WorldWideScience

Sample records for polarization holographic optical

  1. Polarization holographic optical recording of a new photochromic diarylethene

    Science.gov (United States)

    Pu, Shouzhi; Miao, Wenjuan; Chen, Anyin; Cui, Shiqiang

    2008-12-01

    A new symmetrical photochromic diarylethene, 1,2-bis[2-methyl-5-(3-methoxylphenyl)-3-thienyl]perfluorocyclopentene (1a), was synthesized, and its photochromic properties were investigated. The compound exhibited good photochromism both in solution and in PMMA film with alternating irradiation by UV/VIS light, and the maxima absorption of its closed-ring isomer 1b are 582 and 599 nm, respectively. Using diarylethene 1b/PMMA film as recording medium and a He-Ne laser (633 nm) for recording and readout, four types of polarization and angular multiplexing holographic optical recording were performed perfectly. For different types of polarization recording including parallel linear polarization recording, parallel circular polarization recording, orthogonal linear polarization recording and orthogonal circular polarization recording,have been accomplished successfully. The results demonstrated that the orthogonal circular polarization recording is the best method for polarization holographic optical recording when this compound was used as recording material. With angular multiplexing recording technology, two high contrast holograms were recorded in the same place on the film with the dimension of 0.78 μm2.

  2. Temporal formation of optical anisotropy and surface relief during polarization holographic recording in polymethylmethacrylate with azobenzene side groups

    Science.gov (United States)

    Sasaki, Tomoyuki; Izawa, Masahiro; Noda, Kohei; Nishioka, Emi; Kawatsuki, Nobuhiro; Ono, Hiroshi

    2014-03-01

    The formation of polarization holographic gratings with both optical anisotropy and surface relief (SR) deformation was studied for polymethylmethacrylate with azobenzene side groups. Temporal contributions of isotropic and anisotropic phase gratings were simultaneously determined by observing transitional intensity and polarization states of the diffraction beams and characterizing by means of Jones calculus. To clarify the mechanism of SR deformation, cross sections of SR were characterized based on the optical gradient force model; experimental observations were in good agreement with the theoretical expectation. We clarified that the anisotropic phase change originating in the reorientation of the azobenzene side groups was induced immediately at the beginning of the holographic recording, while the response time of the isotropic phase change originating in the molecular migration due to the optical gradient force was relatively slow.

  3. Study the effect of dye concentration on optical history using circular polarization holographic grating in thin polymeric film

    International Nuclear Information System (INIS)

    Mohajerani, E.; Hosain Nataj, N.

    2006-01-01

    By studying the effect of dye concentration, we obtained the optimal dye concentration for recording holographic gratings. The history of circular polarization grating is also investigated. We built polarization holographic grating with more than 2 weeks history. By using a mask in front of pump beam, different pictures could be built up in the film.

  4. Holographic optical security systems

    Science.gov (United States)

    Fagan, William F.

    1990-06-01

    One of the most successful applications of Holography,in recent years,has been its use as an optical security technique.Indeed the general public's awareness of holograms has been greatly enhanced by the incorporation of holographic elements into the VISA and MASTERCHARGE credit cards.Optical techniques related to Holography,are also being used to protect the currencies of several countries against the counterfeiter. The mass production of high quality holographic images is by no means a trivial task as a considerable degree of expertise is required together with an optical laboratory and embossing machinery.This paper will present an overview of the principal holographic and related optical techniques used for security purposes.Worldwide, over thirty companies are involved in the production of security elements utilising holographic and related optical technologies.Counterfeiting of many products is a major criminal activity with severe consequences not only for the manufacturer but for the public in general as defective automobile parts,aircraft components,and pharmaceutical products, to cite only a few of the more prominent examples,have at one time or another been illegally copied.

  5. Atomic force and optical near-field microscopic investigations of polarization holographic gratings in a liquid crystalline azobenzene side-chain polyester

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Holme, N.C.R.; Hvilsted, S.

    1996-01-01

    Atomic force and scanning near-field optical microscopic investigations have been carried out on a polarization holographic grating recorded in an azobenzene side-chain Liquid crystalline polyester. It has been found that immediately following laser irradiation, a topographic surface grating...

  6. Holographic Optical Data Storage

    Science.gov (United States)

    Timucin, Dogan A.; Downie, John D.; Norvig, Peter (Technical Monitor)

    2000-01-01

    Although the basic idea may be traced back to the earlier X-ray diffraction studies of Sir W. L. Bragg, the holographic method as we know it was invented by D. Gabor in 1948 as a two-step lensless imaging technique to enhance the resolution of electron microscopy, for which he received the 1971 Nobel Prize in physics. The distinctive feature of holography is the recording of the object phase variations that carry the depth information, which is lost in conventional photography where only the intensity (= squared amplitude) distribution of an object is captured. Since all photosensitive media necessarily respond to the intensity incident upon them, an ingenious way had to be found to convert object phase into intensity variations, and Gabor achieved this by introducing a coherent reference wave along with the object wave during exposure. Gabor's in-line recording scheme, however, required the object in question to be largely transmissive, and could provide only marginal image quality due to unwanted terms simultaneously reconstructed along with the desired wavefront. Further handicapped by the lack of a strong coherent light source, optical holography thus seemed fated to remain just another scientific curiosity, until the field was revolutionized in the early 1960s by some major breakthroughs: the proposition and demonstration of the laser principle, the introduction of off-axis holography, and the invention of volume holography. Consequently, the remainder of that decade saw an exponential growth in research on theory, practice, and applications of holography. Today, holography not only boasts a wide variety of scientific and technical applications (e.g., holographic interferometry for strain, vibration, and flow analysis, microscopy and high-resolution imagery, imaging through distorting media, optical interconnects, holographic optical elements, optical neural networks, three-dimensional displays, data storage, etc.), but has become a prominent am advertising

  7. HOMES - Holographic Optical Method for Exoplanet Spectroscopy

    Data.gov (United States)

    National Aeronautics and Space Administration — HOMES (Holographic Optical Method for Exoplanet Spectroscopy) is a space telescope that employs a double dispersion architecture, using a holographic optical element...

  8. Rewritable azobenzene polyester for polarization holographic data storage

    DEFF Research Database (Denmark)

    Kerekes, A; Sajti, Sz.; Loerincz, Emoeke

    2000-01-01

    Optical storage properties of thin azobenzene side-chain polyester films were examined by polarization holographic measurements. The new amorphous polyester film is the candidate material for the purpose of rewritable holographic memory system. Temporal formation of anisotropic and topographic...... gratings was studied in case of films with and without a hard protective layer. We showed that the dominant contribution to the diffraction efficiency comes from the anisotropy in case of expositions below 1 sec even for high incident intensity. The usage of the same wavelength for writing, reading...

  9. Color multiplexing using directional holographic gratings and linear polarization

    International Nuclear Information System (INIS)

    Lugo, L I; Rodriguez, A; Ramirez, G; Guel, S; Nunez, O F

    2011-01-01

    We propose a system of multiplexing and de-multiplexing, which uses a holographic diffraction grating to compel modulated light of different colors to be sent through an optical fiber. Diffraction gratings were fabricated specifically to pick the desired direction in which we wanted the light of different wavelengths to impinge the optic fiber, and also to be separated at the output. It was been found that the system preserves the polarization of light, which give us a one more freedom degree, allowing us to process twice the original information amount.

  10. Realization of an optical interferometer based on holographic optics ...

    Indian Academy of Sciences (India)

    The paper describes a simple and cost effective method for the realization of an optical interferometer based on holographic optics, which use minimal bulk optical components. The optical arrangement in the proposed method involves a very simple alignment procedure and inexpensive holographic recording material is ...

  11. Polarization digital holographic microscopy using low-cost liquid crystal polarization rotators

    Science.gov (United States)

    Dovhaliuk, Rostyslav Yu

    2018-02-01

    Polarization imaging methods are actively used to study anisotropic objects. A number of methods and systems, such as imaging polarimeters, were proposed to measure the state of polarization of light that passed through the object. Digital holographic and interferometric approaches can be used to quantitatively measure both amplitude and phase of a wavefront. Using polarization modulation optics, the measurement capabilities of such interference-based systems can be extended to measure polarization-dependent parameters, such as phase retardation. Different kinds of polarization rotators can be used to alternate the polarization of a reference beam. Liquid crystals are used in a rapidly increasing number of different optoelectronic devices. Twisted nematic liquid crystals are widely used as amplitude modulators in electronic displays and light valves or shutter glass. Such devices are of particular interest for polarization imaging, as they can be used as polarization rotators, and due to large-scale manufacturing have relatively low cost. A simple Mach-Zehnder polarized holographic setup that uses modified shutter glass as a polarization rotator is demonstrated. The suggested approach is experimentally validated by measuring retardation of quarter-wave film.

  12. Polarization holographic recording in Disperse Red1 doped polyurethane polymer film

    Energy Technology Data Exchange (ETDEWEB)

    Aleksejeva, J; Gerbreders, A; Gertners, U; Reinfelde, M; Teteris, J, E-mail: aleksejeva.jelena@gmail.com [Institute of Solid State Physics, University of Latvia, Kengaraga street 8, Riga (Latvia)

    2011-06-23

    In this report holographic recording of polarisation and surface relief gratings in Disperse Red 1 (DR1) doped polyurethane polymer films was studied. In this material DR1 is chemically bounded to polyurethane polymer main chain. Polarization holographic recording was performed by two orthogonal circularly polarized 532 nm laser beams. Photoinduced birefringence is a precondition for polarization holograms recording, therefore a detailed study of a photoinduced birefringence and changes of optical properties was performed. The lasers with wavelengths of 375nm, 448nm, 532 nm and 632.8 nm were used as pumping beam for sample excitation. The photoinduced birefringence {Delta}n was measured at 532 nm and 632.8 nm wavelengths. The photoinduced birefringence dependence on the pumping beam wavelength and intensity was investigated. Surface relief grating (SRG) formation was observed during polarization holographic recording process. A profile of SRG was studied by AFM. A relationship between SRG formation and photoinduced birefringence has been discussed.

  13. Photopolymer for Optical Holography and Holographic Interferometry

    Czech Academy of Sciences Publication Activity Database

    Květoň, M.; Lédl, Vít; Havránek, A.; Fiala, P.

    2010-01-01

    Roč. 295, č. 1 (2010), s. 107-113 ISSN 1022-1360 Institutional research plan: CEZ:AV0Z20430508 Keywords : holographic interferometry * holography * photopolymerization * recording material * refractive index Subject RIV: BH - Optics, Masers, Lasers http://onlinelibrary.wiley.com/doi/10.1002/masy.200900093/pdf

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

    Science.gov (United States)

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

    2015-01-01

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

  15. Optical studies in the holographic ground station

    Science.gov (United States)

    Workman, Gary L.

    1991-01-01

    The Holographic Group System (HGS) Facility in rooms 22 & 123, Building 4708 has been developed to provide for ground based research in determining pre-flight parameters and analyzing the results from space experiments. The University of Alabama, Huntsville (UAH) has researched the analysis aspects of the HGS and reports their findings here. Some of the results presented here also occur in the Facility Operating Procedure (FOP), which contains instructions for power up, operation, and powerdown of the Fluid Experiment System (FES) Holographic Ground System (HGS) Test Facility for the purpose of optically recording fluid and/or crystal behavior in a test article during ground based testing through the construction of holograms and recording of videotape. The alignment of the optical bench components, holographic reconstruction and and microscopy alignment sections were also included in the document for continuity even though they are not used until after optical recording of the test article) setup of support subsystems and the Automated Holography System (AHS) computer. The HGS provides optical recording and monitoring during GCEL runs or development testing of potential FES flight hardware or software. This recording/monitoring can be via 70mm holographic film, standard videotape, or digitized images on computer disk. All optical bench functions necessary to construct holograms will be under the control of the AHS personal computer (PC). These include type of exposure, time intervals between exposures, exposure length, film frame identification, film advancement, film platen evacuation and repressurization, light source diffuser introduction, and control of realtime video monitoring. The completed sequence of hologram types (single exposure, diffuse double exposure, etc.) and their time of occurrence can be displayed, printed, or stored on floppy disk posttest for the user.

  16. Polarization and switching properties of holographic polymer-dispersed liquid-crystal gratings. I. Theoretical model

    Science.gov (United States)

    Sutherland, Richard L.

    2002-12-01

    Polarization properties and electro-optical switching behavior of holographic polymer-dispersed liquid-crystal (HPDLC) reflection and transmission gratings are studied. A theoretical model is developed that combines anisotropic coupled-wave theory with an elongated liquid-crystal-droplet switching model and includes the effects of a statistical orientational distribution of droplet-symmetry axes. Angle- and polarization-dependent switching behaviors of HPDLC gratings are elucidated, and the effects on dynamic range are described. A new type of electro-optical switching not seen in ordinary polymer-dispersed liquid crystals, to the best of the author's knowledge, is presented and given a physical interpretation. The model provides valuable insight to the physics of these gratings and can be applied to the design of HPDLC holographic optical elements.

  17. Circularly polarized antennas for active holographic imaging through barriers

    Science.gov (United States)

    McMakin, Douglas L [Richland, WA; Severtsen, Ronald H [Richland, WA; Lechelt, Wayne M [West Richland, WA; Prince, James M [Kennewick, WA

    2011-07-26

    Circularly-polarized antennas and their methods of use for active holographic imaging through barriers. The antennas are dielectrically loaded to optimally match the dielectric constant of the barrier through which images are to be produced. The dielectric loading helps to remove barrier-front surface reflections and to couple electromagnetic energy into the barrier.

  18. LMM Holographic Optical Tweezers (HOT) Module, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to expand the capabilities of the LMM for colloidal and other research by developing a holographic optical tweezers (HOT) module, allowing solid-state...

  19. Polarization Optics in Telecommunications

    CERN Document Server

    Damask, Jay N

    2005-01-01

    The strong investments into optical telecommunications in the late 1990s resulted in a wealth of new research, techniques, component designs, and understanding of polarization effects in fiber. Polarization Optics in Telecommunications brings together recent advances in the field to create a standard, practical reference for component designers and optical fiber communication engineers. Beginning with a sound foundation in electromagnetism, the author offers a dissertation of the spin-vector formalism of polarization and the interaction of light with media. Applications discussed include optical isolators, optical circulators, fiber collimators, and a variety of applied waveplate and prism combinations. Also included in an extended discussion of polarization-mode dispersion (PMD) and polarization-dependent loss (PDL), their representation, behavior, statistical properties, and measurement. This book draws extensively from the technical and patent literature and is an up-to-date reference for researchers and c...

  20. Optically intraconnected computer employing dynamically reconfigurable holographic optical element

    Science.gov (United States)

    Bergman, Larry A. (Inventor)

    1992-01-01

    An optically intraconnected computer and a reconfigurable holographic optical element employed therein. The basic computer comprises a memory for holding a sequence of instructions to be executed; logic for accessing the instructions in sequence; logic for determining for each the instruction the function to be performed and the effective address thereof; a plurality of individual elements on a common support substrate optimized to perform certain logical sequences employed in executing the instructions; and, element selection logic connected to the logic determining the function to be performed for each the instruction for determining the class of each function and for causing the instruction to be executed by those the elements which perform those associated the logical sequences affecting the instruction execution in an optimum manner. In the optically intraconnected version, the element selection logic is adapted for transmitting and switching signals to the elements optically.

  1. Temporal characteristics of polarization holographic gratings formed in a photosensitive polymeric film containing N-benzylideneaniline derivative side groups

    Science.gov (United States)

    Sasaki, Tomoyuki; Shoho, Takashi; Noda, Kohei; Kawatsuki, Nobuhiro; Ono, Hiroshi

    2014-04-01

    A polarization holographic grating was recorded in a transparent thin film formed from polymethacrylate with N-benzylideneaniline (NBA) derivative side groups. We measured the real time diffraction properties. The data were analyzed based on a theoretical model that accounted for the distribution of optical anisotropy caused by molecular reorientation as well as for surface relief (SR) deformation caused by molecular motion. Optical anisotropy rapidly increased and then slowly decreased, with increasing recording time. This phenomenon was described based on photoisomerization and photocleavage reactions of the NBA side groups. SR deformation was also induced in the film by polarization holographic recording, without any subsequent processes. The photoinduced optical anisotropy and SR deformation were retained after the recording was turned off.

  2. Temporal characteristics of polarization holographic gratings formed in a photosensitive polymeric film containing N-benzylideneaniline derivative side groups

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Tomoyuki, E-mail: sasaki-tomoy@vos.nagaokaut.ac.jp; Shoho, Takashi; Noda, Kohei; Ono, Hiroshi [Department of Electrical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Kawatsuki, Nobuhiro [Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan)

    2014-04-21

    A polarization holographic grating was recorded in a transparent thin film formed from polymethacrylate with N-benzylideneaniline (NBA) derivative side groups. We measured the real time diffraction properties. The data were analyzed based on a theoretical model that accounted for the distribution of optical anisotropy caused by molecular reorientation as well as for surface relief (SR) deformation caused by molecular motion. Optical anisotropy rapidly increased and then slowly decreased, with increasing recording time. This phenomenon was described based on photoisomerization and photocleavage reactions of the NBA side groups. SR deformation was also induced in the film by polarization holographic recording, without any subsequent processes. The photoinduced optical anisotropy and SR deformation were retained after the recording was turned off.

  3. Holographic Optical Elements Recorded in Silver Halide Sensitized Gelatin Emulsions. Part I. Transmission Holographic Optical Elements

    Science.gov (United States)

    Kim, Jong Man; Choi, Byung So; Kim, Sun Il; Kim, Jong Min; Bjelkhagen, Hans I.; Phillips, Nicholas J.

    2001-02-01

    Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOE s). The drawback of DCG is its low sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra-high-resolution silver halide emulsions. An optimized processing technique for transmission HOE s recorded in these materials is introduced. Diffraction efficiencies over 90% can be obtained for transmissive diffraction gratings. Understanding the importance of the selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOE s.

  4. Polarization-Independent Electrically Tunable Holographic Polymer Dispersed Liquid Crystals Grating Doped with Chiral Molecules

    Directory of Open Access Journals (Sweden)

    Hui LI

    2017-08-01

    Full Text Available This study proposes a holographic grating made of polymer dispersed liquid crystal (PDLC, with a small amount of chiral molecules doped into PDLC material. The major advantage of this grating is that it is independent of light polarization. This characteristic was verified by applying the interference beam intensity of a He-Cd laser at 150 mW/cm2, with an incidence angle between the two interference beams of 24°, for an irradiation curing duration of 120 s. The observed periodic structure of the grating is consistent with the theoretical value. As chiral molecules are doped, nematic-LC experiences a phase-change in the grating. However, the electro-optical features are only slightly affected. This proposed grating has greatly potential in 3D imaging because of its polarization-independent feature.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.16312

  5. Analysis of the optical parameters of phase holographic gratings

    Directory of Open Access Journals (Sweden)

    Є.О. Тихонов

    2008-03-01

    Full Text Available  Suitability of 2- wave approximation of the coupled waves theory tor description of holographic phase gratings recorded on photopolymer compound ФПК-488 is proved. Using the basic formulas of the theory, main grating optical parameters - a depth of modulation and finished thickness are not measured immediately are determined.

  6. Page Oriented Holographic Memories And Optical Pattern Recognition

    Science.gov (United States)

    Caulfield, H. J.

    1987-08-01

    In the twenty-two years since VanderLugt's introduction of holographic matched filtering, the intensive research carried out throughout the world has led to no applications in complex environment. This leads one to the suspicion that the VanderLugt filter technique is insufficiently complex to handle truly complex problems. Therefore, it is of great interest to increase the complexity of the VanderLugt filtering operation. We introduce here an approach to the real time filter assembly: use of page oriented holographic memories and optically addressed SLMs to achieve intelligent and fast reprogramming of the filters using a 10 4 to 10 6 stored pattern base.

  7. Reusable holographic velocimetry system based on polarization multiplexing in Bacteriorhodopsin

    NARCIS (Netherlands)

    Koek, W.D.; Chan, V.S.S.; Ooms, T.A.; Bhattacharya, N.; Westerweel, J.; Braat, J.J.M.

    2005-01-01

    We present a novel holographic particle image velocimetry (HPIV) system using a reversible holographic material as the recording medium. In HPIV the three-dimensional flow field throughout a volume is detected by adding small tracer particles to a normally transparent medium. By recording the

  8. Holographic Optical Elements Recorded in Silver Halide Sensitized Gelatin Emulsions. Part 2. Reflection Holographic Optical Elements

    Science.gov (United States)

    Kim, Jong Man; Choi, Byung So; Choi, Yoon Sun; Kim, Jong Min; Bjelkhagen, Hans I.; Phillips, Nicholas J.

    2002-03-01

    Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOEs). The drawback of DCG is its low energetic sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra-fine-grain silver halide (AgHal) emulsions. In particular, high spatial-frequency fringes associated with HOEs of the reflection type are difficult to construct when SHSG processing methods are employed. Therefore an optimized processing technique for reflection HOEs recorded in the new AgHal materials is introduced. Diffraction efficiencies over 90% can be obtained repeatably for reflection diffraction gratings. Understanding the importance of a selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOEs, also including high-quality display holograms of the reflection type in both monochrome and full color.

