of these binary optical elements; a transmission element is used to produce several illumination beams while a reflective element, replicated on the surface of a specimen, provides the reference for the undeformed state. The steps taken to design and fabricate these binary optical elements are described. The specimen grating is characterized, and tested on a disk subjected to diametrical compression. Overall, the results are excellent, with experimental data agreeing to within a few percent of the theoretical predictions.

  4. Teaching applied optics at the Univ. of Minho

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F. M.

    1995-10-01

    In this communication we make a brief presentation of the branch of Applied Optics of the University of Mihno's undergraduate course of Applied Physics. The course of Applied Physics began in the year 1988/89. Previously we had just a course devoted to the formation of future physics and chemistry teachers at high school level. The Applied Physics course specialized in Optics appeared due to the growth of the physics department and due to request from the industry. The Applied Physics course has two specialization's on the field of applied optics: Optometry; and Optics and Lasers. The topics covered in the two first years of the course ar common to the two branches. On the second semester of the third year the students must choose between either one. The number of students on the Optometry branch was usually almost four times the number of Applied Optics and Lasers students. Nevertheless this tendency is rapidly changing. A short analysis of the result obtained will be presented focusing on last couple of years' advances. Presented will also be the results of an inquest made on students's opinions about the quality of the course, and their own performance and expectations.

  5. Trends in optical coherence tomography applied to medical imaging

    NASA Astrophysics Data System (ADS)

    Podoleanu, Adrian G.

    2014-01-01

    The number of publications on optical coherence tomography (OCT) continues to double every three years. Traditionally applied to imaging the eye, OCT is now being extended to fields outside ophthalmology and optometry. Widening its applicability, progress in the core engine of the technology, and impact on development of novel optical sources, make OCT a very active and rapidly evolving field. Trends in the developments of different specific devices, such as optical sources, optical configurations and signal processing will be presented. Encompassing studies on both the configurations as well as on signal processing themes, current research in Kent looks at combining spectral domain with time domain imaging for long axial range and simultaneous imaging at several depths. Results of the collaborative work of the Applied Optics Group in Kent with organisers of this conference will be presented, with reference to 3D monitoring of abfraction.

  6. Fabrication of gray-scale masks and diffractive optical elements with LDW glass

    NASA Astrophysics Data System (ADS)

    Korolkov, Victor P.; Malyshev, Anatoly I.; Poleshchuk, Alexander G.; Cherkashin, Vadim V.; Tiziani, Hans J.; Pruss, Christof; Schoder, Thomas; Westhauser, Johann; Wu, Chuck

    2001-11-01

    In the last years the application of gray-scale masks (GSM) for diffractive optics manufacturing attracts attention because of cost-effective possibility to produce a lot of diffractive elements on hard and heat-resistant thermally stable substrates. Direct laser writing of GSMs and fabrication of diffractive optical elements are effectively realized with application of LDW-glass (material for Laser Direct Write from CANYON MATERIALS, Inc). An important advantage of this material is the real-time change of transmittance in a single-step process without liquid development. It is shown that optimal transmittance range in which track width is not more than 1 micrometers is from 5-10% (transmittance of unexposed area) to 60-65% for LDW-glass type I having thinner colored layer. Power modulation and surroundings dependent peculiarities of direct laser writing on LDW-glass are discussed. Results of fabrication of diffractive optical elements using LDW-glass masks are presented. Among several types of LDW glasses studied the advantages of new GS-11 glass are elaborated. Application of GS-11 glass for GSMs allowed to fabricate blazed diffractive structures with backward slope width of 0.8 micrometers .

  7. Approach to improve beam quality of inter-satellite optical communication system based on diffractive optical elements.