  9. Optical neutron polarizers

    International Nuclear Information System (INIS)

    Hayter, J.B.

    1990-01-01

    A neutron wave will be refracted by an appropriately varying potential. Optical neutron polarizers use spatially varying, spin- dependent potentials to refract neutrons of opposite spin states into different directions, so that an unpolarized beam will be split into two beams of complementary polarization by such a device. This paper will concentrate on two methods of producing spin-dependent potentials which are particularly well-suited to polarizing cold neutron beams, namely thin-film structures and field-gradient techniques. Thin-film optical devices, such as supermirror multilayer structures, are usually designed to deviate only one spin-state, so that they offer the possibility of making insertion (transmission) polarizers. Very good supermirrors may now be designed and fabricated, but it is not always straightforward to design mirror-based devices which are useful in real (divergent beam) applications, and some practical configurations will be discussed. Field-gradient devices, which are usually based on multipolar magnets, have tended to be too expensive for general use, but this may change with new developments in superconductivity. Dipolar and hexapolar configurations will be considered, with emphasis on the focusing characteristics of the latter. 21 refs., 7 figs

  10. Polarized light and optical measurement

    CERN Document Server

    Clarke, D N; Ter Haar, D

    2013-01-01

    Polarized Light and Optical Measurement is a five-chapter book that begins with a self-consistent conceptual picture of the phenomenon of polarization. Chapter 2 describes a number of interactions of light and matter used in devising optical elements in polarization studies. Specific optical elements are given in Chapter 3. The last two chapters explore the measurement of the state of polarization and the various roles played in optical instrumentation by polarization and polarization-sensitive elements. This book will provide useful information in this field of interest for research workers,

  11. Biphotonic holographic gratings in azobenzene polyesters: Surface relief phenomena and polarization effects

    DEFF Research Database (Denmark)

    Sánchez, C.; Alcalá, R.; Hvilsted, Søren

    2000-01-01

    Biphotonic holographic gratings have been recorded in a side-chain azobenzene liquid crystalline polyester using a blue incoherent source and a He-Ne laser. Intensity gratings and the appearance of surface relief have been observed when two linearly polarized beams from a He-Ne laser are made...... to interfere on a film illuminated with blue light. Polarized holographic gratings are also created with two orthogonally circularly polarized He-Ne beams. All these gratings are stable in darkness but can be erased with blue light. (C) 2000 American Institute of Physics....

  12. Holographic spectrum-splitting optical systems for solar photovoltaics

    Science.gov (United States)

    Zhang, Deming

    Solar energy is the most abundant source of renewable energy available. The relatively high cost prevents solar photovoltaic (PV) from replacing fossil fuel on a larger scale. In solar PV power generation the cost is reduced with more efficient PV technologies. In this dissertation, methods to improve PV conversion efficiency with holographic optical components are discussed. The tandem multiple-junction approach has achieved very high conversion efficiency. However it is impossible to manufacture tandem PV cells at a low cost due to stringent fabrication standards and limited material types that satisfy lattice compatibility. Current produced by the tandem multi-junction PV cell is limited by the lowest junction due to series connection. Spectrum-splitting is a lateral multi-junction concept that is free of lattice and current matching constraints. Each PV cell can be optimized towards full absorption of a spectral band with tailored light-trapping schemes. Holographic optical components are designed to achieve spectrum-splitting PV energy conversion. The incident solar spectrum is separated onto multiple PV cells that are matched to the corresponding spectral band. Holographic spectrum-splitting can take advantage of existing and future low-cost technologies that produces high efficiency thin-film solar cells. Spectrum-splitting optical systems are designed and analyzed with both transmission and reflection holographic optical components. Prototype holograms are fabricated and high optical efficiency is achieved. Light-trapping in PV cells increases the effective optical path-length in the semiconductor material leading to improved absorption and conversion efficiency. It has been shown that the effective optical path length can be increased by a factor of 4n2 using diffusive surfaces. Ultra-light-trapping can be achieved with optical filters that limit the escape angle of the diffused light. Holographic reflection gratings have been shown to act as angle

  13. Accelerated optical holographic recording using bis-DNO

    DEFF Research Database (Denmark)

    Rasmussen, Palle H.; Ramanujam, P.S.; Hvilsted, Søren

    1999-01-01

    The design, synthesis and optical holographic recording properties of bis-DNO are reported. Bis-DNO is composed of two identical azobenzene oligoornithine segments (DNO) connected via a dipeptide linker. The two segments were assembled in a parallel fashion at the two amino groups of the dipeptid...... linker by Merrifield synthesis. Surprisingly, the response time of films of bis-DNOs was found to be much faster than that of their linear counterparts. (C) 1999 Elsevier Science Ltd. All rights reserved....

  14. Read-only high accuracy volume holographic optical correlator

    Science.gov (United States)

    Zhao, Tian; Li, Jingming; Cao, Liangcai; He, Qingsheng; Jin, Guofan

    2011-10-01

    A read-only volume holographic correlator (VHC) is proposed. After the recording of all of the correlation database pages by angular multiplexing, a stand-alone read-only high accuracy VHC will be separated from the VHC recording facilities which include the high-power laser and the angular multiplexing system. The stand-alone VHC has its own low power readout laser and very compact and simple structure. Since there are two lasers that are employed for recording and readout, respectively, the optical alignment tolerance of the laser illumination on the SLM is very sensitive. The twodimensional angular tolerance is analyzed based on the theoretical model of the volume holographic correlator. The experimental demonstration of the proposed read-only VHC is introduced and discussed.

  15. Liquid crystals for holographic optical data storage

    DEFF Research Database (Denmark)

    Matharu, Avtar; Jeeva, S.; Ramanujam, P.S.

    2007-01-01

    to the information storage demands of the 21st century is detailed. Holography is a small subset of the much larger field of optical data storage and similarly, the diversity of materials used for optical data storage is enormous. The theory of polarisation holography which produces holograms of constant intensity...

  16. System and carrier for optical images and holographic information recording

    International Nuclear Information System (INIS)

    Andries, A.; Bivol, V.; Iovu, M

    2002-01-01

    The invention relates to the semiconducting silverless photography, in particular to the technique for optical information recording and may be used in microphotography for manifacture of microfiches, microfilms, storage disks, i the multiplication and copying technique, in holography, in micro- and optoelectronics, cinematography etc. The system for optical images and holographic information recording includes an optical exposure system, an information carrier , containing a dielectric substrate with the first electrode, a photosensitive element and the second electrode, arranged in consecutive order, a constant and impulse voltage source, a means for climbing and movement of the information carrier, a control unit for connection of the voltage source to the electroconducting strate, a personal computer, connected to the control unit of the recording modes ,to the exposure system and the information carrier, an electrooptical transparency, connected to the computer by means of the matching unit. The carrier for optical images and holographic information recording contains a dielectric substrate, a photosensitive element formed of a layer of the vitreous chalcogenic semiconductor and a layer of the crystalline or amorphous semiconductor, forming a heterojunction, the photosensitive element is arranged between two electrodes , one of which is made transparent , in such case rge layer of the vitreous chalcogenic semiconductor comes into contact with the superior transparent electrode, subjected to exposure

  17. Pulsed recording of anisotropy and holographic polarization gratings in azo-polymethacrylates with different molecular architectures

    DEFF Research Database (Denmark)

    Forcén, Patricia; Oriol, Luis; Alcala, Rafael

    2008-01-01

    Recording of anisotropy and holographic polarization gratings using 532 nm, 4 ns light pulses has been carried out in thin films of polymers with the same azobenzene content (20 wt %) and different molecular architectures. Random and block copolymers comprising azobenzene and methylmethacrylate (...

  18. Holographic analysis of dispersive pupils in space--time optics

    International Nuclear Information System (INIS)

    Calatroni, J.; Vienot, J.C.

    1981-01-01

    Extension of space--time optics to objects whose transparency is a function of the temporal frequency v = c/lambda is examined. Considering the effects of such stationary pupils on white light waves, they are called temporal pupils. It is shown that simultaneous encoding both in the space and time frequency domains is required to record pupil parameters. The space-time impulse response and transfer functions are calculated for a dispersive nonabsorbent material. An experimental method providing holographic recording of the dispersion curve of any transparent material is presented

  19. Compact holographic memory and its application to optical pattern recognition

    Science.gov (United States)

    Chao, Tien-Hsin; Reyes, George F.; Zhou, Hanying

    2001-03-01

    JPL is developing a high-density, nonvolatile Compact Holographic Data Storage (CHDS) system to enable large- capacity, high-speed, low power consumption, and read/write of data for commercial and space applications. This CHDS system consists of laser diodes, photorefractive crystal, spatial light modulator, photodetector array, and I/O electronic interface. In operation, pages of information would be recorded and retrieved with random access and high- speed. In this paper, recent technology progress in developing this CHDS at JPL will be presented. The recent applications of the CHDS to optical pattern recognition, as a high-density, high transfer rate memory bank will also be discussed.

  20. Holographic analysis of dispersive pupils in space--time optics

    Energy Technology Data Exchange (ETDEWEB)

    Calatroni, J.; Vienot, J.C.

    1981-06-01

    Extension of space--time optics to objects whose transparency is a function of the temporal frequency v = c/lambda is examined. Considering the effects of such stationary pupils on white light waves, they are called temporal pupils. It is shown that simultaneous encoding both in the space and time frequency domains is required to record pupil parameters. The space-time impulse response and transfer functions are calculated for a dispersive nonabsorbent material. An experimental method providing holographic recording of the dispersion curve of any transparent material is presented.

  1. Thin combiner optics utilizing volume holographic optical elements (vHOEs) using Bayfol HX photopolymer film

    Science.gov (United States)

    Bruder, Friedrich-Karl; Fäcke, Thomas; Hagen, Rainer; Hansen, Sven; Manecke, Christel; Orselli, Enrico; Rewitz, Christian; Rölle, Thomas; Walze, Günther

    2017-06-01

    The main function of any augmented reality system is to seamlessly merge the real world perception of a viewer with computer generated images and information. Besides real-time head-tracking and room-scanning capabilities the combiner optics, which optically merge the natural with the artificial visual information, represent a key component for those systems. Various types of combiner optics are known to the industry, all with their specific advantages and disadvantages. Beside the well-established solutions based on refractive optics or surface gratings, volume Holographic Optical Elements (vHOEs) are a very attractive alternative in this field. The unique characteristics of these diffractive grating structures - being lightweight, thin, flat and invisible in Off Bragg conditions - make them perfectly suitable for their use in integrated and compact combiners. For any consumer application it is paramount to build unobtrusive and lightweight augmented reality displays, for which those volume holographic combiners are ideally suited. Due to processing challenges of (historic) holographic recording materials mass production of vHOE holographic combiners was not possible. Therefore vHOE based combiners found use in military applications only by now. The new Bayfol® HX instant developing holographic photopolymer film provides an ideal technology platform to optimize the performance of vHOEs in a wide range of applications. Bayfol® HX provides full color capability and adjustable diffraction efficiency as well as an unprecedented optical clarity when compared to classical holographic recording materials like silver halide emulsions (AgHX) or dichromated gelatin (DCG). Bayfol® HX film is available in industrial scale and quality. Its properties can be tailored for various diffractive performances and integration methods. Bayfol® HX film is easy to process without any need for chemical or thermal development steps, offering simplified contact-copy mass production

  2. Diffused holographic information storage and retrieval using photorefractive optical materials

    Science.gov (United States)

    McMillen, Deanna Kay

    Holography offers a tremendous opportunity for dense information storage, theoretically one bit per cubic wavelength of material volume, with rapid retrieval, of up to thousands of pages of information simultaneously. However, many factors prevent the theoretical storage limit from being reached, including dynamic range problems and imperfections in recording materials. This research explores new ways of moving closer to practical holographic information storage and retrieval by altering the recording materials, in this case, photorefractive crystals, and by increasing the current storage capacity while improving the information retrieved. As an experimental example of the techniques developed, the information retrieved is the correlation peak from an optical recognition architecture, but the materials and methods developed are applicable to many other holographic information storage systems. Optical correlators can potentially solve any signal or image recognition problem. Military surveillance, fingerprint identification for law enforcement or employee identification, and video games are but a few examples of applications. A major obstacle keeping optical correlators from being universally accepted is the lack of a high quality, thick (high capacity) holographic recording material that operates with red or infrared wavelengths which are available from inexpensive diode lasers. This research addresses the problems from two positions: find a better material for use with diode lasers, and reduce the requirements placed on the material while maintaining an efficient and effective system. This research found that the solutions are new dopants introduced into photorefractive lithium niobate to improve wavelength sensitivities and the use of a novel inexpensive diffuser that reduces the dynamic range and optical element quality requirements (which reduces the cost) while improving performance. A uniquely doped set of 12 lithium niobate crystals was specified and

  3. Diffraction from polarization holographic gratings with surface relief in side-chain azobenzene polyesters

    DEFF Research Database (Denmark)

    Naydenova, I; Nikolova, L; Todorov, T

    1998-01-01

    We investigate the polarization properties of holographic gratings in side-chain azobenzene polyesters in which an anisotropic grating that is due to photoinduced linear and circular birefringence is recorded in the volume of the material and a relief grating appears on the surface. A theoretical...... model is proposed to explain the experimental results, making it possible to understand the influence of the different photoinduced effects. It is shown that at low intensity the polarization properties of the diffraction at these gratings are determined by the interaction of the linear and circular...... photobirefringences, and at larger intensity the influence of the surface relief dominates the effect of the circular anisotropy. Owing to the high recording efficiency of the polyesters, the +/-1-order diffracted waves change the polarization interference pattern during the holographic recording, resulting...

  4. Fourier transform digital holographic adaptive optics imaging system

    Science.gov (United States)

    Liu, Changgeng; Yu, Xiao; Kim, Myung K.

    2013-01-01

    A Fourier transform digital holographic adaptive optics imaging system and its basic principles are proposed. The CCD is put at the exact Fourier transform plane of the pupil of the eye lens. The spherical curvature introduced by the optics except the eye lens itself is eliminated. The CCD is also at image plane of the target. The point-spread function of the system is directly recorded, making it easier to determine the correct guide-star hologram. Also, the light signal will be stronger at the CCD, especially for phase-aberration sensing. Numerical propagation is avoided. The sensor aperture has nothing to do with the resolution and the possibility of using low coherence or incoherent illumination is opened. The system becomes more efficient and flexible. Although it is intended for ophthalmic use, it also shows potential application in microscopy. The robustness and feasibility of this compact system are demonstrated by simulations and experiments using scattering objects. PMID:23262541

  5. Carrier for registration of optical images and holographic information

    International Nuclear Information System (INIS)

    Andries, A.; Bivol, V.; Iovu, M.

    2000-01-01

    The invention relates to the field of registration of optical information including the holographic one and may be used in the holography, cinematography, micro- and optical electronics, computer engineering. Summary of the invention consists in, that in the carrier containing a dielectric substrate on which there are placed in sequence the first electrode, photoinjection substrate, registration substrate of the chalcogenide vitreous semiconductor and the second electrode, the photoinjection substrate is fabricated of the monocrystalline germanium of the n-type conductivity and the relation of the registration substrate conductivity, during illumination to the photoinjection substrate conductivity in darkness is 0,001. The technical result consists in increasing the carrier photosensibility and in diffraction effectiveness of the information registered on the carrier

  6. Measurement of spatial refractive index distributions of fusion spliced optical fibers by digital holographic microtomography

    Science.gov (United States)

    Pan, Feng; Deng, Yating; Ma, Xichao; Xiao, Wen

    2017-11-01

    Digital holographic microtomography is improved and applied to the measurements of three-dimensional refractive index distributions of fusion spliced optical fibers. Tomographic images are reconstructed from full-angle phase projection images obtained with a setup-rotation approach, in which the laser source, the optical system and the image sensor are arranged on an optical breadboard and synchronously rotated around the fixed object. For retrieving high-quality tomographic images, a numerical method is proposed to compensate the unwanted movements of the object in the lateral, axial and vertical directions during rotation. The compensation is implemented on the two-dimensional phase images instead of the sinogram. The experimental results exhibit distinctly the internal structures of fusion splices between a single-mode fiber and other fibers, including a multi-mode fiber, a panda polarization maintaining fiber, a bow-tie polarization maintaining fiber and a photonic crystal fiber. In particular, the internal structure distortion in the fusion areas can be intuitively observed, such as the expansion of the stress zones of polarization maintaining fibers, the collapse of the air holes of photonic crystal fibers, etc.

  7. Rewritable three-dimensional holographic data storage via optical forces

    Energy Technology Data Exchange (ETDEWEB)

    Yetisen, Ali K., E-mail: ayetisen@mgh.harvard.edu [Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, Massachusetts 02139 (United States); Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Montelongo, Yunuen [Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Butt, Haider [Nanotechnology Laboratory, School of Engineering Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2016-08-08

    The development of nanostructures that can be reversibly arranged and assembled into 3D patterns may enable optical tunability. However, current dynamic recording materials such as photorefractive polymers cannot be used to store information permanently while also retaining configurability. Here, we describe the synthesis and optimization of a silver nanoparticle doped poly(2-hydroxyethyl methacrylate-co-methacrylic acid) recording medium for reversibly recording 3D holograms. We theoretically and experimentally demonstrate organizing nanoparticles into 3D assemblies in the recording medium using optical forces produced by the gradients of standing waves. The nanoparticles in the recording medium are organized by multiple nanosecond laser pulses to produce reconfigurable slanted multilayer structures. We demonstrate the capability of producing rewritable optical elements such as multilayer Bragg diffraction gratings, 1D photonic crystals, and 3D multiplexed optical gratings. We also show that 3D virtual holograms can be reversibly recorded. This recording strategy may have applications in reconfigurable optical elements, data storage devices, and dynamic holographic displays.

  8. Optical processing of holographic lateral shear interferograms recorded by displacing an object

    International Nuclear Information System (INIS)

    Lyalikov, A M

    2008-01-01

    A new approach is considered which is used in holographic lateral shear interferometry and allows the combination of the displacement of a phase object under study during the recording of holographic interferograms with the optical processing of displaced and optically conjugate holographic interferograms. Depending on the method of optical processing of such a pair of holographic interferograms, several aberration-free interference patterns are observed, which reflect with different sensitivities variations in the light wave phase caused by the phase object. Due to the lateral shear, which is equal to or exceeds the linear size of the object, the interference patterns of the object are identical to interference patterns obtained in a two-beam, reference-wave interferometer. The possibility of using this method to control optical inhomogeneities in active crystals in solid-state lasers is studied experimentally. (interferometry)

  9. Optical Security System Based on the Biometrics Using Holographic Storage Technique with a Simple Data Format

    Science.gov (United States)

    Jun, An Won

    2006-01-01

    We implement a first practical holographic security system using electrical biometrics that combines optical encryption and digital holographic memory technologies. Optical information for identification includes a picture of face, a name, and a fingerprint, which has been spatially multiplexed by random phase mask used for a decryption key. For decryption in our biometric security system, a bit-error-detection method that compares the digital bit of live fingerprint with of fingerprint information extracted from hologram is used.

  10. Holographic Moire, An Optical Tool For The Determination Of Displacements, Strains, Contours, And Slopes Of Surfaces

    Science.gov (United States)

    Sciammarella, Cesar A.

    1982-06-01

    In conventional holographic interferometry, the observed fringe patterns are determined by the object displacement and deformation, and by the illumination and observation configurations. The obtained information may not be in the most convenient form for further data processing. To overcome this problem, and to create new possibilities, holographic fringe patterns can be changed by modifying the optical setup. As a result of these modifications, well-known procedures of the moire method can be applied to holographic interferometry. Components of displacement and components of the strain tensor can be isolated and measured separately. Surface contours and slopes can also be determined.

  11. Polarization splitter and polarization rotator designs based on transformation optics.

    Science.gov (United States)

    Kwon, Do-Hoon; Werner, Douglas H

    2008-11-10

    The transformation optics technique is employed in this paper to design two optical devices - a two-dimensional polarization splitter and a three-dimensional polarization rotator for propagating beams. The polarization splitter translates the TM- and the TE-polarized components of an incident beam in opposite directions (i.e., shifted up or shifted down). The polarization rotator rotates the polarization state of an incoming beam by an arbitrary angle. Both optical devices are reflectionless at the entry and exit interfaces. Design details and full-wave simulation results are provided.

  12. Hyperon polarization in heavy-ion collisions and holographic gravitational anomaly

    Science.gov (United States)

    Baznat, Mircea; Gudima, Konstantin; Sorin, Alexander; Teryaev, Oleg

    2018-04-01

    We study the energy dependence of global polarization of Λ hyperons in peripheral Au-Au collisions. We combine the calculation of vorticity and strange chemical potential in the framework of the kinetic quark-gluon-string model with the anomalous mechanism related to the axial vortical effect. We pay special attention to the temperature-dependent contribution related to the holographic gravitational anomaly and find that the preliminary data from the BNL Relativistic Heavy Ion Collider are compatible with its suppression discovered earlier in lattice calculations.

  13. Implementation of a digital optical matrix-vector multiplier using a holographic look-up table and residue arithmetic

    Science.gov (United States)

    Habiby, Sarry F.

    1987-01-01

    The design and implementation of a digital (numerical) optical matrix-vector multiplier are presented. The objective is to demonstrate the operation of an optical processor designed to minimize computation time in performing a practical computing application. This is done by using the large array of processing elements in a Hughes liquid crystal light valve, and relying on the residue arithmetic representation, a holographic optical memory, and position coded optical look-up tables. In the design, all operations are performed in effectively one light valve response time regardless of matrix size. The features of the design allowing fast computation include the residue arithmetic representation, the mapping approach to computation, and the holographic memory. In addition, other features of the work include a practical light valve configuration for efficient polarization control, a model for recording multiple exposures in silver halides with equal reconstruction efficiency, and using light from an optical fiber for a reference beam source in constructing the hologram. The design can be extended to implement larger matrix arrays without increasing computation time.

  14. Optical tractor Bessel polarized beams

    International Nuclear Information System (INIS)

    Mitri, F.G.; Li, R.X.; Guo, L.X.; Ding, C.Y.

    2017-01-01

    Axial and transverse radiation force cross-sections of optical tractor Bessel polarized beams are theoretically investigated for a dielectric sphere with particular emphasis on the beam topological charge (or order), half-cone angle and polarization. The angular spectrum decomposition method (ASDM) is used to derive the non-paraxial electromagnetic (EM) field components of the Bessel beams. The multipole expansion method using vector spherical harmonics is utilized and appropriate beam-shape coefficients are derived in order to compute the radiation force cross-sections. The analysis has no limitation to a particular range of frequencies such that the Rayleigh, Mie or geometrical optics regimes can all be considered effectively using the present rigorous formalism. The focus of this investigation is to identify some of the tractor beam conditions so as to achieve retrograde motion of a dielectric sphere located arbitrarily in space. Numerical computations for the axial and transverse radiation force cross-sections are presented for linear, right-circular, radial, azimuthal and mixed polarizations of the individual plane waves forming the Bessel beams of zeroth- and first-order (with positive or negative helicity), respectively. As the sphere shifts off the beam's axis, the axial pulling (tractor) force is weakened. Moreover, the transverse radiation force cross-section field changes with the sphere's size factor ka (where k is the wavenumber and a is the sphere radius). Both stable and unstable equilibrium regions around the beam's axis are found, depending on the choice of ka and the half-cone angle α_0. These results are particularly important in the development of emergent technologies for the photophoretic assembly of optically-engineered (meta)materials with designed properties using optical tractor (vortex) beams, particle manipulation, levitation and positioning, and other applications. - Highlights: • Optical tractor Bessel polarized beams are

  15. Optical tractor Bessel polarized beams

    Science.gov (United States)

    Mitri, F. G.; Li, R. X.; Guo, L. X.; Ding, C. Y.

    2017-01-01

    Axial and transverse radiation force cross-sections of optical tractor Bessel polarized beams are theoretically investigated for a dielectric sphere with particular emphasis on the beam topological charge (or order), half-cone angle and polarization. The angular spectrum decomposition method (ASDM) is used to derive the non-paraxial electromagnetic (EM) field components of the Bessel beams. The multipole expansion method using vector spherical harmonics is utilized and appropriate beam-shape coefficients are derived in order to compute the radiation force cross-sections. The analysis has no limitation to a particular range of frequencies such that the Rayleigh, Mie or geometrical optics regimes can all be considered effectively using the present rigorous formalism. The focus of this investigation is to identify some of the tractor beam conditions so as to achieve retrograde motion of a dielectric sphere located arbitrarily in space. Numerical computations for the axial and transverse radiation force cross-sections are presented for linear, right-circular, radial, azimuthal and mixed polarizations of the individual plane waves forming the Bessel beams of zeroth- and first-order (with positive or negative helicity), respectively. As the sphere shifts off the beam's axis, the axial pulling (tractor) force is weakened. Moreover, the transverse radiation force cross-section field changes with the sphere's size factor ka (where k is the wavenumber and a is the sphere radius). Both stable and unstable equilibrium regions around the beam's axis are found, depending on the choice of ka and the half-cone angle α0. These results are particularly important in the development of emergent technologies for the photophoretic assembly of optically-engineered (meta)materials with designed properties using optical tractor (vortex) beams, particle manipulation, levitation and positioning, and other applications.

  16. Optical superimposed vortex beams generated by integrated holographic plates with blazed grating

    Science.gov (United States)

    Zhang, Xue-Dong; Su, Ya-Hui; Ni, Jin-Cheng; Wang, Zhong-Yu; Wang, Yu-Long; Wang, Chao-Wei; Ren, Fei-Fei; Zhang, Zhen; Fan, Hua; Zhang, Wei-Jie; Li, Guo-Qiang; Hu, Yan-Lei; Li, Jia-Wen; Wu, Dong; Chu, Jia-Ru

    2017-08-01

    In this paper, we demonstrate that the superposition of two vortex beams with controlled topological charges can be realized by integrating two holographic plates with blazed grating. First, the holographic plate with blazed grating was designed and fabricated by laser direct writing for generating well-separated vortex beam. Then, the relationship between the periods of blazed grating and the discrete angles of vortex beams was systemically investigated. Finally, through setting the discrete angle and different revolving direction of the holographic plates, the composite fork-shaped field was realized by the superposition of two vortex beams in a particular position. The topological charges of composite fork-shaped field (l = 1, 0, 3, and 4) depend on the topological charges of compositional vortex beams, which are well agreed with the theoretical simulation. The method opens up a wide range of opportunities and possibilities for applying in optical communication, optical manipulations, and photonic integrated circuits.

  17. Optical polarization: background and camouflage

    Science.gov (United States)

    Škerlind, Christina; Hallberg, Tomas; Eriksson, Johan; Kariis, Hans; Bergström, David

    2017-10-01

    Polarimetric imaging sensors in the electro-optical region, already military and commercially available in both the visual and infrared, show enhanced capabilities for advanced target detection and recognition. The capabilities arise due to the ability to discriminate between man-made and natural background surfaces using the polarization information of light. In the development of materials for signature management in the visible and infrared wavelength regions, different criteria need to be met to fulfil the requirements for a good camouflage against modern sensors. In conventional camouflage design, the aimed design of the surface properties of an object is to spectrally match or adapt it to a background and thereby minimizing the contrast given by a specific threat sensor. Examples will be shown from measurements of some relevant materials and how they in different ways affect the polarimetric signature. Dimensioning properties relevant in an optical camouflage from a polarimetric perspective, such as degree of polarization, the viewing or incident angle, and amount of diffuse reflection, mainly in the infrared region, will be discussed.

  18. Optically pumped polarized H- ion source

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1986-01-01

    The current status and future prospects for the optically pumped polarized H - ion source are discussed. At the present time H - ion currents of 60 μA and with a polarization of 65% have been produced. The ion current and polarization can be increased significantly if the optically pumped Na charge exchange target density and polarization can be increased. Studies of wall surfaces that permit many bounces before depolarizing the Na electron spin and studies of radiation trapping in optically pumped Na indicate that the Na target density and polarization can be increased substantially. 27 refs., 6 figs., 2 tabs

  19. HoloHands: games console interface for controlling holographic optical manipulation

    Science.gov (United States)

    McDonald, C.; McPherson, M.; McDougall, C.; McGloin, D.

    2013-03-01

    The increasing number of applications for holographic manipulation techniques has sparked the development of more accessible control interfaces. Here, we describe a holographic optical tweezers experiment which is controlled by gestures that are detected by a Microsoft Kinect. We demonstrate that this technique can be used to calibrate the tweezers using the Stokes drag method and compare this to automated calibrations. We also show that multiple particle manipulation can be handled. This is a promising new line of research for gesture-based control which could find applications in a wide variety of experimental situations.

  20. HoloHands: games console interface for controlling holographic optical manipulation

    International Nuclear Information System (INIS)

    McDonald, C; McPherson, M; McDougall, C; McGloin, D

    2013-01-01

    The increasing number of applications for holographic manipulation techniques has sparked the development of more accessible control interfaces. Here, we describe a holographic optical tweezers experiment which is controlled by gestures that are detected by a Microsoft Kinect. We demonstrate that this technique can be used to calibrate the tweezers using the Stokes drag method and compare this to automated calibrations. We also show that multiple particle manipulation can be handled. This is a promising new line of research for gesture-based control which could find applications in a wide variety of experimental situations. (paper)

  1. Acoustical holographic recording with coherent optical read-out and image processing

    Science.gov (United States)

    Liu, H. K.

    1980-10-01

    New acoustic holographic wave memory devices have been designed for real-time in-situ recording applications. The basic operating principles of these devices and experimental results through the use of some of the prototypes of the devices are presented. Recording media used in the device include thermoplastic resin, Crisco vegetable oil, and Wilson corn oil. In addition, nonlinear coherent optical image processing techniques including equidensitometry, A-D conversion, and pseudo-color, all based on the new contact screen technique, are discussed with regard to the enhancement of the normally poor-resolved acoustical holographic images.

  2. Pump-induced optical distortions in disk amplifier modules: holographic and interferometric measurements

    International Nuclear Information System (INIS)

    Linford, G.J.; Chau, H.H.; Glaze, J.A.; Layne, C.B.; Rainer, F.

    1975-01-01

    Interferometric measurements have been made of the optical distortions induced in laser disk amplifiers during the flashlamp pumping pulse. Both conventional interferometric methods and the techniques of double exposure holographic interferometry were used to identify four major sources of pump-induced optical distortions: subsonic intrusion of hot gas (traced to leakage of atmospheric oxygen into the amplifier), microexplosions of dust particles, thermally induced optical distortions in the glass disks, and gaseous optical distortion effects caused by turbulent flow of the purging nitrogen gas supply used within the laser amplifier head. Methods for reducing or eliminating the effects of each of these optical distortions are described

  3. Integrated optical circuit comprising a polarization convertor

    NARCIS (Netherlands)

    1998-01-01

    An integrated optical circuit includes a first device and a second device, which devices are connected by a polarization convertor. The polarization convertor includes a curved section of a waveguide, integrated in the optical circuit. The curved section may have several differently curved

  4. New optical architecture for holographic data storage system compatible with Blu-ray Disc™ system

    Science.gov (United States)

    Shimada, Ken-ichi; Ide, Tatsuro; Shimano, Takeshi; Anderson, Ken; Curtis, Kevin

    2014-02-01

    A new optical architecture for holographic data storage system which is compatible with a Blu-ray Disc™ (BD) system is proposed. In the architecture, both signal and reference beams pass through a single objective lens with numerical aperture (NA) 0.85 for realizing angularly multiplexed recording. The geometry of the architecture brings a high affinity with an optical architecture in the BD system because the objective lens can be placed parallel to a holographic medium. Through the comparison of experimental results with theory, the validity of the optical architecture was verified and demonstrated that the conventional objective lens motion technique in the BD system is available for angularly multiplexed recording. The test-bed composed of a blue laser system and an objective lens of the NA 0.85 was designed. The feasibility of its compatibility with BD is examined through the designed test-bed.

  5. Holographic sol-gel monoliths: optical properties and application for humidity sensing

    Science.gov (United States)

    Ilatovskii, Daniil A.; Milichko, Valentin; Vinogradov, Alexander V.; Vinogradov, Vladimir V.

    2018-05-01

    Sol-gel monoliths based on SiO2, TiO2 and ZrO2 with holographic colourful diffraction on their surfaces were obtained via a sol-gel synthesis and soft lithography combined method. The production was carried out without any additional equipment at near room temperature and atmospheric pressure. The accurately replicated wavy structure with nanoscale size of material particles yields holographic effect and its visibility strongly depends on refractive index (RI) of materials. Addition of multi-walled carbon nanotubes (MWCNTs) in systems increases their RI and lends absorbing properties due to extremely high light absorption constant. Further prospective and intriguing applications based on the most successful samples, MWCNTs-doped titania, were investigated as reversible optical humidity sensor. Owing to such property as reversible resuspension of TiO2 nanoparticles while interacting with water, it was proved that holographic xerogels can repeatedly act as humidity sensors. Materials which can be applied as humidity sensors in dependence on holographic response were discovered for the first time.

  6. Holographic sol–gel monoliths: optical properties and application for humidity sensing

    Science.gov (United States)

    Milichko, Valentin; Vinogradov, Alexander V.; Vinogradov, Vladimir V.

    2018-01-01

    Sol–gel monoliths based on SiO2, TiO2 and ZrO2 with holographic colourful diffraction on their surfaces were obtained via a sol–gel synthesis and soft lithography combined method. The production was carried out without any additional equipment at near room temperature and atmospheric pressure. The accurately replicated wavy structure with nanoscale size of material particles yields holographic effect and its visibility strongly depends on refractive index (RI) of materials. Addition of multi-walled carbon nanotubes (MWCNTs) in systems increases their RI and lends absorbing properties due to extremely high light absorption constant. Further prospective and intriguing applications based on the most successful samples, MWCNTs-doped titania, were investigated as reversible optical humidity sensor. Owing to such property as reversible resuspension of TiO2 nanoparticles while interacting with water, it was proved that holographic xerogels can repeatedly act as humidity sensors. Materials which can be applied as humidity sensors in dependence on holographic response were discovered for the first time.

  7. The holographic optical micro-manipulation system based on counter-propagating beams

    Czech Academy of Sciences Publication Activity Database

    Čižmár, T.; Brzobohatý, Oto; Dholakia, K.; Zemánek, Pavel

    2011-01-01

    Roč. 8, č. 1 (2011), s. 50-56 ISSN 1612-2011 R&D Projects: GA ČR GA202/09/0348; GA MŠk(CZ) LC06007; GA MŠk OC08034; GA MŠk ED0017/01/01 Grant - others:EC(XE) COST MP0604 Institutional research plan: CEZ:AV0Z20650511 Keywords : holographic optical trapping * dual beam trap * spatial light modulator * optical rotator Subject RIV: BH - Optics, Masers, Lasers Impact factor: 9.970, year: 2011

  8. Cascaded holographic polymer reflection grating filters for optical-code-division multiple-access applications.

    Science.gov (United States)

    Kostuk, Raymond K; Maeda, Wendi; Chen, Chia-Hung; Djordjevic, Ivan; Vasic, Bane

    2005-12-10

    We evaluate the use of edge-illuminated holographic Bragg filters formed in phenanthrenequinone-doped poly(methyl methacrylate) for optical-code-division multiple-access (OCDMA) coding and decoding applications. Experimental cascaded Bragg filters are formed to select two different wavelengths with a fixed distance between the gratings and are directly coupled to a fiber-measurement system. The configuration and tolerances of the cascaded gratings are shown to be practical for time-wavelength OCDMA applications.

  9. Optical pumping production of spin polarized hydrogen

    International Nuclear Information System (INIS)

    Knize, R.J.; Happer, W.; Cecchi, J.L.

    1984-01-01

    There has been much interest recently in the production of large quantities of spin polarized hydrogen in various fields including controlled fusion, quantum fluids, high energy, and nuclear physics. One promising method for the development of large quantities of spin polarized hydrogen is the utilization of optical pumping with a laser. Optical pumping is a process where photon angular momentum is converted into electron and nuclear spin. The advent of tunable CW dye lasers (approx. 1 watt) allow the production of greater than 10 18 polarized atoms/sec. We have begun a program at Princeton to investigate the physics and technology of using optical pumping to produce large quantities of spin polarized hydrogen. Initial experiments have been done in small closed glass cells. Eventually, a flowing system, open target, or polarized ion source could be constructed

  10. Implementation of a fast digital optical matrix-vector multiplier using a holographic look-up table and residue arithmetic

    Science.gov (United States)

    Habiby, Sarry F.; Collins, Stuart A., Jr.

    1987-01-01

    The design and implementation of a digital (numerical) optical matrix-vector multiplier are presented. A Hughes liquid crystal light valve, the residue arithmetic representation, and a holographic optical memory are used to construct position coded optical look-up tables. All operations are performed in effectively one light valve response time with a potential for a high information density.

  11. The optics of secondary polarized proton beams

    International Nuclear Information System (INIS)

    Carey, D.C.

    1990-05-01

    Polarized protons can be produced by the parity-violating decay of either lambda or sigma hyperons. A secondary bema of polarized protons can then be produced without the difficult procedure of accelerating polarized protons. The preservation of the polarization while the protons are being transmitted to a final focus places stringent limitations on the optics of the beam line. The equations of motion of a polarized particle in a magnetic field have been solved to first order for quadrupole and dipole magnets. The lowest order terms indicate that the polarization vector will be restored to its original direction upon passage through a magnetic system if the momentum vector is unaltered. Higher-order terms may be derived by an expansion in commutators of the rotation matrix and its longitudinal derivative. The higher-order polarization rotation terms then arise from the non-commutivity of the rotation matrices by large angles in three-dimensional space. 5 refs., 3 figs

  12. Compact holographic optical neural network system for real-time pattern recognition

    Science.gov (United States)

    Lu, Taiwei; Mintzer, David T.; Kostrzewski, Andrew A.; Lin, Freddie S.

    1996-08-01

    One of the important characteristics of artificial neural networks is their capability for massive interconnection and parallel processing. Recently, specialized electronic neural network processors and VLSI neural chips have been introduced in the commercial market. The number of parallel channels they can handle is limited because of the limited parallel interconnections that can be implemented with 1D electronic wires. High-resolution pattern recognition problems can require a large number of neurons for parallel processing of an image. This paper describes a holographic optical neural network (HONN) that is based on high- resolution volume holographic materials and is capable of performing massive 3D parallel interconnection of tens of thousands of neurons. A HONN with more than 16,000 neurons packaged in an attache case has been developed. Rotation- shift-scale-invariant pattern recognition operations have been demonstrated with this system. System parameters such as the signal-to-noise ratio, dynamic range, and processing speed are discussed.

  13. Polarized light in optics and spectroscopy

    CERN Document Server

    Kliger, David S

    1990-01-01

    This comprehensive introduction to polarized light provides students and researchers with the background and the specialized knowledge needed to fully utilize polarized light. It provides a basic introduction to the interaction of light with matter for those unfamiliar with photochemistry and photophysics. An in-depth discussion of polarizing optics is also given. Different analytical techniques are introduced and compared and introductions to the use of polarized light in various forms of spectroscopy are provided.Key Features* Starts at a basic level and develops tools for resear

  14. Polarization Nonlinear Optics of Quadratically Nonlinear Azopolymers

    International Nuclear Information System (INIS)

    Konorov, S.O.; Akimov, D.A.; Ivanov, A.A.; Petrov, A.N.; Alfimov, M.V.; Yakimanskii, A.V.; Smirnov, N.N.; Ivanova, V.N.; Kudryavtsev, V.V.; Podshivalov, A.A.; Sokolova, I.M.; Zheltikov, A.M.

    2005-01-01

    The polarization properties of second harmonic and sum-frequency signals generated by femtosecond laser pulses in films of polymers containing covalent groups of an azobenzothiazole chromophore polarized by an external electric field are investigated. It is shown that the methods of polarization nonlinear optics make it possible to determine the structure of oriented molecular dipoles and reveal important properties of the motion of collectivized πelectrons in organic molecules with strong optical nonlinearities. The polarization measurements show that the tensor of quadratic nonlinear optical susceptibility of chromophore fragments oriented by an external field in macromolecules of the noted azopolymers has a degenerate form. This is indicative of a predominantly one-dimensional character of motion of collectivized π electrons along an extended group of atoms in such molecules

  15. Modeling optical and UV polarization of AGNs. IV. Polarization timing

    Science.gov (United States)

    Rojas Lobos, P. A.; Goosmann, R. W.; Marin, F.; Savić, D.

    2018-03-01

    Context. Optical observations cannot resolve the structure of active galactic nuclei (AGN), and a unified model for AGN was inferred mostly from indirect methods, such as spectroscopy and variability studies. Optical reverberation mapping allowed us to constrain the spatial dimension of the broad emission line region and thereby to measure the mass of supermassive black holes. Recently, reverberation was also applied to the polarized signal emerging from different AGN components. In principle, this should allow us to measure the spatial dimensions of the sub-parsec reprocessing media. Aim. We conduct numerical modeling of polarization reverberation and provide theoretical predictions for the polarization time lag induced by different AGN components. The model parameters are adjusted to the observational appearance of the Seyfert 1 galaxy NGC 4151. Methods: We modeled scattering-induced polarization and tested different geometries for the circumnuclear dust component. Our tests included the effects of clumpiness and different dust prescriptions. To further extend the model, we also explored the effects of additional ionized winds stretched along the polar direction, and of an equatorial scattering ring that is responsible for the polarization angle observed in pole-on AGN. The simulations were run using a time-dependent version of the STOKES code. Results: Our modeling confirms the previously found polarization characteristics as a function of the observer`s viewing angle. When the dust adopts a flared-disk geometry, the lags reveal a clear difference between type 1 and type 2 AGN. This distinction is less clear for a torus geometry where the time lag is more sensitive to the geometry and optical depth of the inner surface layers of the funnel. The presence of a scattering equatorial ring and ionized outflows increased the recorded polarization time lags, and the polar outflows smooths out dependence on viewing angle, especially for the higher optical depth of the

  16. Wave optics modeling of real-time holographic wavefront compensation systems using OSSim

    Science.gov (United States)

    Carbon, Margarita A.; Guthals, Dennis M.; Logan, Jerry D.