    PubMed

    Tan, Liying; Yu, Jianjie; Ma, Jing; Yang, Yuqiang; Li, Mi; Jiang, Yijun; Liu, Jianfeng; Han, Qiqi

    2009-04-13

    For inter-satellite optical communication transmitter with reflective telescope of two-mirrors on axis, a large mount of the transmitted energy will be blocked by central obscuration of the secondary mirror. In this paper, a novel scheme based on diffractive optical element (DOE) is introduced to avoid it. This scheme includes one diffractive beam shaper and another diffractive phase corrector, which can diffract the obscured part of transmitted beam into the domain unobscured by the secondary mirror. The proposed approach is firstly researched with a fixed obscuration ratio of 1/4. Numerical simulation shows that the emission efficiency of new figuration is 99.99%; the beam divergence from the novel inter-satellite optical communication transmitter is unchanged; and the peak intensity of receiver plane is increased about 31% compared with the typical configuration. Then the intensy patterns of receiver plane are analyzed with various obscuration ratio, the corresponding numerical modelling reveals that the intensity patterns with various obscuration ratio are nearly identical, but the amplify of relative peak intensity is getting down with the growth of obscuration ratio. This work can improve the beam quality of inter-satellite optical communication system without affecting any other functionality. PMID:19365457

  8. Optical asymmetric watermarking using modified wavelet fusion and diffractive imaging

    NASA Astrophysics Data System (ADS)

    Mehra, Isha; Nishchal, Naveen K.

    2015-05-01

    In most of the existing image encryption algorithms the generated keys are in the form of a noise like distribution with a uniform distributed histogram. However, the noise like distribution is an apparent sign indicating the presence of the keys. If the keys are to be transferred through some communication channels, then this may lead to a security problem. This is because; the noise like features may easily catch people's attention and bring more attacks. To address this problem it is required to transfer the keys to some other meaningful images to disguise the attackers. The watermarking schemes are complementary to image encryption schemes. In most of the iterative encryption schemes, support constraints play an important role of the keys in order to decrypt the meaningful data. In this article, we have transferred the support constraints which are generated by axial translation of CCD camera using amplitude-, and phase- truncation approach, into different meaningful images. This has been done by developing modified fusion technique in wavelet transform domain. The second issue is, in case, the meaningful images are caught by the attacker then how to solve the copyright protection. To resolve this issue, watermark detection plays a crucial role. For this purpose, it is necessary to recover the original image using the retrieved watermarks/support constraints. To address this issue, four asymmetric keys have been generated corresponding to each watermarked image to retrieve the watermarks. For decryption, an iterative phase retrieval algorithm is applied to extract the plain-texts from corresponding retrieved watermarks.

  9. Design and analysis of diffractive optical elements for flattening of single modal Gaussian beams

    NASA Astrophysics Data System (ADS)

    Yin, Kewei; Huang, Zhiqiang; Lin, Wumei; Xing, Tingwen

    2012-10-01

    A design method of diffractive optical element is presented for converting a single modal Gaussian beam into a flat-top beam in the far field of the source. The design is based on geometrical method and modified Gerchberg-Saxton method. Geometrical method derives from the conservation of energy and the constant optical path length. This method could supply initial phase distribution of the modified Gerchberg-Saxton method. To find the optimization design results, the modified Gerchberg-Saxton method is important to choose the feedback factor to increase the convergent speed. In addition, tolerances and limitations of such elements result in a reduction of the diffraction efficiency and as a result of stray light. Further study indicates that deviation of the laser wavelength, incident beam, and observation plane can greatly influence flat-top beam shaping quality. On the basis of theoretical and experimental results, limitations for the application of diffractive beam shaping elements are investigated.

  10. Influence of phase delay profile on diffraction efficiency of liquid crystal optical phased array

    NASA Astrophysics Data System (ADS)

    Xu, Lin; Zhang, Jian; Wu, Li Ying

    2009-06-01

    The hardware structure and driving voltage of liquid crystal optical phased array (LCOPA) devices determine the produced phase delay characteristics. The phase delay profile influences directly the device's diffraction efficiency. In this paper, a sawtooth-shaped phase delay model of LCOPA was proposed to analyze quantitatively the influence factors of diffraction efficiency employing Fourier optics theory. Analysis results show that flyback region size is the main factor that affects diffraction efficiency. The influence extent varies with different maximum-phase-delays and grating periods. There exists an optimized curve between maximum-phase-delay and flyback region, and between maximum-phase-delay and grating period, individually. The smaller the grating period is or the larger the flyback region is, the more evident the optimization effect becomes, and the maximum increase ratio is up to 16%. Some feasible experiments were done to test theoretical analysis, and the experimental results agreed with the analysis results.