    2005-08-01

    OSSim (Optical System Simulation) is a wave-optics, time-domain simulation toolbox with both optical and data processing components developed for adaptive optics (AO) systems. Diffractive wavefront control elements have recently been added that accurately model optically and electrically addressed spatial light modulators as real time holographic (RTH) devices in diffractive wavefront control systems. The developed RTH toolbox has found multiple applications for a variety of Boeing programs in solving problems of AO system analysis and design. Several complex diffractive wavefront control systems have been modeled for compensation of static and dynamic aberrations such as imperfect segmented primary mirrors and atmospheric and boundary layer turbulence. The results of OSSim simulations of RTH wavefront compensation show very good agreement with available experimental data.

  17. Uses of laser optical pumping to produce polarized ion beams

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1983-01-01

    Laser optical pumping can be used to produce polarized alkali atom beams or polarized alkali vapor targets. Polarized alkali atom beams can be converted into polarized alkali ion beams, and polarized alkali vapor targets can be used to produce polarized H - or 3 He - ion beams. In this paper the authors discuss how the polarized alkali atom beams and polarized alkali vapor targets are used to produce polarized ion beams with emphasis on the production of polarized negative ion beams

  18. Lithographically-Scribed Planar Holographic Optical CDMA Devices and Systems

    National Research Council Canada - National Science Library

    Mossberg, Thomas

    2007-01-01

    .... The present Phase II effort has harnessed new fabrication tools to perfect disruptive HBR-based multiplexer products for DoD avionics, optical communications systems computer data communications and local area networks...

  19. Optically variable threads and polarization effects

    Science.gov (United States)

    Kretschmar, Friedrich; Burchard, Theodor; Heim, Manfred

    2006-02-01

    Based on common criteria for efficient security elements for banknotes the set-up of a state-of-the-art holographic security thread is described - as first representative of window embedded OVD. We continue with new colour-shifting OVD-threads - based on physical vapour deposition thin-film and liquid crystal technology. These three then form the family of optically variable threads following the same set of requirements for efficiency, durability, service to all authentication levels and economics. In addition to this set of OVD threads we introduce how liquid crystal based phase retarding layer can be used to install new authentication channels for the public use up-to machine authentication. Also we show the perspective how those development can be used to install similar sets of OVD families of foil elements on banknotes.

  20. Dynamic measurements and simulations of airborne picolitre-droplet coalescence in holographic optical tweezers

    International Nuclear Information System (INIS)

    Bzdek, Bryan R.; Reid, Jonathan P.; Collard, Liam; Sprittles, James E.; Hudson, Andrew J.

    2016-01-01

    We report studies of the coalescence of pairs of picolitre aerosol droplets manipulated with holographic optical tweezers, probing the shape relaxation dynamics following coalescence by simultaneously monitoring the intensity of elastic backscattered light (EBL) from the trapping laser beam (time resolution on the order of 100 ns) while recording high frame rate camera images (time resolution <10 μs). The goals of this work are to: resolve the dynamics of droplet coalescence in holographic optical traps; assign the origin of key features in the time-dependent EBL intensity; and validate the use of the EBL alone to precisely determine droplet surface tension and viscosity. For low viscosity droplets, two sequential processes are evident: binary coalescence first results from the overlap of the optical traps on the time scale of microseconds followed by the recapture of the composite droplet in an optical trap on the time scale of milliseconds. As droplet viscosity increases, the relaxation in droplet shape eventually occurs on the same time scale as recapture, resulting in a convoluted evolution of the EBL intensity that inhibits quantitative determination of the relaxation time scale. Droplet coalescence was simulated using a computational framework to validate both experimental approaches. The results indicate that time-dependent monitoring of droplet shape from the EBL intensity allows for robust determination of properties such as surface tension and viscosity. Finally, the potential of high frame rate imaging to examine the coalescence of dissimilar viscosity droplets is discussed.

  1. Dynamic measurements and simulations of airborne picolitre-droplet coalescence in holographic optical tweezers

    Energy Technology Data Exchange (ETDEWEB)

    Bzdek, Bryan R.; Reid, Jonathan P., E-mail: j.p.reid@bristol.ac.uk [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Collard, Liam [Department of Mathematics, University of Leicester, Leicester LE1 7RH (United Kingdom); Sprittles, James E. [Mathematics Institute, University of Warwick, Coventry CV4 7AL (United Kingdom); Hudson, Andrew J. [Department of Chemistry, University of Leicester, Leicester LE1 7RH (United Kingdom)

    2016-08-07

    We report studies of the coalescence of pairs of picolitre aerosol droplets manipulated with holographic optical tweezers, probing the shape relaxation dynamics following coalescence by simultaneously monitoring the intensity of elastic backscattered light (EBL) from the trapping laser beam (time resolution on the order of 100 ns) while recording high frame rate camera images (time resolution <10 μs). The goals of this work are to: resolve the dynamics of droplet coalescence in holographic optical traps; assign the origin of key features in the time-dependent EBL intensity; and validate the use of the EBL alone to precisely determine droplet surface tension and viscosity. For low viscosity droplets, two sequential processes are evident: binary coalescence first results from the overlap of the optical traps on the time scale of microseconds followed by the recapture of the composite droplet in an optical trap on the time scale of milliseconds. As droplet viscosity increases, the relaxation in droplet shape eventually occurs on the same time scale as recapture, resulting in a convoluted evolution of the EBL intensity that inhibits quantitative determination of the relaxation time scale. Droplet coalescence was simulated using a computational framework to validate both experimental approaches. The results indicate that time-dependent monitoring of droplet shape from the EBL intensity allows for robust determination of properties such as surface tension and viscosity. Finally, the potential of high frame rate imaging to examine the coalescence of dissimilar viscosity droplets is discussed.

  2. Order and chaos in polarized nonlinear optics

    International Nuclear Information System (INIS)

    Holm, D.D.

    1990-01-01

    Methods for investigating temporal complexity in Hamiltonian systems are applied to the dynamics of a polarized optical laser beam propagating as a travelling wave in a medium with cubically nonlinear polarizability (i.e., a Kerr medium). The theory of Hamiltonian systems with symmetry is used to study the geometry of phase space for the optical problem, transforming from C 2 to S 2 x (J,θ), where (J,θ) is a symplectic action-angle pair. The bifurcations of the phase portraits of the Hamiltonian motion on S 2 are classified and shown graphically. These bifurcations create various saddle connections on S 2 as either J (the beam intensity), or the optical parameters of the medium are varied. After this bifurcation analysis, the Melnikov method is used to demonstrate analytically that the saddle connections break and intersect transversely in a Poincare map under spatially periodic perturbations of the optical parameters of the medium. These transverse intersections in the Poincare map imply intermittent polarization switching with extreme sensitivity to initial conditions characterized by a Smale horseshoe construction for the travelling waves of a polarized optical laser pulse. The resulting chaotic behavior in the form of sensitive dependence on initial conditions may have implications for the control and predictability of nonlinear optical polarization switching in birefringent media. 19 refs., 2 figs., 1 tab

  3. Optics. Observation of optical polarization Möbius strips.

    Science.gov (United States)

    Bauer, Thomas; Banzer, Peter; Karimi, Ebrahim; Orlov, Sergej; Rubano, Andrea; Marrucci, Lorenzo; Santamato, Enrico; Boyd, Robert W; Leuchs, Gerd

    2015-02-27

    Möbius strips are three-dimensional geometrical structures, fascinating for their peculiar property of being surfaces with only one "side"—or, more technically, being "nonorientable" surfaces. Despite being easily realized artificially, the spontaneous emergence of these structures in nature is exceedingly rare. Here, we generate Möbius strips of optical polarization by tightly focusing the light beam emerging from a q-plate, a liquid crystal device that modifies the polarization of light in a space-variant manner. Using a recently developed method for the three-dimensional nanotomography of optical vector fields, we fully reconstruct the light polarization structure in the focal region, confirming the appearance of Möbius polarization structures. The preparation of such structured light modes may be important for complex light beam engineering and optical micro- and nanofabrication. Copyright © 2015, American Association for the Advancement of Science.

  4. Holographic optical tweezers for object manipulations at an air-liquid surface.

    Science.gov (United States)

    Jesacher, Alexander; Fürhapter, Severin; Maurer, Christian; Bernet, Stefan; Ritsch-Marte, Monika

    2006-06-26

    We investigate holographic optical tweezers manipulating micro-beads at a suspended air-liquid interface. Axial confinement of the particles in the two-dimensional interface is maintained by the interplay between surface tension and gravity. Therefore, optical trapping of the micro-beads is possible even with a long distance air objective. Efficient micro-circulation of the liquid can be induced by fast rotating beads, driven by the orbital angular momentum transfer of incident Laguerre-Gaussian (doughnut) laser modes. Our setup allows various ways of creating a tailored dynamic flow of particles and liquid within the surface. We demonstrate examples of surface manipulations like efficient vortex pumps and mixers, interactive particle flow steering by arrays of vortex pumps, the feasibility of achieving a "clocked" traffic of micro beads, and size-selective guiding of beads along optical "conveyor belts".

  5. Combined holographic-mechanical optical tweezers: Construction, optimization, and calibration

    Science.gov (United States)

    Hanes, Richard D. L.; Jenkins, Matthew C.; Egelhaaf, Stefan U.

    2009-08-01

    A spatial light modulator (SLM) and a pair of galvanometer-mounted mirrors (GMM) were combined into an optical tweezers setup. This provides great flexibility as the SLM creates an array of traps, which can be moved smoothly and quickly with the GMM. To optimize performance, the effect of the incidence angle on the SLM with respect to phase and intensity response was investigated. Although it is common to use the SLM at an incidence angle of 45°, smaller angles give a full 2π phase shift and an output intensity which is less dependent on the magnitude of the phase shift. The traps were calibrated using an active oscillatory technique and a passive probability distribution method.

  6. Combined holographic-mechanical optical tweezers: Construction, optimization, and calibration

    International Nuclear Information System (INIS)

    Hanes, Richard D. L.; Jenkins, Matthew C.; Egelhaaf, Stefan U.

    2009-01-01

    A spatial light modulator (SLM) and a pair of galvanometer-mounted mirrors (GMM) were combined into an optical tweezers setup. This provides great flexibility as the SLM creates an array of traps, which can be moved smoothly and quickly with the GMM. To optimize performance, the effect of the incidence angle on the SLM with respect to phase and intensity response was investigated. Although it is common to use the SLM at an incidence angle of 45 deg., smaller angles give a full 2π phase shift and an output intensity which is less dependent on the magnitude of the phase shift. The traps were calibrated using an active oscillatory technique and a passive probability distribution method.

  7. Construction of a high resolution microscope with conventional and holographic optical trapping capabilities.

    Science.gov (United States)

    Butterfield, Jacqualine; Hong, Weili; Mershon, Leslie; Vershinin, Michael

    2013-04-22

    High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads (1) or cellular organelles (2,3), as well as for high spatial and temporal resolution readout of their position relative to the center of the trap. The system described herein has one such "traditional" trap operating at 980 nm. It additionally provides a second optical trapping system that uses a commercially available holographic package to simultaneously create and manipulate complex trapping patterns in the field of view of the microscope (4,5) at a wavelength of 1,064 nm. The combination of the two systems allows for the manipulation of multiple refractive objects at the same time while simultaneously conducting high speed and high resolution measurements of motion and force production at nanometer and piconewton scale.

  8. Enhanced depth-of-field of an integral imaging microscope using a bifocal holographic optical element-micro lens array.

    Science.gov (United States)

    Kwon, Ki-Chul; Lim, Young-Tae; Shin, Chang-Won; Erdenebat, Munkh-Uchral; Hwang, Jae-Moon; Kim, Nam

    2017-08-15

    We propose and implement an integral imaging microscope with extended depth-of-field (DoF) using a bifocal holographic micro lens array (MLA). The properties of the two MLAs are switched via peristrophic multiplexing, where different properties of the MLA are recorded onto the single holographic optical element (HOE). The recorded MLA properties are perpendicular to each other: after the first mode is recorded, the HOE is rotated by 90° clockwise, and the second mode is recorded. The experimental results confirm that the DoF of the integral imaging microscopy system is extended successfully by using the bifocal MLA.

  9. Digital polarization holography advancing geometrical phase optics.

    Science.gov (United States)

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

    2016-08-08

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

  10. Holographic fabrication of 3D photonic crystals through interference of multi-beams with 4 + 1, 5 + 1 and 6 + 1 configurations.

    Science.gov (United States)

    George, D; Lutkenhaus, J; Lowell, D; Moazzezi, M; Adewole, M; Philipose, U; Zhang, H; Poole, Z L; Chen, K P; Lin, Y

    2014-09-22

    In this paper, we are able to fabricate 3D photonic crystals or quasi-crystals through single beam and single optical element based holographic lithography. The reflective optical elements are used to generate multiple side beams with s-polarization and one central beam with circular polarization which in turn are used for interference based holographic lithography without the need of any other bulk optics. These optical elements have been used to fabricate 3D photonic crystals with 4, 5 or 6-fold symmetry. A good agreement has been observed between fabricated holographic structures and simulated interference patterns.

  11. Apparatus and method using a holographic optical element for converting a spectral distribution to image points

    Science.gov (United States)

    McGill, Matthew J. (Inventor); Scott, Vibart S. (Inventor); Marzouk, Marzouk (Inventor)

    2001-01-01

    A holographic optical element transforms a spectral distribution of light to image points. The element comprises areas, each of which acts as a separate lens to image the light incident in its area to an image point. Each area contains the recorded hologram of a point source object. The image points can be made to lie in a line in the same focal plane so as to align with a linear array detector. A version of the element has been developed that has concentric equal areas to match the circular fringe pattern of a Fabry-Perot interferometer. The element has high transmission efficiency, and when coupled with high quantum efficiency solid state detectors, provides an efficient photon-collecting detection system. The element may be used as part of the detection system in a direct detection Doppler lidar system or multiple field of view lidar system.

  12. Radiation-hardened optically reconfigurable gate array exploiting holographic memory characteristics

    Science.gov (United States)

    Seto, Daisaku; Watanabe, Minoru

    2015-09-01

    In this paper, we present a proposal for a radiation-hardened optically reconfigurable gate array (ORGA). The ORGA is a type of field programmable gate array (FPGA). The ORGA configuration can be executed by the exploitation of holographic memory characteristics even if 20% of the configuration data are damaged. Moreover, the optoelectronic technology enables the high-speed reconfiguration of the programmable gate array. Such a high-speed reconfiguration can increase the radiation tolerance of its programmable gate array to 9.3 × 104 times higher than that of current FPGAs. Through experimentation, this study clarified the configuration dependability using the impulse-noise emulation and high-speed configuration capabilities of the ORGA with corrupt configuration contexts. Moreover, the radiation tolerance of the programmable gate array was confirmed theoretically through probabilistic calculation.

  13. Electro-optical properties of low viscosity driven holographic polymer dispersed liquid crystals

    Science.gov (United States)

    Moon, K. R.; Bae, S. Y.; Kim, B. K.

    2015-04-01

    Relative diffraction efficiency (RDE), operating voltage, and response times are most important performance characteristics of holographic polymer dispersed liquid crystals (HPDLC). Two types of triallyl isocyanurate (TI) having different structures were incorporated into the conventional transmission grating of HPDLC. Premix viscosity decreased by 13-18% with up to 3% TI, beyond which it increased. TI eliminated induction period and augmented initial grating formation rate at all contents. Saturation RDE increased over 200% while threshold voltage and rise time decreased to about half and 2/3, respectively up to 3% TI, beyond which the tendencies were reversed. Among the two TIs, low viscosity monomer (TA) showed high RDE, while high miscibility monomer (TE) low characteristic voltages and short response times. It is concluded that grating formation is largely favored by low viscosity, while interface tensions and electro-optical performances by miscibility at similar viscosities.

  14. The use of holographic and diffractive optics for optimized machine vision illumination for critical dimension inspection

    Science.gov (United States)

    Lizotte, Todd E.; Ohar, Orest

    2004-02-01

    Illuminators used in machine vision applications typically produce non-uniform illumination onto the targeted surface being observed, causing a variety of problems with machine vision alignment or measurement. In most circumstances the light source is broad spectrum, leading to further problems with image quality when viewed through a CCD camera. Configured with a simple light bulb and a mirrored reflector and/or frosted glass plates, these general illuminators are appropriate for only macro applications. Over the last 5 years newer illuminators have hit the market including circular or rectangular arrays of high intensity light emitting diodes. These diode arrays are used to create monochromatic flood illumination of a surface that is to be inspected. The problem with these illumination techniques is that most of the light does not illuminate the desired areas, but broadly spreads across the surface, or when integrated with diffuser elements, tend to create similar shadowing effects to the broad spectrum light sources. In many cases a user will try to increase the performance of these illuminators by adding several of these assemblies together, increasing the intensity or by moving the illumination source closer or farther from the surface being inspected. In this case these non-uniform techniques can lead to machine vision errors, where the computer machine vision may read false information, such as interpreting non-uniform lighting or shadowing effects as defects. This paper will cover a technique involving the use of holographic / diffractive hybrid optical elements that are integrated into standard and customized light sources used in the machine vision industry. The bulk of the paper will describe the function and fabrication of the holographic/diffractive optics and how they can be tailored to improve illuminator design. Further information will be provided a specific design and examples of it in operation will be disclosed.

  15. Polarization sensitive optical coherence tomography detection method

    International Nuclear Information System (INIS)

    Colston, B W; DaSilva, L B; Everett, M J; Featherstone, J D B; Fried, D; Ragadio, J N; Sathyam, U S.

    1999-01-01

    This study demonstrates the potential of polarization sensitive optical coherence tomography (PS-OCT) for non-invasive in vivo detection and characterization of early, incipient caries lesions. PS-OCT generates cross-sectional images of biological tissue while measuring the effect of the tissue on the polarization state of incident light. Clear discrimination between regions of normal and demineralized enamel is first shown in PS-OCT images of bovine enamel blocks containing well-characterized artificial lesions. High-resolution, cross-sectional images of extracted human teeth are then generated that clearly discriminate between the normal and carious regions on both the smooth and occlusal surfaces. Regions of the teeth that appeared to be demineralized in the PS-OCT images were verified using histological thin sections examined under polarized light microscopy. The PS-OCT system discriminates between normal and carious regions by measuring the polarization state of the back-scattered 1310 nm light, which is affected by the state of demineralization of the enamel. Demineralization of enamel increases the scattering coefficient, thus depolarizing the incident light. This study shows that PS-OCT has great potential for the detection, characterization, and monitoring of incipient caries lesions

  16. A dual-optically-pumped polarized negative deuterium ion source

    International Nuclear Information System (INIS)

    Kinsho, M.; Mori, Y.; Ikegami, K.; Takagi, A.

    1994-01-01

    An optically pumped polarized H - source (OPPIS), which is based on the charge exchange between H + ions and electron-spin-polarized alkali atoms has been developed at KEK. Just by applying this scheme to a deuteron beam, it is difficult to obtain a highly vector polarized deuteron beam. To obtain highly vector polarized D - ions, we have developed a 'dual optical pumping type' of polarized D - source. With this scheme, a 100% vector nuclear-spin polarization for D - ions is possible in principle. In a preliminary experiment, a 60% of vector nuclear-spin polarized D - ions was obtained. (author)

  17. SLC polarized beam source electron optics design

    International Nuclear Information System (INIS)

    Eppley, K.R.; Lavine, T.L.; Early, R.A.; Herrmannsfeldt, W.B.; Miller, R.H.; Schultz, D.C.; Spencer, C.M.; Yeremian, A.D.

    1991-05-01

    This paper describes the design of the beam-line from the polarized electron gun to the linac injector in the Stanford Linear Collider (SLC). The polarized electron source is a GaAs photocathode, requiring 10 -11 -Torr-range pressure for adequate quantum efficiency and longevity. The photocathode is illuminated by 3-nsec-long laser pulses. The quality of the optics for the 160-kV beam is crucial since electron-stimulated gas desorption from beam loss in excess of 0.1% of the 20-nC pulses may poison the photocathode. Our design for the transport line consists of a differential pumping region isolated by a pair of valves. Focusing is provided by a pair of Helmholtz coils and by several iron-encased solenoidal lenses. Our optics design is based on beam transport simulations using 2 1/2-D particle-in-cell codes to model the gun and to solve the fully-relativistic time-dependent equations of motion in three dimensions for electrons in the presence of azimuthally symmetric electromagnetic fields. 6 refs., 6 figs

  18. All-optical bidirectional neural interfacing using hybrid multiphoton holographic optogenetic stimulation.

    Science.gov (United States)

    Paluch-Siegler, Shir; Mayblum, Tom; Dana, Hod; Brosh, Inbar; Gefen, Inna; Shoham, Shy

    2015-07-01

    Our understanding of neural information processing could potentially be advanced by combining flexible three-dimensional (3-D) neuroimaging and stimulation. Recent developments in optogenetics suggest that neurophotonic approaches are in principle highly suited for noncontact stimulation of network activity patterns. In particular, two-photon holographic optical neural stimulation (2P-HONS) has emerged as a leading approach for multisite 3-D excitation, and combining it with temporal focusing (TF) further enables axially confined yet spatially extended light patterns. Here, we study key steps toward bidirectional cell-targeted 3-D interfacing by introducing and testing a hybrid new 2P-TF-HONS stimulation path for accurate parallel optogenetic excitation into a recently developed hybrid multiphoton 3-D imaging system. The system is shown to allow targeted all-optical probing of in vitro cortical networks expressing channelrhodopsin-2 using a regeneratively amplified femtosecond laser source tuned to 905 nm. These developments further advance a prospective new tool for studying and achieving distributed control over 3-D neuronal circuits both in vitro and in vivo.

  19. Temperature dependence of Kerr coefficient and quadratic polarized optical coefficient of a paraelectric Mn:Fe:KTN crystal

    Directory of Open Access Journals (Sweden)

    Qieni Lu

    2015-08-01

    Full Text Available We measure temperature dependence on Kerr coefficient and quadratic polarized optical coefficient of a paraelectric Mn:Fe:KTN crystal simultaneously in this work, based on digital holographic interferometry (DHI. And the spatial distribution of the field-induced refractive index change can also be visualized and estimated by numerically retrieving sequential phase maps of Mn:Fe:KTN crystal from recording digital holograms in different states. The refractive indices decrease with increasing temperature and quadratic polarized optical coefficient is insensitive to temperature. The experimental results suggest that the DHI method presented here is highly applicable in both visualizing the temporal and spatial behavior of the internal electric field and accurately measuring electro-optic coefficient for electrooptical media.

  20. Digital holographic interferometry: A novel optical calorimetry technique for radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cavan, Alicia, E-mail: alicia.cavan@cdhb.health.nz [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand and Christchurch Hospital, Private Bag 4710, Christchurch 8140 (New Zealand); Meyer, Juergen, E-mail: juergen@uw.edu [Department of Radiation Oncology, University of Washington, 1959 Northeast Pacific Street, Box 356043, Seattle, Washington 98195 (United States)

    2014-02-15

    Purpose: To develop and demonstrate the proof-of-principle of a novel optical calorimetry method to determine radiation absorbed dose in a transparent medium. Methods: The calorimetric property of water is measured during irradiation by means of an interferometer, which detects temperature-induced changes in the refractive index that can be mathematically related to absorbed dose. The proposed method uses a technique called digital holographic interferometry (DHI), which comprises an optical laser interferometer setup and consecutive physical reconstruction of the recorded wave fronts by means of the Fresnel transform. This paper describes the conceptual framework and provides the mathematical basis for DHI dosimetry. Dose distributions from a high dose rate Brachytherapy source were measured by a prototype optical setup to demonstrate the feasibility of the approach. Results: The developed DHI dosimeter successfully determined absorbed dose distributions in water in the region adjacent to a high dose rate Brachytherapy source. A temperature change of 0.0381 K across a distance of 6.8 mm near the source was measured, corresponding to a dose of 159.3 Gy. The standard deviation in a typical measurement set was ±3.45 Gy (corresponding to an uncertainty in the temperature value of ±8.3 × 10{sup −4} K). The relative dose fall off was in agreement with treatment planning system modeled data. Conclusions: First results with a prototype optical setup and a Brachytherapy source demonstrate the proof-of-principle of the approach. The prototype achieves high spatial resolution of approximately 3 × 10{sup −5} m. The general approach is fundamentally independent of the radiation type and energy. The sensitivity range determined indicates that the method is predominantly suitable for high dose rate applications. Further work is required to determine absolute dose in all three dimensions.

  1. Vector optical fields with bipolar symmetry of linear polarization.

    Science.gov (United States)

    Pan, Yue; Li, Yongnan; Li, Si-Min; Ren, Zhi-Cheng; Si, Yu; Tu, Chenghou; Wang, Hui-Tian

    2013-09-15

    We focus on a new kind of vector optical field with bipolar symmetry of linear polarization instead of cylindrical and elliptical symmetries, enriching members of family of vector optical fields. We design theoretically and generate experimentally the demanded vector optical fields and then explore some novel tightly focusing properties. The geometric configurations of states of polarization provide additional degrees of freedom assisting in engineering the field distribution at the focus to the specific applications such as lithography, optical trapping, and material processing.

  2. Multiport optical circulator by using polarizing beam splitter cubes as spatial walk-off polarizers.

    Science.gov (United States)

    Chen, Jing-Heng; Chen, Kun-Huang; Lin, Jiun-You; Hsieh, Hsiang-Yung

    2010-03-10

    Optical circulators are necessary passive devices applied in optical communication systems. In the design of optical circulators, the implementation of the function of spatial walk-off polarizers is a key technique that significantly influences the performance and cost of a device. This paper proposes a design of a multiport optical circulator by using polarizing beam splitter cubes as spatial walk-off polarizers. To show the feasibility of the design, a prototype of a six-port optical circulator was fabricated. The insertion losses are 0.94-1.49 dB, the isolations are 25-51 dB, and return losses are 27.72 dB.

  3. High contrast laser beam collimation testing using two proximately placed holographic optical elements

    Science.gov (United States)

    Rajkumar; Dubey, Rajiv; Debnath, Sanjit K.; Chhachhia, D. P.

    2018-05-01

    Accuracy in laser beam collimation is very important in systems used for precision measurements. The present work reports a technique for collimation testing of laser beams using two proximately placed holographic optical elements (HOEs). The required HOEs are designed and fabricated such that upon illumination with the test beam, they release two laterally sheared wavefronts, at desired angles from the directly transmitted beam, that superimpose each other to generate straight interference fringes. Deviation from the collimation of the test beam results in orientation of these otherwise horizontal fringes. The novelty of this setup comes from the fact that HOEs are lightweight, as well as easy to fabricate as compared to conventional wedge plates used for collimation testing, and generate high contrast fringes compared to other interferometry, holography, Talbot and Moiré based techniques in a compact manner. The proposed technique is experimentally validated by measuring the orientation of fringes by an angle of 16.4° when a collimating lens of focal length 200 mm is defocused by 600 μm. The accuracy in the setting of this collimation position is obtained to be 10 μm.

  4. Transparent thin film polarizing and optical control systems

    Directory of Open Access Journals (Sweden)

    Nelson V. Tabiryan

    2011-06-01

    Full Text Available We show that a diffractive waveplate can be combined with a phase retardation film for fully converting light of arbitrary polarization state into a polarized light. Incorporating a photonic bandgap layer into a system of such polarizers that unify different polarization states in the input light into a single polarization state at its output, rather than absorbing or reflecting half of it, we developed and demonstrated a polarization-independent optical controller capable of switching between transmittive and reflective states. The transition between those states is smoothly controlled with low-voltage and low-power sources. Using versatile fabrication methods, this “universally polarizing optical controller” can be integrated into a thin package compatible with a variety of display, spatial light modulation, optical communication, imaging and other photonics systems.

  5. Optical and diffractive properties of polymer: nanoparticles periodic structures obtained by holographic method

    Science.gov (United States)

    Smirnova, T. N.; Sakhno, O. V.; Goldberg, L.; Stumpe, J.

    2007-06-01

    The ordering of nanoparticles in polymer matrix using holographic photopolymerization is investigated. The general approach to the selection of the photopolymerizable compounds is proposed. The nonlinear and luminescent properties of obtained gratings are studied.

  6. Three-dimensional motion-picture imaging of dynamic object by parallel-phase-shifting digital holographic microscopy using an inverted magnification optical system

    Science.gov (United States)

    Fukuda, Takahito; Shinomura, Masato; Xia, Peng; Awatsuji, Yasuhiro; Nishio, Kenzo; Matoba, Osamu

    2017-04-01

    We constructed a parallel-phase-shifting digital holographic microscopy (PPSDHM) system using an inverted magnification optical system, and succeeded in three-dimensional (3D) motion-picture imaging for 3D displacement of a microscopic object. In the PPSDHM system, the inverted and afocal magnification optical system consisted of a microscope objective (16.56 mm focal length and 0.25 numerical aperture) and a convex lens (300 mm focal length and 82 mm aperture diameter). A polarization-imaging camera was used to record multiple phase-shifted holograms with a single-shot exposure. We recorded an alum crystal, sinking down in aqueous solution of alum, by the constructed PPSDHM system at 60 frames/s for about 20 s and reconstructed high-quality 3D motion-picture image of the crystal. Then, we calculated amounts of displacement of the crystal from the amounts in the focus plane and the magnifications of the magnification optical system, and obtained the 3D trajectory of the crystal by that amounts.

  7. Phase recording for formation of holographic optical elements on silver-halide photographic emulsions

    Science.gov (United States)

    Ganzherli, Nina M.; Gulyaev, Sergey N.; Maurer, Irina A.; Chernykh, Dmitrii F.

    2009-05-01

    Holographic fabrication methods of regular and nonregular relief-phase structures on silver-halide photographic emulsions are considered. Methods of gelatin photodestruction under short-wave ultra-violet radiation and chemical hardening with the help of dichromated solutions were used as a technique for surface relief formation. The developed techniques permitted us to study specimens of holographic diffusers and microlens rasters with small absorption and high light efficiency.

  8. Investigation on cytoskeleton dynamics for no-adherent cells subjected to point-like stimuli by digital holographic microscopy and holographic optical trapping

    Science.gov (United States)

    Miccio, Lisa; Merola, Francesco; Memmolo, Pasquale; Mugnano, Martina; Fusco, Sabato; Netti, Paolo A.; Ferraro, Pietro

    2014-05-01

    Guiding, controlling and studying cellular functions are challenging themes in the biomedical field, as they are fundamental prerequisites for new therapeutic strategies from tissue regeneration to controlled drug delivery. In recent years, multidisciplinary studies in nanotechnology offer new tools to investigate important biophysical phenomena in response to the local physical characteristics of the extracellular environment, some examples are the mechanisms of cell adhesion, migration, communication and differentiation. Indeed for reproducing the features of the extracellular matrix in vitro, it is essential to develop active devices that evoke as much as possible the natural cellular environment. Our investigation is in the framework of studying and clarifying the biophysical mechanisms of the interaction between cells and the microenvironment in which they exist. We implement an optical tweezers setup to investigate cell material interaction and we use Digital Holography as non-invasive imaging technique in microscopy. We exploit Holographic Optical Tweezers arrangement in order to trap and manage functionalized micrometric latex beads to induce mechanical deformation in suspended cells. A lot of papers in literature examine the dynamics of the cytoskeleton when cells adhere on substrates and nowadays well established cell models are based on such research activities. Actually, the natural cell environment is made of a complex extracellular matrix and the single cell behavior is due to intricate interactions with the environment and are strongly correlated to the cell-cell interactions. Our investigation is devoted to understand the inner cell mechanism when it is mechanically stressed by point-like stimulus without the substrate influence.

  9. Application of fluidic lens technology to an adaptive holographic optical element see-through autophoropter

    Science.gov (United States)

    Chancy, Carl H.

    A device for performing an objective eye exam has been developed to automatically determine ophthalmic prescriptions. The closed loop fluidic auto-phoropter has been designed, modeled, fabricated and tested for the automatic measurement and correction of a patient's prescriptions. The adaptive phoropter is designed through the combination of a spherical-powered fluidic lens and two cylindrical fluidic lenses that are orientated 45o relative to each other. In addition, the system incorporates Shack-Hartmann wavefront sensing technology to identify the eye's wavefront error and corresponding prescription. Using the wavefront error information, the fluidic auto-phoropter nulls the eye's lower order wavefront error by applying the appropriate volumes to the fluidic lenses. The combination of the Shack-Hartmann wavefront sensor the fluidic auto-phoropter allows for the identification and control of spherical refractive error, as well as cylinder error and axis; thus, creating a truly automated refractometer and corrective system. The fluidic auto-phoropter is capable of correcting defocus error ranging from -20D to 20D and astigmatism from -10D to 10D. The transmissive see-through design allows for the observation of natural scenes through the system at varying object planes with no additional imaging optics in the patient's line of sight. In this research, two generations of the fluidic auto-phoropter are designed and tested; the first generation uses traditional glass optics for the measurement channel. The second generation of the fluidic auto-phoropter takes advantage of the progress in the development of holographic optical elements (HOEs) to replace all the traditional glass optics. The addition of the HOEs has enabled the development of a more compact, inexpensive and easily reproducible system without compromising its performance. Additionally, the fluidic lenses were tested during a National Aeronautics Space Administration (NASA) parabolic flight campaign, to

  10. Optical vector network analyzer with improved accuracy based on polarization modulation and polarization pulling.

    Science.gov (United States)

    Li, Wei; Liu, Jian Guo; Zhu, Ning Hua

    2015-04-15

    We report a novel optical vector network analyzer (OVNA) with improved accuracy based on polarization modulation and stimulated Brillouin scattering (SBS) assisted polarization pulling. The beating between adjacent higher-order optical sidebands which are generated because of the nonlinearity of an electro-optic modulator (EOM) introduces considerable error to the OVNA. In our scheme, the measurement error is significantly reduced by removing the even-order optical sidebands using polarization discrimination. The proposed approach is theoretically analyzed and experimentally verified. The experimental results show that the accuracy of the OVNA is greatly improved compared to a conventional OVNA.

  11. Three-dimensional holographic optical manipulation through a high-numerical-aperture soft-glass multimode fibre

    Science.gov (United States)

    Leite, Ivo T.; Turtaev, Sergey; Jiang, Xin; Šiler, Martin; Cuschieri, Alfred; Russell, Philip St. J.; Čižmár, Tomáš

    2018-01-01

    Holographic optical tweezers (HOT) hold great promise for many applications in biophotonics, allowing the creation and measurement of minuscule forces on biomolecules, molecular motors and cells. Geometries used in HOT currently rely on bulk optics, and their exploitation in vivo is compromised by the optically turbid nature of tissues. We present an alternative HOT approach in which multiple three-dimensional (3D) traps are introduced through a high-numerical-aperture multimode optical fibre, thus enabling an equally versatile means of manipulation through channels having cross-section comparable to the size of a single cell. Our work demonstrates real-time manipulation of 3D arrangements of micro-objects, as well as manipulation inside otherwise inaccessible cavities. We show that the traps can be formed over fibre lengths exceeding 100 mm and positioned with nanometric resolution. The results provide the basis for holographic manipulation and other high-numerical-aperture techniques, including advanced microscopy, through single-core-fibre endoscopes deep inside living tissues and other complex environments.

  12. Polarization-dependent optics using gauge-field metamaterials

    International Nuclear Information System (INIS)

    Liu, Fu; Xiao, Shiyi; Li, Jensen; Wang, Saisai; Hang, Zhi Hong

    2015-01-01

    We show that effective gauge field for photons with polarization-split dispersion surfaces, being realized using uniaxial metamaterials, can be used for polarization control with unique opportunities. The metamaterials with the proposed gauge field correspond to a special choice of eigenpolarizations on the Poincaré sphere as pseudo-spins, in contrary to those from either conventional birefringent crystals or optical active media. It gives rise to all-angle polarization control and a generic route to manipulate photon trajectories or polarizations in the pseudo-spin domain. As demonstrations, we show beam splitting (birefringent polarizer), all-angle polarization control, unidirectional polarization filter, and interferometer as various polarization control devices in the pseudo-spin domain. We expect that more polarization-dependent devices can be designed under the same framework

  13. Image scale measurement with correlation filters in a volume holographic optical correlator

    Science.gov (United States)

    Zheng, Tianxiang; Cao, Liangcai; He, Qingsheng; Jin, Guofan

    2013-08-01

    A search engine containing various target images or different part of a large scene area is of great use for many applications, including object detection, biometric recognition, and image registration. The input image captured in realtime is compared with all the template images in the search engine. A volume holographic correlator is one type of these search engines. It performs thousands of comparisons among the images at a super high speed, with the correlation task accomplishing mainly in optics. However, the inputted target image always contains scale variation to the filtering template images. At the time, the correlation values cannot properly reflect the similarity of the images. It is essential to estimate and eliminate the scale variation of the inputted target image. There are three domains for performing the scale measurement, as spatial, spectral and time domains. Most methods dealing with the scale factor are based on the spatial or the spectral domains. In this paper, a method with the time domain is proposed to measure the scale factor of the input image. It is called a time-sequential scaled method. The method utilizes the relationship between the scale variation and the correlation value of two images. It sends a few artificially scaled input images to compare with the template images. The correlation value increases and decreases with the increasing of the scale factor at the intervals of 0.8~1 and 1~1.2, respectively. The original scale of the input image can be measured by estimating the largest correlation value through correlating the artificially scaled input image with the template images. The measurement range for the scale can be 0.8~4.8. Scale factor beyond 1.2 is measured by scaling the input image at the factor of 1/2, 1/3 and 1/4, correlating the artificially scaled input image with the template images, and estimating the new corresponding scale factor inside 0.8~1.2.

  14. Study on polarized optical flow algorithm for imaging bionic polarization navigation micro sensor

    Science.gov (United States)

    Guan, Le; Liu, Sheng; Li, Shi-qi; Lin, Wei; Zhai, Li-yuan; Chu, Jin-kui

    2018-05-01

    At present, both the point source and the imaging polarization navigation devices only can output the angle information, which means that the velocity information of the carrier cannot be extracted from the polarization field pattern directly. Optical flow is an image-based method for calculating the velocity of pixel point movement in an image. However, for ordinary optical flow, the difference in pixel value as well as the calculation accuracy can be reduced in weak light. Polarization imaging technology has the ability to improve both the detection accuracy and the recognition probability of the target because it can acquire the extra polarization multi-dimensional information of target radiation or reflection. In this paper, combining the polarization imaging technique with the traditional optical flow algorithm, a polarization optical flow algorithm is proposed, and it is verified that the polarized optical flow algorithm has good adaptation in weak light and can improve the application range of polarization navigation sensors. This research lays the foundation for day and night all-weather polarization navigation applications in future.

  15. Optically pumped polarized 23Na vapor target for use in polarized ion source. Technical progress report

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1984-01-01

    We are currently measuring relaxation times in an optically pumped 23 Na vapor target. Our research is directed toward improvements in the optically pumped Na vapor targets used for the production of polarized H - ions. In this progress report we review the properties of the optically pumped polarized H - ion source and especially the optically pumped Na vapor target employed in this source as well as discussing the progress of our research on relaxation times in an optically pumped Na vapor target. 30 references, 6 figures, 3 tables

  16. Nonlinear polarization effects in a birefringent single mode optical fiber

    International Nuclear Information System (INIS)

    Ishiekwene, G.C.; Mensah, S.Y.; Brown, C.S.

    2001-04-01

    The nonlinear polarization effects in a birefringent single mode optical fiber is studied using Jacobi elliptic functions. We find that the polarization state of the propagating beam depends on the initial polarization as well as the intensity of the input light in a complicated way. The Stokes polarization parameters are either periodic or aperiodic depending on the value of the Jacobian modulus. Our calculations suggest that the effective beat length of the fiber can become infinite at a higher critical value of the input power when polarization dependent losses are considered. (author)

  17. Thermally and optically tunable lasing properties from dye-doped holographic polymer dispersed liquid crystal in capillaries

    Science.gov (United States)

    Chen, Maozhou; Dai, Haitao; Wang, Dongshuo; Yang, Yue; Luo, Dan; Zhang, Xiaodong; Liu, Changlong

    2018-03-01

    In this paper, we investigated tunable lasing properties from the dye-doped holographic polymer dispersed liquid crystal (HPDLC) gratings in capillaries with thermal and optical manners. The thermally tunable range of the lasing from the dye-doped HPDLC reached 8.60 nm with the temperature ranging from 23 °C to 50 °C. The optically tunable laser emission was achieved by doping azo-dye in HPDLC. The transition of azo-dye from trans- to cis-state could induce the reorientation of LC molecules after UV light irradiation, which resulted in the variation of refractive index contrast of LC-rich/polymer-rich layer in HPDLC. Experimentally, the emission wavelength of lasing showed a blueshift (about 2 nm) coupled with decreasing output intensities. The tunable laser based on HPDLC may enable more applications in laser displays, optical communication, biosensors, etc.

  18. Design of a tensor polarized deuterium target polarized by spin-exchange with optically pumped NA

    International Nuclear Information System (INIS)

    Green, M.C.

    1984-01-01

    A proposed design for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) for nuclear physics studies in an electron storage ring accelerator is presented. The deuterium atoms undergo electron spin exchange with a highly polarized sodium vapor; this polarization is transferred to the deuterium nuclei via the hyperfine interaction. The deuterium nuclei obtain their tensor polarization through repeated electron spin exchange/hyperfine interactions. The sodium vapor polarization is maintained by standard optical pumping techniques. Model calculations are presented in detail leading to a discussion of the expected performance and the technical obstacles to be surmounted in the development of such a target

  19. Design of a tensor polarized deuterium target polarized by spin-exchange with optically pumped NA

    International Nuclear Information System (INIS)

    Green, M.C.