  11. Geometrical Reasoning in Wave Situations: The Case of Light Diffraction and Coherent Illumination Optical Imaging

    ERIC Educational Resources Information Center

    Maurines, Laurence

    2010-01-01

    This particular study is part of a research programme on the difficulties encountered by students when learning about wave phenomena in a three-dimensional medium in the absence or presence of obstacles. It focuses on how students reason in situations in which wave optics need to be used: diffraction of light by an aperture, imaging in the…

  12. Rejuvenation in scale-free optics and enhanced diffraction cancellation life-time.

    PubMed

    Parravicini, J; Conti, C; Agranat, A J; DelRe, E

    2012-11-19

    We demonstrate rejuvenation in scale-free optical propagation. The phenomenon is caused by the non-ergodic relaxation of the dipolar glass that mediates the photorefractive nonlinearity in compositionally-disordered lithium-enriched potassium-tantalate-niobate (KTN:Li). We implement rejuvenation to halt aging in the dipolar glass and extend the duration of beam diffraction cancellation. PMID:23187594

  13. Highly efficient acousto-optic diffraction in Sn2P2S6 crystals.

    PubMed

    Martynyuk-Lototska, I Yu; Mys, O G; Grabar, A A; Stoika, I M; Vysochanskii, Yu M; Vlokh, R O

    2008-01-01

    We have studied the acousto-optic (AO) diffraction in Sn2P2S6 crystals and found that they manifest high values of an AO figure of merit. The above crystals may therefore be used as highly efficient materials in different AO applications. PMID:18157276

  14. Nanofabrication of diffractive optics for soft X-ray and atom beam focusing

    NASA Astrophysics Data System (ADS)

    Rehbein, S.

    2003-03-01

    Nanostructuring processes are described for manufacturing diffractive optics for the condensermonochromator set-up of the transmission X-ray microscope (TXM) and for the scanning transmission X-ray microscope (STXM) at the BESSY II electron storage ring in Berlin. Furthermore, a process for manufacturing freestanding nickel zone plates for helium atom beam focusing experiments is presented.

  15. Optical diffraction by the microstructure of the wing of a moth

    NASA Astrophysics Data System (ADS)

    Brink, D. J.; Smit, J. E.; Lee, M. E.; Möller, A.

    1995-09-01

    On the wing of the moth Trichoplusia orichalcea a prominent, apparently highly reflective, golden spot can be seen. Scales from this area of the wing exhibit a regular microstructure resembling a submicrometer herringbone pattern. We show that a diffraction process from this structure is responsible for the observed optical properties, such as directionality, brightness variations, polarization, and color.

  16. Method for studying the phase function in tunable diffraction optical elements

    SciTech Connect

    Paranin, V D; Tukmakov, K N

    2014-04-28

    A method for studying the phase function in tunable diffraction optical elements is proposed, based on measurement of the transmission of interelectrode gaps. The mathematical description of the method, which is approved experimentally, is developed. The instrumental error effects are analysed. (laser applications and other topics in quantum electronics)

  17. Modified Method of Increasing of Reconstruction Quality of Diffractive Optical Elements Displayed with LC SLM

    NASA Astrophysics Data System (ADS)

    Krasnov, V. V.; Cheremkhin, P. A.; Erkin, I. Yu.; Evtikhiev, N. N.; Starikov, R. S.; Starikov, S. N.

    Modified method of increasing of reconstruction quality of diffractive optical elements (DOE) displayed with liquid crystal (LC) spatial light modulators (SLM) is presented. Method is based on optimization of DOE synthesized with conventional method by application of direct search with random trajectory method while taking into account LC SLM phase fluctuations. Reduction of synthesis error up to 88% is achieved.

  18. Optimizing diffraction efficiency for transmission holographic optical elements with HARMAN holographic materials

    NASA Astrophysics Data System (ADS)

    Smith, Steven L.; Harvey, Karen; Richardson, Martin; Blyth, Jeff

    2011-02-01

    HARMAN technology's new holographic emulsions; red sensitive and green sensitive assisted by smaller grain sizes, novel sensitization and coating technology have been shown to achieve high diffraction efficiencies and narrow band reconstruction capabilities. Authors demonstrate processing optimizations and material behavior characteristics for Transmission image Masters as well as Holographic Optical Elements (HOE's).