    1984-05-01

    A proposed design for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) for nuclear physics studies in an electron storage ring accelerator is presented. The deuterium atoms undergo electron spin exchange with a highly polarized sodium vapor; this polarization is transferred to the deuterium nuclei via the hyperfine interaction. The deuterium nuclei obtain their tensor polarization through repeated electron spin exchange/hyperfine interactions. The sodium vapor polarization is maintained by standard optical pumping techniques. Model calculations are presented in detail leading to a discussion of the expected performance and the technical obstacles to be surmounted in the development of such a target. 15 references, 10 figures

  20. Polarization ray tracing in anisotropic optically active media. I. Algorithms

    International Nuclear Information System (INIS)

    McClain, S.C.; Hillman, L.W.; Chipman, R.A.

    1993-01-01

    Procedures for performing polarization ray tracing through birefringent media are presented in a form compatible with the standard methods of geometrical ray tracing. The birefringent materials treated include the following: anisotropic optically active materials such as quartz, non-optically active uniaxial materials such as calcite, and isotropic optically active materials such as mercury sulfide and organic liquids. Refraction and reflection algorithms are presented that compute both ray directions and wave directions. Methods for computing polarization modes, refractive indices, optical path lengths, and Fresnel transmission and reflection coefficients are also specified. A numerical example of these algorithms is given for analyzing the field of view of a quartz rotator. 37 refs., 3 figs

  1. Fiber-Based Polarization Diversity Detection for Polarization-Sensitive Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Hamid Pahlevaninezhad

    2014-09-01

    Full Text Available We present a new fiber-based polarization diversity detection (PDD scheme for polarization sensitive optical coherence tomography (PSOCT. This implementation uses a new custom miniaturized polarization-maintaining fiber coupler with single mode (SM fiber inputs and polarization maintaining (PM fiber outputs. The SM fiber inputs obviate matching the optical lengths of the two orthogonal OCT polarization channels prior to interference while the PM fiber outputs ensure defined orthogonal axes after interference. Advantages of this detection scheme over those with bulk optics PDD include lower cost, easier miniaturization, and more relaxed alignment and handling issues. We incorporate this PDD scheme into a galvanometer-scanned OCT system to demonstrate system calibration and PSOCT imaging of an achromatic quarter-wave plate, fingernail in vivo, and chicken breast, salmon, cow leg, and basa fish muscle samples ex vivo.

  2. Polarization encoded all-optical multi-valued shift operators

    Science.gov (United States)

    Roy, Jitendra Nath; Bhowmik, Panchatapa

    2014-08-01

    Polarization encoded multi-valued (both ternary and quaternary logic) shift operators have been designed using linear optical devices only. There are six ternary and 24 quaternary shift operators in multi-valued system. These are also known as reversible literals. This circuit will be useful in future all-optical multi-valued logic based information processing system. Different states of polarization of light are taken as different logic states.

  3. Optical characterization and polarization calibration for rigid endoscopes

    Science.gov (United States)

    Garcia, Missael; Gruev, Viktor

    2017-02-01

    Polarization measurements give orthogonal information to spectral images making them a great tool in the characterization of environmental parameters in nature. Thus, polarization imagery has proven to be remarkably useful in a vast range of biomedical applications. One such application is the early diagnosis of flat cancerous lesions in murine colorectal tumor models, where polarization data complements NIR fluorescence analysis. Advances in nanotechnology have led to compact and precise bio-inspired imaging sensors capable of accurately co-registering multidimensional spectral and polarization information. As more applications emerge for these imagers, the optics used in these instruments get very complex and can potentially compromise the original polarization state of the incident light. Here we present a complete optical and polarization characterization of three rigid endoscopes of size 1.9mm x 10cm (Karl Storz, Germany), 5mm x 30cm, and 10mm x 33cm (Olympus, Germany), used in colonoscopy for the prevention of colitis-associated cancer. Characterization results show that the telescope optics act as retarders and effectively depolarize the linear component. These incorrect readings can cause false-positives or false-negatives leading to an improper diagnosis. In this paper, we offer a polarization calibration scheme for these endoscopes based on Mueller calculus. By modeling the optical properties from training data as real-valued Mueller matrices, we are able to successfully reconstruct the initial polarization state acquired by the imaging system.

  4. Polarization modulational instability in a birefringent optical fiber ...

    Indian Academy of Sciences (India)

    effects on PMI gain spectra of a linearly polarized intense pump wave which experiences periodic nonlinear polarization rotation in a birefringent optical fiber in both the anomalous and normal dispersion regimes. The paper is arranged as follows: In Ü2, we briefly discuss the basic equation. In Ü3, using Floquet theorem ...

  5. McDONALD OBSERVATORY ARCHIVE OF OPTICAL LINEAR POLARIZATION MEASUREMENTS

    International Nuclear Information System (INIS)

    Wills, Beverley J.; Wills, D.; Breger, M.

    2011-01-01

    We present 990 previously unpublished optical linear polarization measurements of quasars, active galactic nuclei, and some stars observed for interstellar polarization. The observations, covering the period 1981-2000, were made with McDonald Observatory's 2.1 m Struve reflector and the Breger photopolarimeter.

  6. Simultaneous optical and infrared polarization measurements of blazars

    International Nuclear Information System (INIS)

    Brindle, C.; Hough, J.H.; Bailey, J.A.; Axon, D.J.; Hyland, A.R.

    1986-01-01

    Measurements are presented of the polarization and flux of a sample of 28 blazars (21 BL Lacs and 7 OVV quasars) at optical and near-infrared wavelengths, with repeated observations for some objects. For 20 objects, these are the first reported polarization measurements in either the optical or infrared, and for most of them the first simultaneous measurements at these wavelengths. Out of a total of 42 observations a spectral dependence of polarization level and position angle is found, although not necessarily occurring together, on 15 occasions. (author)

  7. Early optical polarization of a gamma-ray burst afterglow.

    Science.gov (United States)

    Mundell, Carole G; Steele, Iain A; Smith, Robert J; Kobayashi, Shiho; Melandri, Andrea; Guidorzi, Cristiano; Gomboc, Andreja; Mottram, Chris J; Clarke, David; Monfardini, Alessandro; Carter, David; Bersier, David

    2007-03-30

    We report the optical polarization of a gamma-ray burst (GRB) afterglow, obtained 203 seconds after the initial burst of gamma-rays from GRB 060418, using a ring polarimeter on the robotic Liverpool Telescope. Our robust (2sigma) upper limit on the percentage of polarization, less than 8%, coincides with the fireball deceleration time at the onset of the afterglow. The combination of the rate of decay of the optical brightness and the low polarization at this critical time constrains standard models of GRB ejecta, ruling out the presence of a large-scale ordered magnetic field in the emitting region.

  8. Real-time optical correlator using computer-generated holographic filter on a liquid crystal light valve

    Science.gov (United States)

    Chao, Tien-Hsin; Yu, Jeffrey

    1990-01-01

    Limitations associated with the binary phase-only filter often used in optical correlators are presently circumvented in the writing of complex-valued data on a gray-scale spatial light modulator through the use of a computer-generated hologram (CGH) algorithm. The CGH encodes complex-valued data into nonnegative real CGH data in such a way that it may be encoded in any of the available gray-scale spatial light modulators. A CdS liquid-crystal light valve is used for the complex-valued CGH encoding; computer simulations and experimental results are compared, and the use of such a CGH filter as the synapse hologram in a holographic optical neural net is discussed.

  9. Laboratory-based recording of holographic fine structure in X-ray absorption anisotropy using polycapillary optics

    Energy Technology Data Exchange (ETDEWEB)

    Dabrowski, K.M. [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland); Korecki, P., E-mail: pawel.korecki@uj.edu.pl [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Holographic fine structures in X-ray absorption recorded using a tabletop setup. Black-Right-Pointing-Pointer Setup based on polycapillary collimating optics and an HOPG crystal. Black-Right-Pointing-Pointer Demonstration of element sensitivity by detection of X-ray fluorescence. Black-Right-Pointing-Pointer Potential of laboratory-based experiments for heavily doped crystals and thin films. - Abstract: A tabletop setup composed of a collimating polycapillary optics and a highly oriented pyrolytic graphite monochromator (HOPG) was characterized and used for recording two-dimensional maps of X-ray absorption anisotropy (XAA). XAA originates from interference of X-rays directly inside the sample. Depending on experimental conditions, fine structures in XAA can be interpreted in terms of X-ray holograms or X-ray standing waves and can be used for an element selective atomic-resolved structural analysis. The implementation of polycapillary optics resulted in a two-order of magnitude gain in the radiant intensity (photons/s/solid angle) as compared to a system without optics and enabled efficient recording of XAA with a resolution of 0.15 Degree-Sign for Mo K{alpha} radiation. Element sensitivity was demonstrated by acquisition of distinct XAA signals for Ga and As atoms in a GaAs (1 1 1) wafer by using X-ray fluorescence as a secondary signal. These results indicate the possibility of performing laboratory-based XAA experiments for heavily doped single crystals or thin films. So far, because of the weak holographic modulation of XAA, such experiments could be only performed using synchrotron radiation.

  10. Active polarization imaging system based on optical heterodyne balanced receiver

    Science.gov (United States)

    Xu, Qian; Sun, Jianfeng; Lu, Zhiyong; Zhou, Yu; Luan, Zhu; Hou, Peipei; Liu, liren

    2017-08-01

    Active polarization imaging technology has recently become the hot research field all over the world, which has great potential application value in the military and civil area. By introducing active light source, the Mueller matrix of the target can be calculated according to the incident light and the emitted or reflected light. Compared with conventional direct detection technology, optical heterodyne detection technology have higher receiving sensitivities, which can obtain the whole amplitude, frequency and phase information of the signal light. In this paper, an active polarization imaging system will be designed. Based on optical heterodyne balanced receiver, the system can acquire the horizontal and vertical polarization of reflected optical field simultaneously, which contain the polarization characteristic of the target. Besides, signal to noise ratio and imaging distance can be greatly improved.

  11. High-energy nuclear optics of polarized particles

    CERN Document Server

    Baryshevsky, Vladimir G

    2012-01-01

    The various phenomena caused by refraction and diffraction of polarized elementary particles in matter have opened up a new research area in the particle physics: nuclear optics of polarized particles. Effects similar to the well-known optical phenomena such as birefringence and Faraday effects, exist also in particle physics, though the particle wavelength is much less than the distance between atoms of matter. Current knowledge of the quasi-optical effects, which exist for all particles in any wavelength range (and energies from low to extremely high), will enable us to investigate different properties of interacting particles (nuclei) in a new aspect. This pioneering book will provide detailed accounts of quasi-optical phenomena in the particle polarization, and will interest physicists and professionals in experimental particle physics.

  12. A cryogenic optical feedthrough using polarization maintaining fibers.

    Science.gov (United States)

    Nelson, M J; Collins, C J; Speake, C C

    2016-03-01

    Polarization maintaining optical fibers can be used to transmit linearly polarized light over long distances but their use in cryogenic environments has been limited by their sensitivity to temperature changes and associated mechanical stress. We investigate experimentally how thermal stresses affect the polarization maintaining fibers and model the observations with Jones matrices. We describe the design, construction, and testing of a feedthrough and fiber termination assembly that uses polarization maintaining fiber to transmit light from a 633 nm HeNe laser at room temperature to a homodyne polarization-based interferometer in a cryogenic vacuum. We report on the efficiency of the polarization maintaining properties of the feedthrough assembly. We also report that, at cryogenic temperatures, the interferometer can achieve a sensitivity of 8 × 10(-10) rad/√Hz at 0.05 Hz using this feedthrough.

  13. Direct detection of the optical field beyond single polarization mode.

    Science.gov (United States)

    Che, Di; Sun, Chuanbowen; Shieh, William

    2018-02-05

    Direct detection is traditionally regarded as a detection method that recovers only the optical intensity. Compared with coherent detection, it owns a natural advantage-the simplicity-but lacks a crucial capability of field recovery that enables not only the multi-dimensional modulation, but also the digital compensation of the fiber impairments linear with the optical field. Full-field detection is crucial to increase the capacity-distance product of optical transmission systems. A variety of methods have been investigated to directly detect the optical field of the single polarization mode, which normally sends a carrier traveling with the signal for self-coherent detection. The crux, however, is that any optical transmission medium supports at least two propagating modes (e.g. single mode fiber supports two polarization modes), and until now there is no direct detection that can recover the complete set of optical fields beyond one polarization, due to the well-known carrier fading issue after mode demultiplexing induced by the random mode coupling. To avoid the fading, direct detection receivers should recover the signal in an intensity space isomorphic to the optical field without loss of any degrees of freedom, and a bridge should be built between the field and its isomorphic space for the multi-mode field recovery. Based on this thinking, we propose, for the first time, the direct detection of dual polarization modes by a novel receiver concept, the Stokes-space field receiver (SSFR) and its extension, the generalized SSFR for multiple spatial modes. The idea is verified by a dual-polarization field recovery of a polarization-multiplexed complex signal over an 80-km single mode fiber transmission. SSFR can be applied to a much wider range of fields beyond optical communications such as coherent sensing and imaging, where simple field recovery without an extra local laser is desired for enhanced system performance.

  14. Off-axis full-field swept-source optical coherence tomography using holographic refocusing

    Science.gov (United States)

    Hillmann, Dierck; Franke, Gesa; Hinkel, Laura; Bonin, Tim; Koch, Peter; Hüttmann, Gereon

    2013-03-01

    We demonstrate a full-field swept-source OCT using an off-axis geometry of the reference illumination. By using holographic refocusing techniques, a uniform lateral resolution is achieved over the measurement depth of approximately 80 Rayleigh lengths. Compared to a standard on-axis setup, artifacts and autocorrelation signals are suppressed and the measurement depth is doubled by resolving the complex conjugate ambiguity. Holographic refocusing was done efficiently by Fourier-domain resampling as demonstrated before in inverse scattering and holoscopy. It allowed to reconstruct a complete volume with about 10μm resolution over the complete measurement depth of more than 10mm. Off-axis full-field swept-source OCT enables high measurement depths, spanning many Rayleigh lengths with reduced artifacts.

  15. Demonstration of holographic smart card system using the optical memory technology

    Science.gov (United States)

    Kim, JungHoi; Choi, JaeKwang; An, JunWon; Kim, Nam; Lee, KwonYeon; Jeon, SeckHee

    2003-05-01

    In this paper, we demonstrate the holographic smart card system using digital holographic memory technique that uses reference beam encrypted by the random phase mask to prevent unauthorized users from accessing the stored digital page. The input data that include document data, a picture of face, and a fingerprint for identification is encoded digitally and then coupled with the reference beam modulated by a random phase mask. Therefore, this proposed system can execute recording in the order of MB~GB and readout all personal information from just one card without any additional database system. Also, recorded digital holograms can't be reconstructed without a phase key and can't be copied by using computers, scanners, or photography.

  16. Studies on optical pumping cells (OPC) to polarize 3He

    International Nuclear Information System (INIS)

    Hutanu, V.; Rupp, A.

    2004-01-01

    The technique applied at HMI to obtain nuclear-spin-polarized 3 He, used in neutron spin filters (NSFs), is metastability-exchange optical pumping. To prepare efficient NSF, one must highly polarize 3 He nuclei in the optical pumping volume (OPV) and reduce the polarization losses during the compression phase. Great progress has been achieved in reducing of depolarization due to the recent development of both, large polarization preserving piston compressors and long relaxation time filter cells. It is even more important to significantly enhance the 3 He polarization rate during optical pumping in order to increase NSF efficiency. Different cells materials were tested, such as Duran and quartz glass. In order to use the laser light more efficiently and to decrease the risk of 3 He depolarization due to unfavorable reflections, antireflection (AR) coatings were used on cell windows made of quartz glass. They were compared with the ones without coating, made of quartz, Duran and BK7 glass. The comparison of various techniques to mount the windows such as blowing, gluing or molecular diffusion was also conducted. It indicated that the molecular diffusion is the most suitable technique because of a better purity of the gas in the cell and the preservation of the optical flatness of the windows. Cells, for practical reasons each entirely made from the same material (Duran, Quartz glass) with windows mounted using this method, showed the best polarization performance

  17. Optically pumped electron spin polarized targets for use in the production of polarized ion beams

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1979-01-01

    The production of relatively dense electron spin polarized alkali metal vapor targets by optical pumping with intense cw dye lasers is discussed. The target density and electron spin polarization depend on the dye laser intensity and bandwidth, the magnetic field at the target, and the electron spin depolarization time. For example in a magnetic field of 1.5 x 10 3 G, and using 1 W dye laser with a bandwidth of 10 10 Hz one can construct an electron spin polarized Na vapor target with a target thickness of 1.6 x 10 13 atoms/cm 2 and an average electron spin polarization of about 90% even though the Na atoms are completely depolarized at every wall collision. Possible uses of the electron spin polarized targets for the production of intense beams of polarized H - or 3 He - ions are discussed. (orig.)

  18. Optically enhanced nuclear cross polarization in acridine-doped fluorene

    Energy Technology Data Exchange (ETDEWEB)

    Oshiro, C.M.

    1982-06-01

    The objective of this work has been to create large polarizations of the dilute /sup 13/C nuclei in the solid state. The idea was to create /sup 1/H polarizations larger than Boltzmann and to use the proton enhanced nuclear induction spectroscopy cross polarization technique to then transfer this large polarization to the /sup 13/C spin system. Optical Nuclear Polarization (ONP) of acridine-doped fluorene single crystals was studied. In addition, ONP of powdered samples of the acridine-doped fluorene was studied. In general, many compounds do not crystallize easily or do not form large crystals suitable for NMR experiments. Powdered, amorphous and randomly dispersed samples are generally far more readily available than single crystals. One objective of this work has been to (first) create large /sup 1/H polarizations. Although large optical proton polarizations in single crystals have been reported previously, optically generated polarizations in powdered samples have not been reported. For these reasons, ONP studies of powdered samples of the acridine-doped fluorene were also undertaken. Using ONP in combination with the proton enhanced nuclear induction spectroscopy experiment, large /sup 13/C polarizations have been created in fluorene single crystals. These large /sup 13/C polarizations have permitted the determination of the seven incongruent chemical shielding tensors of the fluorene molecule. Part 2 of this thesis describes the proton enhanced nuclear induction spectroscopy experiment. Part 3 describes the ONP experiment. Part 4 is a description of the experimental set-up. Part 5 describes the data analysis for the determination of the chemical shielding tensors. Part 6 presents the results of the ONP experiments performed in this work and the chemical shielding tensors determined.

  19. Optically enhanced nuclear cross polarization in acridine-doped fluorene

    International Nuclear Information System (INIS)

    Oshiro, C.M.

    1982-06-01

    The objective of this work has been to create large polarizations of the dilute 13 C nuclei in the solid state. The idea was to create 1 H polarizations larger than Boltzmann and to use the proton enhanced nuclear induction spectroscopy cross polarization technique to then transfer this large polarization to the 13 C spin system. Optical Nuclear Polarization (ONP) of acridine-doped fluorene single crystals was studied. In addition, ONP of powdered samples of the acridine-doped fluorene was studied. In general, many compounds do not crystallize easily or do not form large crystals suitable for NMR experiments. Powdered, amorphous and randomly dispersed samples are generally far more readily available than single crystals. One objective of this work has been to (first) create large 1 H polarizations. Although large optical proton polarizations in single crystals have been reported previously, optically generated polarizations in powdered samples have not been reported. For these reasons, ONP studies of powdered samples of the acridine-doped fluorene were also undertaken. Using ONP in combination with the proton enhanced nuclear induction spectroscopy experiment, large 13 C polarizations have been created in fluorene single crystals. These large 13 C polarizations have permitted the determination of the seven incongruent chemical shielding tensors of the fluorene molecule. Part 2 of this thesis describes the proton enhanced nuclear induction spectroscopy experiment. Part 3 describes the ONP experiment. Part 4 is a description of the experimental set-up. Part 5 describes the data analysis for the determination of the chemical shielding tensors. Part 6 presents the results of the ONP experiments performed in this work and the chemical shielding tensors determined

  20. Refractive index retrieving of polarization maintaining optical fibers

    Science.gov (United States)

    Ramadan, W. A.; Wahba, H. H.; Shams El-Din, M. A.; Abd El-Sadek, I. G.

    2018-01-01

    In this paper, the cross-section images, of two different types of polarization maintaining (PM) optical fibers, are employed to estimate the optical phase variation due to transverse optical rays passing through these optical fibers. An adaptive algorithm is proposed to recognize the different areas constituting the PM optical fibers cross-sections. These areas are scanned by a transverse beam to calculate the optical paths for given values of refractive indices. Consequently, the optical phases across the PM optical fibers could be recovered. PM optical fiber is immersed in a matching fluid and set in the object arm of Mach-Zehnder interferometer. The produced interferograms are analyzed to extract the optical phases caused by the PM optical fibers. The estimated optical phases could be optimized to be in good coincidence with experimentally extracted ones. This has been achieved through changing of the PM optical fibers refractive indices to retrieve the correct values. The correct refractive indices values are confirmed by getting the best fit between the estimated and the extracted optical phases. The presented approach is a promising one because it provides a quite direct and accurate information about refractive index, birefringence and beat length of PM optical fibers comparing with different techniques handle the same task.

  1. Polarization preserving ultra fast optical shutter for quantum information processing

    OpenAIRE

    Spagnolo, Nicolo'; Vitelli, Chiara; Giacomini, Sandro; Sciarrino, Fabio; De Martini, Francesco

    2008-01-01

    We present the realization of a ultra fast shutter for optical fields, which allows to preserve a generic polarization state, based on a self-stabilized interferometer. It exhibits high (or low) transmittivity when turned on (or inactive), while the fidelity of the polarization state is high. The shutter is realized through two beam displacing prisms and a longitudinal Pockels cell. This can represent a useful tool for controlling light-atom interfaces in quantum information processing.

  2. Optically pumped polarized alkali atomic beams and targets

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1984-01-01

    The optical pumping of 23 Na and 6 Li atomic beams is discussed. Experiments on the optical pumping of 23 Na atomic beams using either a single mode dye laser followed by a double passed acousto-optic modulator or a multimode dye laser are reported. The optical pumping of a 23 Na vapor target for use in a polarized H - ion source is discussed. Results on the use of viton as a wall coating with a long relaxation time are reported. 31 references, 6 figures, 3 tables

  3. Geometrically unrestricted, topologically constrained control of liquid crystal defects using simultaneous holonomic magnetic and holographic optical manipulation

    Science.gov (United States)

    Varney, Michael C. M.; Jenness, Nathan J.; Smalyukh, Ivan I.

    2014-02-01

    Despite the recent progress in physical control and manipulation of various condensed matter, atomic, and particle systems, including individual atoms and photons, our ability to control topological defects remains limited. Recently, controlled generation, spatial translation, and stretching of topological point and line defects have been achieved using laser tweezers and liquid crystals as model defect-hosting systems. However, many modes of manipulation remain hindered by limitations inherent to optical trapping. To overcome some of these limitations, we integrate holographic optical tweezers with a magnetic manipulation system, which enables fully holonomic manipulation of defects by means of optically and magnetically controllable colloids used as "handles" to transfer forces and torques to various liquid crystal defects. These colloidal handles are magnetically rotated around determined axes and are optically translated along three-dimensional pathways while mechanically attached to defects, which, combined with inducing spatially localized nematic-isotropic phase transitions, allow for geometrically unrestricted control of defects, including previously unrealized modes of noncontact manipulation, such as the twisting of disclination clusters. These manipulation capabilities may allow for probing topological constraints and the nature of defects in unprecedented ways, providing the foundation for a tabletop laboratory to expand our understanding of the role defects play in fields ranging from subatomic particle physics to early-universe cosmology.

  4. Design and calibration of a digital Fourier holographic microscope for particle sizing via goniometry and optical scatter imaging in transmission.

    Science.gov (United States)

    Rossi, Vincent M; Jacques, Steven L

    2016-06-13

    Goniometry and optical scatter imaging have been used for optical determination of particle size based upon optical scattering. Polystyrene microspheres in suspension serve as a standard for system validation purposes. The design and calibration of a digital Fourier holographic microscope (DFHM) are reported. Of crucial importance is the appropriate scaling of scattering angle space in the conjugate Fourier plane. A detailed description of this calibration process is described. Spatial filtering of the acquired digital hologram to use photons scattered within a restricted angular range produces an image. A pair of images, one using photons narrowly scattered within 8 - 15° (LNA), and one using photons broadly scattered within 8 - 39° (HNA), are produced. An image based on the ratio of these two images, OSIR = HNA/LNA, following Boustany et al. (2002), yields a 2D Optical Scatter Image (OSI) whose contrast is based on the angular dependence of photon scattering and is sensitive to the microsphere size, especially in the 0.5-1.0µm range. Goniometric results are also given for polystyrene microspheres in suspension as additional proof of principle for particle sizing via the DFHM.

  5. Ten per cent polarized optical emission from GRB 090102.

    Science.gov (United States)

    Steele, I A; Mundell, C G; Smith, R J; Kobayashi, S; Guidorzi, C

    2009-12-10

    The nature of the jets and the role of magnetic fields in gamma-ray bursts (GRBs) remains unclear. In a baryon-dominated jet only weak, tangled fields generated in situ through shocks would be present. In an alternative model, jets are threaded with large-scale magnetic fields that originate at the central engine and that accelerate and collimate the material. To distinguish between the models the degree of polarization in early-time emission must be measured; however, previous claims of gamma-ray polarization have been controversial. Here we report that the early optical emission from GRB 090102 was polarized at 10 +/- 1 per cent, indicating the presence of large-scale fields originating in the expanding fireball. If the degree of polarization and its position angle were variable on timescales shorter than our 60-second exposure, then the peak polarization may have been larger than ten per cent.

  6. The TRIUMF optically-pumped polarized H- ion source

    International Nuclear Information System (INIS)

    Levy, C.D.P.; Jayamanna, K.; McDonald, M.; Schmor, P.W.; Van Oers, W.T.H.; Welz, J.; Wight, G.W.; Dutto, G.; Zelenski, A.N.; Sakae, T.

    1995-09-01

    The TRIUMF dc optically-pumped polarized H - ion source (OPPIS) produces 200 μA dc H - current at 85% polarization within a normalized emittance (90%) of 0.8 π mm mrad, for operations at the TRIUMF cyclotron. As a result of development of the ECR primary proton source, 1.6 mA dc polarized H - current is produced within a normalized emittance of 2 π mm mrad, suitable for high energy accelerators. The OPPIS has also been developed for use in a parity non-conservation experiment which has very severe limits on permissible helicity-correlated changes in beam current and energy. (author)

  7. Zeno inhibition of polarization rotation in an optically active medium

    International Nuclear Information System (INIS)

    Gonzalo, Isabel; Luis, Alfredo; Porras, Miguel A

    2015-01-01

    We describe an experiment in which the rotation of the polarization of light propagating in an optically active water solution of D-fructose tends to be inhibited by frequent monitoring whether the polarization remains unchanged. This is an example of the Zeno effect that has remarkable pedagogical interest because of its conceptual simplicity, easy implementation, low cost, and because the same the Zeno effect holds at classical and quantum levels. An added value is the demonstration of the Zeno effect beyond typical idealized assumptions in a practical setting with real polarizers. (paper)

  8. Development of polarization magneto-optics of paramagnetic crystals

    International Nuclear Information System (INIS)

    Zapasskij, V.S.; Feofilov, P.P.

    1975-01-01

    The present status of the polarization magnetooptics of crystals containing paramagnetic ion impurities is reviewed. The paper discusses methods of measurement of circular magnetic anisotropy and results obtained in recent years in the field of conventional magnetooptical studies, e.g., magnetooptical activity in absorption spectra for intrinsic and impurity defects in crystals, luminescence magnetic circular polarization, anisotropy of magnetooptical activity in cubic crystals. The main emphasis is placed on new trends in polarization magnetooptics: studies of interactions of a spin system with a lattice, in particular, spin-lattice relaxation and spin memory effect, experiments in the double radiooptical resonance, studies of optical spin relaxation, nonlinear magnetooptical effects, etc

  9. The TRIUMF optically-pumped polarized H- ion source

    International Nuclear Information System (INIS)

    Levy, C.D.P.; Jayamanna, K.; McDonald, M.

    1995-09-01

    The TRIUMF dc optically-pumped polarized H - ion source (OPPIS) produces 200 microA dc H - current at 85% polarization within a normalized emittance (90%) of 0.8 π mm mrad, for operations at the TRIUMF cyclotron. As a result of development of the ECR primary proton source, 1.6 mA dc polarized H - current is produced within a normalized emittance of 2 π mm mrad, suitable for high energy accelerators. The OPPIS has also been developed for use in a parity non-conservation experiment which has very severe limits on permissible helicity-correlated changes in beam current and energy

  10. Optical polarization studies of Herbig-Haro objects: Pt. 5

    International Nuclear Information System (INIS)

    Scarrott, S.M.; Warren-Smith, R.F.

    1988-01-01

    Optical linear polarization maps are presented for the HH46/47 nebulosities in the ESO210-6A dark globule. HH46 is part of an optical bipolar nebula illuminated by an obscured source - HH46IRS. The polarization pattern in the immediate neighbourhood of the source suggests the presence of circumstellar disc oriented in such a manner that the well-collimated outflows propagate along the major axis of the disc before creating the Herbig-Haro knots HH47A/B/C on the periphery of the globule. (author)

  11. Optical polarization studies of Herbig-Haro objects: Pt. 4

    International Nuclear Information System (INIS)

    Scarrott, S.M.

    1988-01-01

    Optical polarization maps are presented for the various nebulosities of the HH34 complex in the L1641 dark cloud. The Herbig-Haro object HH34 and its associated optical jet are unpolarized but their source of excitation (HH34-IRS) is the illuminating star of a reflection nebula which envelops the jet and extends as far as HH34. The optical polarization of HH34-IRS suggests that it is surrounded by a circumstellar disc which collimates the outflows in some manner. There is other reflection nebulosity in the region illuminated by a faint star which we identify as the optical counterpart of HH34-IRS5. We have also discovered a small bipolar reflection nebula approximately 20 arcsec west of HH34-IRS. (author)

  12. Polarization-Insensitive Tunable Optical Filters based on Liquid Crystal Polarization Gratings

    Science.gov (United States)

    Nicolescu, Elena

    Tunable optical filters are widely used for a variety of applications including spectroscopy, optical communication networks, remote sensing, and biomedical imaging and diagnostics. All of these application areas can greatly benefit from improvements in the key characteristics of the tunable optical filters embedded in them. Some of these key parameters include peak transmittance, bandwidth, tuning range, and transition width. In recent years research efforts have also focused on miniaturizing tunable optical filters into physically small packages for compact portable spectroscopy and hyperspectral imaging applications such as real-time medical diagnostics and defense applications. However, it is important that miniaturization not have a detrimental effect on filter performance. The overarching theme of this dissertation is to explore novel configurations of Polarization Gratings (PGs) as simple, low-cost, polarization-insensitive alternatives to conventional optical filtering technologies for applications including hyperspectral imaging and telecommunications. We approach this goal from several directions with a combination of theory and experimental demonstration leading to, in our opinion, a significant contribution to the field. We present three classes of tunable optical filters, the first of which is an angle-filtering scheme where the stop-band wavelengths are redirected off axis and the passband is transmitted on-axis. This is achieved using a stacked configuration of polarization gratings of various thicknesses. To improve this class of filter, we also introduce a novel optical element, the Bilayer Polarization Grating, exhibiting unique optical properties and demonstrating complex anchoring conditions with high quality. The second class of optical filter is analogous to a Lyot filter, utilizing stacks of static or tunable waveplates sandwiched with polarizing elements. However, we introduce a new configuration using PGs and static waveplates to replace

  13. Polarized electrons and the origin of optical activity

    International Nuclear Information System (INIS)

    Bonner, W.A.; Dort, M.A. Van; Yearian, M.R.; Zeman, H.D.; Li, G.C.; Stanford Univ., Calif.

    1976-01-01

    The history of experiments bearing on the origin of optical acitivity in nature by parity non-conservation during the β-decay of radioactive isotopes is briefly reviewed. Following this, we present a more detailed description of our recent published and unpublished data and calculations regarding the generation of optical activity in DL-leucine by means of artificially produced longitudinally polarized electrons from a linear accelerator

  14. Optically compressed sensing by under sampling the polar Fourier plane

    International Nuclear Information System (INIS)

    Stern, A; Levi, O; Rivenson, Y

    2010-01-01

    In a previous work we presented a compressed imaging approach that uses a row of rotating sensors to capture indirectly polar strips of the Fourier transform of the image. Here we present further developments of this technique and present new results. The advantages of our technique, compared to other optically compressed imaging techniques, is that its optical implementation is relatively easy, it does not require complicate calibrations and that it can be implemented in near-real time.

  15. Optical polarization of high-energy BL Lacertae objects

    Science.gov (United States)

    Hovatta, T.; Lindfors, E.; Blinov, D.; Pavlidou, V.; Nilsson, K.; Kiehlmann, S.; Angelakis, E.; Fallah Ramazani, V.; Liodakis, I.; Myserlis, I.; Panopoulou, G. V.; Pursimo, T.

    2016-12-01

    Context. We investigate the optical polarization properties of high-energy BL Lac objects using data from the RoboPol blazar monitoring program and the Nordic Optical Telescope. Aims: We wish to understand if there are differences between the BL Lac objects that have been detected with the current-generation TeV instruments and those objects that have not yet been detected. Methods: We used a maximum-likelihood method to investigate the optical polarization fraction and its variability in these sources. In order to study the polarization position angle variability, we calculated the time derivative of the electric vector position angle (EVPA) change. We also studied the spread in the Stokes Q/I-U/I plane and rotations in the polarization plane. Results: The mean polarization fraction of the TeV-detected BL Lacs is 5%, while the non-TeV sources show a higher mean polarization fraction of 7%. This difference in polarization fraction disappears when the dilution by the unpolarized light of the host galaxy is accounted for. The TeV sources show somewhat lower fractional polarization variability amplitudes than the non-TeV sources. Also the fraction of sources with a smaller spread in the Q/I-U/I plane and a clumped distribution of points away from the origin, possibly indicating a preferred polarization angle, is larger in the TeV than in the non-TeV sources. These differences between TeV and non-TeV samples seem to arise from differences between intermediate and high spectral peaking sources instead of the TeV detection. When the EVPA variations are studied, the rate of EVPA change is similar in both samples. We detect significant EVPA rotations in both TeV and non-TeV sources, showing that rotations can occur in high spectral peaking BL Lac objects when the monitoring cadence is dense enough. Our simulations show that we cannot exclude a random walk origin for these rotations. Conclusions: These results indicate that there are no intrinsic differences in the

  16. Generation and propagation of radially polarized beams in optical fibers

    DEFF Research Database (Denmark)

    Ramachandran, Siddharth; Kristensen, P; Yan, M F

    2009-01-01

    Beams with polarization singularities have attracted immense recent attention in a wide array of scientific and technological disciplines. We demonstrate a class of optical fibers in which these beams can be generated and propagated over long lengths with unprecedented stability, even...

  17. Nonvolatile Rad-Hard Holographic Memory

    Science.gov (United States)

    Chao, Tien-Hsin; Zhou, Han-Ying; Reyes, George; Dragoi, Danut; Hanna, Jay

    2001-01-01

    We are investigating a nonvolatile radiation-hardened (rad-hard) holographic memory technology. Recently, a compact holographic data storage (CHDS) breadboard utilizing an innovative electro-optic scanner has been built and demonstrated for high-speed holographic data storage and retrieval. The successful integration of this holographic memory breadboard has paved the way for follow-on radiation resistance test of the photorefractive (PR) crystal, Fe:LiNbO3. We have also started the investigation of using two-photon PR crystals that are doubly doped with atoms of iron group (Ti, Cr, Mn, Cu) and of rare-earth group (Nd, Tb) for nonvolatile holographic recordings.

  18. Fiber-optic polarization diversity detection for rotary probe optical coherence tomography.

    Science.gov (United States)

    Lee, Anthony M D; Pahlevaninezhad, Hamid; Yang, Victor X D; Lam, Stephen; MacAulay, Calum; Lane, Pierre

    2014-06-15

    We report a polarization diversity detection scheme for optical coherence tomography with a new, custom, miniaturized fiber coupler with single mode (SM) fiber inputs and polarization maintaining (PM) fiber outputs. The SM fiber inputs obviate matching the optical lengths of the X and Y OCT polarization channels prior to interference and the PM fiber outputs ensure defined X and Y axes after interference. Advantages for this scheme include easier alignment, lower cost, and easier miniaturization compared to designs with free-space bulk optical components. We demonstrate the utility of the detection system to mitigate the effects of rapidly changing polarization states when imaging with rotating fiber optic probes in Intralipid suspension and during in vivo imaging of human airways.

  19. Optical polarization studies of Herbig-Haro objects. Pt. 7

    International Nuclear Information System (INIS)

    Scarrott, S.M.; Gledhill, T.M.; Rolph, C.D.

    1990-01-01

    A small patch of optical nebulosity in the cometary globule CG30 is an amorphous reflection nebula containing a Herbig-Haro knot. The exciting and illuminating star, which we identify with the IR source IRAS 08076-3356/CG30IRS4, is deeply embedded in the globule and is not seen directly at optical wavelengths. Structure in the polarization data suggests that the optical nebula is formed by the illumination of the walls of a cavity excavated in the cloud during outflow activity from the embedded source. (author)

  20. Influences of optical elements on the polarization measurement

    International Nuclear Information System (INIS)

    Goto, M.; Hayakawa, M.; Atake, M.; Iwamae, A.

    2004-01-01

    An emission line of He I λ 667.8 nm is observed and the Large Helical Device (LHD) with a polarimeter, with which two linearly polarized components if the light from the same line of sight is simultaneously measured. The emission line exhibits splitting due to the normal Zeeman effect and the π and σ lights are respectively observed. The results indicate the polarization state of emission lines is different from our expectation. From two measurements, for the second of which the polarimeter is rotated 45 degrees form the first, the polarization ellipses of all the three polarized lights are determined. Some observations for a reversed magnetic field plasma operation, for different emission lines of different ions, and also for operation with some different magnetic field strengths suggest that the distortion state originates not in the atomic radiation itself or the plasma condition, but in the optical window at the observation port of the vacuum chamber. (author)

  1. Operation of the optically pumped polarized H- source at LAMPF

    International Nuclear Information System (INIS)

    York, R.L.; Tupa, D.; Swenson, D.R.; van Dyck, O.B.

    1991-01-01

    We report on the first five months of operation of the Optically Pumped Polarized Ion Source (OPPIS) for the nuclear physics research program at LAMPF. The LAMPF OPPIS is unique in using Ti: Sapphire lasers to polarize the potassium charge-exchange medium, and until recently was unique in using a superconducting magnet in the ECR source and polarizer regions. The ECR extraction electrode biasing arrangement is also unique. Typical performance was 25 microamps of peak current (measured at 750 keV) with 55% beam polarization or 15 microamps at 62%. Ion source availability was greater than 90%. We also report our planned improvements in preparation for research operation in May of 1991. 3 refs., 4 figs

  2. Holographic memories

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Berg, R.H.; Hvilsted, Søren

    1999-01-01

    A Two-dimensional holographic memory for archival storage is described. Assuming a coherent transfer function, an A4 page can be stored at high resolution in an area of 1 mm(2). Recently developed side-chain liquid crystalline azobenzene polyesters are found to be suitable media for holographic...

  3. In situ single-atom array synthesis using dynamic holographic optical tweezers

    Science.gov (United States)

    Kim, Hyosub; Lee, Woojun; Lee, Han-gyeol; Jo, Hanlae; Song, Yunheung; Ahn, Jaewook

    2016-01-01

    Establishing a reliable method to form scalable neutral-atom platforms is an essential cornerstone for quantum computation, quantum simulation and quantum many-body physics. Here we demonstrate a real-time transport of single atoms using holographic microtraps controlled by a liquid-crystal spatial light modulator. For this, an analytical design approach to flicker-free microtrap movement is devised and cold rubidium atoms are simultaneously rearranged with 2N motional degrees of freedom, representing unprecedented space controllability. We also accomplish an in situ feedback control for single-atom rearrangements with the high success rate of 99% for up to 10 μm translation. We hope this proof-of-principle demonstration of high-fidelity atom-array preparations will be useful for deterministic loading of N single atoms, especially on arbitrary lattice locations, and also for real-time qubit shuttling in high-dimensional quantum computing architectures. PMID:27796372

  4. Simulation of Terahertz Frequency Sources. Polar-Optical Phonon Enhancement of Harmonic Generation in Schottky Diodes

    National Research Council Canada - National Science Library

    Gelmont, Boris

    2002-01-01

    ... polar optical vibration frequency When a high frequency input signal is applied to a frequency multiplier device polar-optical phonons can enhance the non-linearities inherent in this device, enabling...

  5. Polarization holograms in a bifunctional amorphous polymer exhibiting equal values of photoinduced linear and circular birefringences.

    Science.gov (United States)

    Provenzano, Clementina; Pagliusi, Pasquale; Cipparrone, Gabriella; Royes, Jorge; Piñol, Milagros; Oriol, Luis

    2014-10-09

    Light-controlled molecular alignment is a flexible and useful strategy introducing novelty in the fields of mechanics, self-organized structuring, mass transport, optics, and photonics and addressing the development of smart optical devices. Azobenzene-containing polymers are well-known photocontrollable materials with large and reversible photoinduced optical anisotropies. The vectorial holography applied to these materials enables peculiar optical devices whose properties strongly depend on the relative values of the photoinduced birefringences. Here is reported a polarization holographic recording based on the interference of two waves with orthogonal linear polarization on a bifunctional amorphous polymer that, exceptionally, exhibits equal values of linear and circular birefringence. The peculiar photoresponse of the material coupled with the holographic technique demonstrates an optical device capable of decomposing the light into a set of orthogonally polarized linear components. The holographic structures are theoretically described by the Jones matrices method and experimentally investigated.