  19. Visible-band testbed projector with a replicated diffractive optical element.

    PubMed

    Chen, C B; Hegg, R G; Johnson, W T; King, W B; Rock, D F; Spande, R

    1999-12-01

    Raytheon has designed, fabricated, and tested a diffractive-optical-element-based (DOE-based) testbed projector for direct and indirect visual optical applications. By use of a low-cost replicated DOE surface from Rochester Photonics Corporation for color correction the projector optics bettered the modular transfer function of an equivalent commercial camera lens. The testbed demonstrates that a practical DOE-based optical system is suitable for both visual applications (e.g., head-mounted displays) and visual projection (e.g., tactical sensors). The need for and the proper application of DOE's in visual optical systems, the nature and the performance of the projector optical design, and test results are described. PMID:18324257

  20. Edge diffraction of optical-vortex beams formed by means of the fork hologram

    NASA Astrophysics Data System (ADS)

    Chernykh, Aleksey; Bekshaev, Aleksandr; Khoroshun, Anna; Mikhaylovskaya, Lidiya; Akhmerov, Aleksandr; Mohammed, Kadhim A.

    2015-11-01

    We present the experimental and numerical study of the transverse profile for a beam obtained by the screen-edge diffraction of optical-vortex (OV) Kummer beams with topological charges 1, 2 and 3, generated with the help of a "fork" hologram. The main results concern the behavior of the secondary OVs formed in the diffracted beam due to splitting of the incident multicharged OV into a set of single-charged ones. When the screen edge moves across the incident beam, OVs in every cross section of the diffracted beam describe complicated spiral-like trajectories, which distinctly manifests the screw-like nature and the energy circulation in the OV beam. At certain conditions, positions of the separate OVs as well as their mutual configuration (singular skeleton of the diffracted beam) shows high sensitivity to the screen edge dislocation with respect to the incident beam axis. This can be used for remote measurements of small displacements and deformations.

  1. Long-baseline optical intensity interferometry. Laboratory demonstration of diffraction-limited imaging

    NASA Astrophysics Data System (ADS)

    Dravins, Dainis; Lagadec, Tiphaine; Nuñez, Paul D.

    2015-08-01

    Context. A long-held vision has been to realize diffraction-limited optical aperture synthesis over kilometer baselines. This will enable imaging of stellar surfaces and their environments, and reveal interacting gas flows in binary systems. An opportunity is now opening up with the large telescope arrays primarily erected for measuring Cherenkov light in air induced by gamma rays. With suitable software, such telescopes could be electronically connected and also used for intensity interferometry. Second-order spatial coherence of light is obtained by cross correlating intensity fluctuations measured in different pairs of telescopes. With no optical links between them, the error budget is set by the electronic time resolution of a few nanoseconds. Corresponding light-travel distances are approximately one meter, making the method practically immune to atmospheric turbulence or optical imperfections, permitting both very long baselines and observing at short optical wavelengths. Aims: Previous theoretical modeling has shown that full images should be possible to retrieve from observations with such telescope arrays. This project aims at verifying diffraction-limited imaging experimentally with groups of detached and independent optical telescopes. Methods: In a large optics laboratory, artificial stars (single and double, round and elliptic) were observed by an array of small telescopes. Using high-speed photon-counting solid-state detectors and real-time electronics, intensity fluctuations were cross-correlated over up to 180 baselines between pairs of telescopes, producing coherence maps across the interferometric Fourier-transform plane. Results: These interferometric measurements were used to extract parameters about the simulated stars, and to reconstruct their two-dimensional images. As far as we are aware, these are the first diffraction-limited images obtained from an optical array only linked by electronic software, with no optical connections between the

  2. Transient x-ray diffraction and its application to materials science and x-ray optics

    SciTech Connect

    Hauer, A.A.; Kopp, R.; Cobble, J.; Kyrala, G.; Springer, R.

    1997-12-01

    Time resolved x-ray diffraction and scattering have been applied to the measurement of a wide variety of physical phenomena from chemical reactions to shock wave physics. Interest in this method has heightened in recent years with the advent of versatile, high power, pulsed x-ray sources utilizing laser plasmas, electron beams and other methods. In this article, we will describe some of the fundamentals involved in time resolved x-ray diffraction, review some of the history of its development, and describe some recent progress in the field. In this article we will emphasize the use of laser-plasmas as the x-ray source for transient diffraction.

  3. Vector fuzzy control iterative algorithm for the design of sub-wavelength diffractive optical elements for beam shaping

    NASA Astrophysics Data System (ADS)

    Lin, Yong; Hu, Jiasheng; Wu, Kenan

    2009-08-01

    The vector fuzzy control iterative algorithm (VFCIA) is proposed for the design of phase-only sub-wavelength diffractive optical elements (SWDOEs) for beam shaping. The vector diffraction model put forward by Mansuripur is applied to relate the field distributions between the SWDOE plane and the output plane. Fuzzy control theory is used to decide the constraint method for each iterative process of the algorithm. We have designed a SWDOE that transforms a circular flat-top beam to a square irradiance pattern. Computer design results show that the SWDOE designed by the VFCIA can produce better results than the vector iterative algorithm (VIA). And the finite difference time-domain method (FDTD), a rigorous electromagnetic analysis technique, is used to analyze the designed SWDOE for further confirming the validity of the proposed method.

  4. LIGHT MODULATION: Wide-aperture diffraction of unpolarised radiation in a system of two acousto-optic filters

    NASA Astrophysics Data System (ADS)

    Magdich, L. N.; Yushkov, K. B.; Voloshinov, V. B.

    2009-04-01

    Light diffraction is studied in two tandem acousto-optic cells filtering unpolarised radiation with a wide angular spectrum. It is shown that the side lobes of the ultrasonic radiation pattern of a piezoelectric transducer produce side diffraction intensity maxima at the output of the system consisting of two filters. Diffraction in paratellurite filters is studied experimentally at 1.06 μm.

  5. Analytical description of 3D optical pulse diffraction by a phase-shifted Bragg grating.

    PubMed

    Golovastikov, Nikita V; Bykov, Dmitry A; Doskolovich, Leonid L; Soifer, Victor A

    2016-08-22

    Diffraction of a three-dimensional (3D) spatiotemporal optical pulse by a phase-shifted Bragg grating (PSBG) is considered. The pulse diffraction is described in terms of signal transmission through a linear system with a transfer function determined by the reflection or transmission coefficient of the PSBG. Resonant approximations of the reflection and transmission coefficients of the PSBG as functions of the angular frequency and the in-plane component of the wave vector are obtained. Using these approximations, a hyperbolic partial differential equation (Klein-Gordon equation) describing a general class of transformations of the incident 3D pulse envelope is derived. A solution to this equation is found in the form of a convolution integral. The presented rigorous simulation results fully confirm the proposed theoretical description. The obtained results may find application in the design of new devices for spatiotemporal pulse shaping and for optical information processing and analog optical computing. PMID:27557167

  6. Signatures of spatial inversion asymmetry of an optical lattice observed in matter-wave diffraction

    NASA Astrophysics Data System (ADS)

    Thomas, C. K.; Barter, T. H.; Leung, T.-H.; Daiss, S.; Stamper-Kurn, D. M.

    2016-06-01

    The structure of a two-dimensional honeycomb optical lattice potential with small inversion asymmetry is characterized using coherent diffraction of 87Rb atoms. We demonstrate that even a small potential asymmetry, with peak-to-peak amplitude of ≤2.3 % of the overall lattice potential, can lead to pronounced inversion asymmetry in the momentum-space diffraction pattern. The observed asymmetry is explained quantitatively by considering both Kapitza-Dirac scattering in the Raman-Nath regime and also either perturbative or full-numerical treatment of the band structure of a periodic potential with a weak inversion-symmetry-breaking term. Our results have relevance for both the experimental development of coherent atom optics and the proper interpretation of time-of-flight assays of atomic materials in optical lattices.

  7. Transferring diffractive optics from research to commercial applications: Part II - size estimations for selected markets

    NASA Astrophysics Data System (ADS)

    Brunner, Robert

    2014-04-01

    In a series of two contributions, decisive business-related aspects of the current process status to transfer research results on diffractive optical elements (DOEs) into commercial solutions are discussed. In part I, the focus was on the patent landscape. Here, in part II, market estimations concerning DOEs for selected applications are presented, comprising classical spectroscopic gratings, security features on banknotes, DOEs for high-end applications, e.g., for the semiconductor manufacturing market and diffractive intra-ocular lenses. The derived market sizes are referred to the optical elements, itself, rather than to the enabled instruments. The estimated market volumes are mainly addressed to scientifically and technologically oriented optical engineers to serve as a rough classification of the commercial dimensions of DOEs in the different market segments and do not claim to be exhaustive.

  8. Signatures of spatial inversion asymmetry of an optical lattice observed in matter-wave diffraction

    NASA Astrophysics Data System (ADS)

    Thomas, Claire K.; Barter, Thomas H.; Leung, Tsz Him; Okano, Masayuki; Stamper-Kurn, Dan M.

    2016-05-01

    The structure of a two-dimensional honeycomb optical lattice potential with small inversion asymmetry is characterized using coherent diffraction of 87 Rb atoms. We demonstrate that even a small potential asymmetry, with peak-to-peak amplitude of <= 2 . 3 % of the overall lattice potential, can lead to pronounced inversion asymmetry in the momentum-space diffraction pattern. The observed asymmetry is explained quantitatively by considering both Kaptiza-Dirac scattering in the Raman-Nath regime, and also either perturbative or full-numerical treatment of the band structure of a periodic potential with a weak inversion symmetry breaking term. Our results have relevance both for the experimental development of coherent atom optics and also for the proper interpretation of time-of-flight assays of atomic materials in optical lattices. This work was supported by the NSF and the AFOSR through the MURI program.

  9. Optically controlled dense current structures driven by relativistic plasma aperture-induced diffraction

    NASA Astrophysics Data System (ADS)

    Gonzalez-Izquierdo, Bruno; Gray, Ross J.; King, Martin; Dance, Rachel J.; Wilson, Robbie; McCreadie, John; Butler, Nicholas M. H.; Capdessus, Remi; Hawkes, Steve; Green, James S.; Borghesi, Marco; Neely, David; McKenna, Paul

    2016-05-01

    The collective response of charged particles to intense fields is intrinsic to plasma accelerators and radiation sources, relativistic optics and many astrophysical phenomena. Here we show that a relativistic plasma aperture is generated in thin foils by intense laser light, resulting in the fundamental optical process of diffraction. The plasma electrons collectively respond to the resulting laser near-field diffraction pattern, producing a beam of energetic electrons with a spatial structure that can be controlled by variation of the laser pulse parameters. It is shown that static electron-beam and induced-magnetic-field structures can be made to rotate at fixed or variable angular frequencies depending on the degree of ellipticity in the laser polarization. The concept is demonstrated numerically and verified experimentally, and is an important step towards optical control of charged particle dynamics in laser-driven dense plasma sources.

  10. Evaluation of Diffraction Efficiency and Image Quality in Optical Reconstruction of Digital Fresnel Holograms

    NASA Astrophysics Data System (ADS)

    Evtikhiev, N. N.; Starikov, S. N.; Cheremkhin, P. A.; Kurbatova, E. A.

    2015-01-01

    We evaluate diffraction efficiency and image quality in the process of optical reconstruction of the digital holograms, which are displayed on spatial light modulators (SLM) with 2 and 256 brightness levels. The dependences of the above-mentioned parameters on the ratio between the intensities of the object and reference waves during recording of digital holograms are found. Numerically synthesized digital Fresnel holograms were used for modeling of the optical image retrieval. The results of the analysis were used to determine the ratios of intensities of the object and reference waves, at which the best ratios of diffraction efficiency and quality of the optically reconstructed images are achieved in the cases of using the amplitude and phase SLMs.