  6. Polarization sensitive optical coherence tomography in dentistry

    International Nuclear Information System (INIS)

    Dichtl, S.

    1998-01-01

    Optical coherence tomography (OCT) is a noninvasive and noncontact technique for obtaining cross-sectional images of biologic structure, which was initially introduced to depict the transparent tissue of the eye. It employs the partial coherence properties of a light source to image structures with high resolution (< 20 (m). Recently, this technique has also been applied in turbid media. This tomographic imaging is analogous to conventional ultrasound B mode imaging, except that OCT measures the intensity of backreflected infrared light rather than acoustical waves. First applications, of OCT in dentistry for diagnosing periodontal disease have been reported by Colston et al. presenting in vitro OCT images of the dental and periodontal tissues of porcine premolar teeth. In this work, the feasibility of polarisation sensitive OCT for dental material is suggested. In contrast with conventional OCT, where the magnitude of backscattered light as a function of depth is imaged, backscattered light is used to image the magnitude of the birefringence in the sample as a function of depth. Partial loss of birefringence is known to be an early indication of incipient caries or tissue thermal damage. Applying this technique for caries diagnosis or guidance regarding optimal dosimetry for thermally mediated laser therapeutic procedures, polarisation sensitive OCT would represent a promising new technology for dentistry. (author)

  7. Cantilever biosensor reader using a common-path, holographic optical interferometer

    DEFF Research Database (Denmark)

    Pedersen, Henrik Chresten; Jakobsen, Michael Linde; Hanson, Steen Grüner

    2010-01-01

    We demonstrate an optical reader principle aimed at monitoring biologically induced deflections of microcantilevers often used in biosensor systems. The principle is based on a so-called common-path optical interferometer in which the two interfering optical beams are copropagating,which makes...

  8. Semiconductor sensor for optically measuring polarization rotation of optical wavefronts using rare earth iron garnets

    Science.gov (United States)

    Duncan, Paul G.

    2002-01-01

    Described are the design of a rare earth iron garnet sensor element, optical methods of interrogating the sensor element, methods of coupling the optical sensor element to a waveguide, and an optical and electrical processing system for monitoring the polarization rotation of a linearly polarized wavefront undergoing external modulation due to magnetic field or electrical current fluctuation. The sensor element uses the Faraday effect, an intrinsic property of certain rare-earth iron garnet materials, to rotate the polarization state of light in the presence of a magnetic field. The sensor element may be coated with a thin-film mirror to effectively double the optical path length, providing twice the sensitivity for a given field strength or temperature change. A semiconductor sensor system using a rare earth iron garnet sensor element is described.

  9. Optical studies of polarized-electron-noble-gas collisions

    International Nuclear Information System (INIS)

    Gay, T.I.; Furst, J.E.; Geesmann, H.; Khakoo, M.A.; Madison, D.H.; Wijayaratna, W.M.K.P.; Bartschat, K.

    1992-01-01

    We have measured the Stoke's parameters of light emitted following impact excitation of He and Xe by transversely-polarized electrons. For He, the 2 3 S-3 3 P, 389 nm transition was studied in an effort to systematically develop a highly accurate optical electron polarimeter. The 6 3 P 2 -6 3 D 3 , 882 nm transition in Xe was used to assess the importance of spin-dependent forces on the continuum electron for this target. We attempted (and failed) to made the first optical observations of Mott scattering. (Author)

  10. Optical polarization studies of Herbig-Haro objects: Pt. 6

    International Nuclear Information System (INIS)

    Rolph, C.D.; Scarrott, S.M.

    1990-01-01

    An optical polarization map of the HH83 nebulosity on the periphery of the L1641 dark cloud in Orion shows that it is predominantly a reflection nebula illuminated by a nearby IR source (HH83IRS/IRAS 05311 - 0631) with no optical counterpart. The stellar jet is unpolarized as expected for an emission-line feature. The nebula has many morphological similarities to other pre-main-sequence nebulae such as Haro 6-5, L1551/IRS5, HH34 and Re50. (author)

  11. Performance optimization in mass production of volume holographic optical elements (vHOEs) using Bayfol HX photopolymer film

    Science.gov (United States)

    Bruder, Friedrich-Karl; Fäcke, Thomas; Grote, Fabian; Hagen, Rainer; Hönel, Dennis; Koch, Eberhard; Rewitz, Christian; Walze, Günther; Wewer, Brita

    2017-05-01

    Volume Holographic Optical Elements (vHOEs) gained wide attention as optical combiners for the use in smart glasses and augmented reality (SG and AR, respectively) consumer electronics and automotive head-up display applications. The unique characteristics of these diffractive grating structures - being lightweight, thin and flat - make them perfectly suitable for use in integrated optical components like spectacle lenses and car windshields. While being transparent in Off-Bragg condition, they provide full color capability and adjustable diffraction efficiency. The instant developing photopolymer Bayfol® HX film provides an ideal technology platform to optimize the performance of vHOEs in a wide range of applications. Important for any commercialization are simple and robust mass production schemes. In this paper, we present an efficient and easy to control one-beam recording scheme to copy a so-called master vHOE in a step-and-repeat process. In this contact-copy scheme, Bayfol® HX film is laminated to a master stack before being exposed by a scanning laser line. Subsequently, the film is delaminated in a controlled fashion and bleached. We explain working principles of the one-beam copy concept, discuss the opto-mechanical construction and outline the downstream process of the installed vHOE replication line. Moreover, we focus on aspects like performance optimization of the copy vHOE, the bleaching process and the suitable choice of protective cover film in the re-lamination step, preparing the integration of the vHOE into the final device.

  12. Simulations and experiments on polarization squeezing in optical fiber

    DEFF Research Database (Denmark)

    Corney, J.F.; Heersink, J.; Dong, R.

    2008-01-01

    We investigate polarization squeezing of ultrashort pulses in optical fiber, over a wide range of input energies and fiber lengths. Comparisons are made between experimental data and quantum dynamical simulations to find good quantitative agreement. The numerical calculations, performed using both...... effects cause a marked deterioration of squeezing at higher energies and longer fiber lengths. We also calculate the optimum fiber length for maximum squeezing....

  13. Regional polarization sensitivity of articular cartilage by using polarization sensitive optical coherence tomography

    Science.gov (United States)

    Xie, Tuqiang; Guo, Shuguang; Chen, Zhongping; Peavy, George M.

    2007-02-01

    In this study, PS-OCT is used to image fresh bovine joints to investigate the orientation of collagen fibrils in relation to optical phase retardation to better understand the distribution of normal matrix orientation and articular cartilage birefringence in different regions of a whole joint. Understanding and mapping variations in matrix organization and orientation within the normal joint is an important issue in potential applications of PS-OCT for evaluation and diagnosis of degenerative joint disease (DJD). The experimental results demonstrate that articular cartilage is not polarization sensitive on the edge of the medial, but polarization sensitive on the lateral edge of the tibial plateau. The collagen orientation on the edge of the joint is different from the central areas of the joint. Normal articular cartilage demonstrates regional polarization sensitivity within joints that is important to understand in order to accurately assess cartilage health by PS-OCT.

  14. Using wire shaping techniques and holographic optics to optimize deposition characteristics in wire-based laser cladding.

    Science.gov (United States)

    Goffin, N J; Higginson, R L; Tyrer, J R

    2016-12-01

    In laser cladding, the potential benefits of wire feeding are considerable. Typical problems with the use of powder, such as gas entrapment, sub-100% material density and low deposition rate are all avoided with the use of wire. However, the use of a powder-based source material is the industry standard, with wire-based deposition generally regarded as an academic curiosity. This is because, although wire-based methods have been shown to be capable of superior quality results, the wire-based process is more difficult to control. In this work, the potential for wire shaping techniques, combined with existing holographic optical element knowledge, is investigated in order to further improve the processing characteristics. Experiments with pre-placed wire showed the ability of shaped wire to provide uniformity of wire melting compared with standard round wire, giving reduced power density requirements and superior control of clad track dilution. When feeding with flat wire, the resulting clad tracks showed a greater level of quality consistency and became less sensitive to alterations in processing conditions. In addition, a 22% increase in deposition rate was achieved. Stacking of multiple layers demonstrated the ability to create fully dense, three-dimensional structures, with directional metallurgical grain growth and uniform chemical structure.

  15. Optical manipulation of aerosol droplets using a holographic dual and single beam trap

    Czech Academy of Sciences Publication Activity Database

    Brzobohatý, Oto; Šiler, Martin; Ježek, Jan; Jákl, Petr; Zemánek, Pavel

    2013-01-01

    Roč. 38, č. 22 (2013), s. 4601-4604 ISSN 0146-9592 R&D Projects: GA ČR GPP205/11/P294; GA ČR GPP205/12/P868; GA MŠk LH12018; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : optical tweezers * optical manipulation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.179, year: 2013

  16. Polarization diversity scheme on spectral polarization coding optical code-division multiple-access network

    Science.gov (United States)

    Yen, Chih-Ta; Huang, Jen-Fa; Chang, Yao-Tang; Chen, Bo-Hau

    2010-12-01

    We present an experiment demonstrating the spectral-polarization coding optical code-division multiple-access system introduced with a nonideal state of polarization (SOP) matching conditions. In the proposed system, the encoding and double balanced-detection processes are implemented using a polarization-diversity scheme. Because of the quasiorthogonality of Hadamard codes combining with array waveguide grating routers and a polarization beam splitter, the proposed codec pair can encode-decode multiple code words of Hadamard code while retaining the ability for multiple-access interference cancellation. The experimental results demonstrate that when the system is maintained with an orthogonal SOP for each user, an effective reduction in the phase-induced intensity noise is obtained. The analytical SNR values are found to overstate the experimental results by around 2 dB when the received effective power is large. This is mainly limited by insertion losses of components and a nonflattened optical light source. Furthermore, the matching conditions can be improved by decreasing nonideal influences.

  17. Holographic reconstruction of sound fields based on the acousto-optic effect

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Torras Rosell, Antoni; Jacobsen, Finn

    2013-01-01

    Recent studies have shown that it is possible to measure a sound field using acousto-optic tomography. Theacousto-optic effect, i.e., the interaction between sound and light, can be used to measure an arbitrary soundfield by scanning it with a laser Doppler vibrometer (LDV) over an aperture; This...

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

    Directory of Open Access Journals (Sweden)

    Virginijus Barzda

    2013-09-01

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

  19. Advanced Holographic Phase Nulls Suitable for EUV Quality Optical Testing, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A number of future space sciences missions require optical surfaces that are accurate to nanometer and sub-nanometer levels. These applications include large...

  20. Enhancement of the optical image with a DC blocked spiral holographic pattern

    International Nuclear Information System (INIS)

    Hwang, Sung-In; Lee, Jung-Kyun; Song, Dong-Hoon; Choi, Dae-Sik; Ko, Do-Kyeong

    2011-01-01

    A modification of microscopy using a spiral phase plate, which enhanced the optical image by blocking the DC part of the object spectrum is presented. In conventional differential-interference-contrast microscopy, enhancement of optical images is achieved by interference of mutual coherent beams which experience different optical phases. This method increases the contrast of the optical image compared to normal microscopy, but the image still has some blurring around the edge of the sample. Our modification consists of placing a DC blocking region on an optical spatial filter, which allows us to achieve a sharp edge compared to the conventional one. By patterning the grating of the circular area in the center with a different direction (π/4 in our case), we could redirect the DC part of the Fourier component that passed through the center of the phase plate. By eliminating the DC part of the object spectrum, we could get a highly enhanced image and clearly observed the inside of the cheek cell, which was invisible otherwise.

  1. Visualization of polarization state and its application in optics classroom teaching

    Science.gov (United States)

    Lei, Bing; Liu, Wei; Shi, Jianhua; Wang, Wei; Yao, Tianfu; Liu, Shugang

    2017-08-01

    Polarization of light and the related knowledge are key and difficult points in optical teaching, and they are difficult to be understood since they are very abstract concepts. To help students understand the polarization properties of light, some classroom demonstration experiments have been constructed by employing the optical source, polarizers, wave plates optical cage system and polarization axis finder (PAF). The PAF is a polarization indicating device with many linear polarizing components concentric circles, which can visualize the polarization axis's direction of linearly polarized light intuitively. With the help of these demonstration experiment systems, the conversion and difference between the linear polarized light and circularly polarized light have been observed directly by inserting or removing a quarter-wave plate. The rotation phenomenon of linearly polarized light's polarization axis when it propagates through an optical active medium has been observed and studied in experiment, and the strain distribution of some mounted and unmounted lenses have also been demonstrated and observed in experiment conveniently. Furthermore, some typical polarization targets, such as liquid crystal display (LCD), polarized dark glass and skylight, have been observed based on PAF, which is quite suitable to help students understand these targets' polarization properties and the related physical laws. Finally, these demonstration experimental systems have been employed in classroom teaching of our university in physical optics, optoelectronics and photoelectric detection courses, and they are very popular with teachers and students.

  2. Holographic Raman lidar

    International Nuclear Information System (INIS)

    Andersen, G.

    2000-01-01

    Full text: We have constructed a Raman lidar system that incorporates a holographic optical element. By resolving just 3 nitrogen lines in the Resonance Raman spectroscopy (RRS) spectrum, temperature fits as good as 1% at altitudes of 20km can be made in 30 minutes. Due to the narrowband selectivity of the HOE, the lidar provides measurements over a continuous 24hr period. By adding a 4th channel to capture the Rayleigh backscattered light, temperature profiles can be extended to 80km

  3. Trinary optical logic processors using shadow casting with polarized light

    Science.gov (United States)

    Ghosh, Amal K.; Basuray, A.

    1990-10-01

    An optical implementation is proposed of the modified trinary number (MTN) system (Datta et al., 1989) in which any binary number can have arithmetic operations performed on it in parallel without the need for carry and borrow steps. The present method extends the lensless shadow-casting technique of Tanida and Ichioka (1983, 1985). Three kinds of spatial coding are used for encoding the trinary input states, whereas in the decoding plane three states are identified by no light and light with two orthogonal states of polarization.

  4. Nonlinear optical polarization analysis in chemistry and biology

    CERN Document Server

    Simpson, Garth J

    2017-01-01

    This rigorous yet accessible guide presents a molecular-based description of nonlinear optical polarization analysis of chemical and biological assemblies. It includes discussion of the most common nonlinear optical microscopy and interfacial measurements used for quantitative analysis, specifically second harmonic generation (SHG), two-photon excited fluorescence (2PEF), vibrational sum frequency generation (SFG), and coherent anti-Stokes Raman spectroscopy/stimulated Raman spectroscopy (CARS/SRS). A linear algebra mathematical framework is developed, allowing step-wise systematic connections to be made between the observable measurements and the molecular response. Effects considered include local field corrections, the molecular orientation distribution, rotations between the molecular frame, the local frame and the laboratory frame, and simplifications from molecular and macromolecular symmetry. Specific examples are provided throughout the book, working from the common and relatively simple case studies ...

  5. Polarization mode dispersion in optical fiber transmission systems

    Science.gov (United States)

    Cameron, John Charles

    The birefringence of optical fibers causes pulse broadening in fiber-optic communication systems. This phenomenon is known as polarization mode dispersion (PMD). PMD is one of the most important limiting factors for high capacity fiber-optic systems. A number of aspects of PMD are examined in this thesis. In Chapter 2 an expression is derived for the probability density function of the pulse broadening due to first-order PMD. This result is used to obtain an expression for the system limitation due to PMD. The birefringence of optical fibers is commonly simulated with the waveplate model. In Chapter 3 two standard versions of the waveplate model are introduced. In addition, a novel waveplate model is proposed. The characteristics of the three versions of the waveplate model are examined to confirm their suitability for use in subsequent chapters of the thesis. Simulations with the waveplate model are performed in Chapter 4 for three purposes: (1) to determine the impact of chromatic dispersion on the system limitation due to PMD, (2) to examine the effectiveness of three different PMD compensation techniques in the presence of chromatic dispersion, and (3) to examine the interaction of second-order chromatic dispersion with PMD. The simulations in Chapter 4 reveal that it is possible with one compensation technique to have output pulses that are narrower than the input pulses. In Chapter 5, this anomalous pulse narrowing is demonstrated analytically for a simple model of PMD and through experiment. It is also shown that this pulse narrowing can be explained as an interference phenomenon. Chapter 6 presents measurements of PMD and state of polarization on installed optical fibers. The PMD coefficients of 122 fibers are presented and the results are analyzed in terms of the age of the fibers and the type of cabling. Measurements of the time evolution of PMD and state of polarization are presented for fibers installed in both buried and aerial cables. The uncertainty

  6. All-optical clocked flip-flops and random access memory cells using the nonlinear polarization rotation effect of low-polarization-dependent semiconductor optical amplifiers

    Science.gov (United States)

    Wang, Yongjun; Liu, Xinyu; Tian, Qinghua; Wang, Lina; Xin, Xiangjun

    2018-03-01

    Basic configurations of various all-optical clocked flip-flops (FFs) and optical random access memory (RAM) based on the nonlinear polarization rotation (NPR) effect of low-polarization-dependent semiconductor optical amplifiers (SOA) are proposed. As the constituent elements, all-optical logic gates and all-optical SR latches are constructed by taking advantage of the SOA's NPR switch. Different all-optical FFs (AOFFs), including SR-, D-, T-, and JK-types as well as an optical RAM cell were obtained by the combination of the proposed all-optical SR latches and logic gates. The effectiveness of the proposed schemes were verified by simulation results and demonstrated by a D-FF and 1-bit RAM cell experimental system. The proposed all-optical clocked FFs and RAM cell are significant to all-optical signal processing.

  7. The RINGO2 and DIPOL optical polarization catalogue of blazars

    Science.gov (United States)

    Jermak, H.; Steele, I. A.; Lindfors, E.; Hovatta, T.; Nilsson, K.; Lamb, G. P.; Mundell, C.; Barres de Almeida, U.; Berdyugin, A.; Kadenius, V.; Reinthal, R.; Takalo, L.

    2016-11-01

    We present ˜2000 polarimetric and ˜3000 photometric observations of 15 γ-ray bright blazars over a period of 936 days (2008-10-11 to 2012-10-26) using data from the Tuorla blazar monitoring program (KVA DIPOL) and Liverpool Telescope (LT) RINGO2 polarimeters (supplemented with data from SkyCamZ (LT) and Fermi-LAT γ-ray data). In 11 out of 15 sources we identify a total of 19 electric vector position angle (EVPA) rotations and 95 flaring episodes. We group the sources into subclasses based on their broad-band spectral characteristics and compare their observed optical and γ-ray properties. We find that (1) the optical magnitude and γ-ray flux are positively correlated, (2) EVPA rotations can occur in any blazar subclass, four sources show rotations that go in one direction and immediately rotate back, (3) we see no difference in the γ-ray flaring rates in the sample; flares can occur during and outside of rotations with no preference for this behaviour, (4) the average degree of polarization (DoP), optical magnitude and γ-ray flux are lower during an EVPA rotation compared with during non-rotation and the distribution of the DoP during EVPA rotations is not drawn from the same parent sample as the distribution outside rotations, (5) the number of observed flaring events and optical polarization rotations are correlated, however we find no strong evidence for a temporal association between individual flares and rotations and (6) the maximum observed DoP increases from ˜10 per cent to ˜30 per cent to ˜40 per cent for subclasses with synchrotron peaks at high, intermediate and low frequencies, respectively.

  8. Holographic line field en-face OCT with digital adaptive optics in the retina in vivo.

    Science.gov (United States)

    Ginner, Laurin; Schmoll, Tilman; Kumar, Abhishek; Salas, Matthias; Pricoupenko, Nastassia; Wurster, Lara M; Leitgeb, Rainer A

    2018-02-01

    We demonstrate a high-resolution line field en-face time domain optical coherence tomography (OCT) system using an off-axis holography configuration. Line field en-face OCT produces high speed en-face images at rates of up to 100 Hz. The high frame rate favors good phase stability across the lateral field-of-view which is indispensable for digital adaptive optics (DAO). Human retinal structures are acquired in-vivo with a broadband light source at 840 nm, and line rates of 10 kHz to 100 kHz. Structures of different retinal layers, such as photoreceptors, capillaries, and nerve fibers are visualized with high resolution of 2.8 µm and 5.5 µm in lateral directions. Subaperture based DAO is successfully applied to increase the visibility of cone-photoreceptors and nerve fibers. Furthermore, en-face Doppler OCT maps are generated based on calculating the differential phase shifts between recorded lines.

  9. All fiber optics circular-state swept source polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Lin, Hermann; Kao, Meng-Chun; Lai, Chih-Ming; Huang, Jyun-Cin; Kuo, Wen-Chuan

    2014-02-01

    A swept source (SS)-based circular-state (CS) polarization-sensitive optical coherence tomography (PS-OCT) constructed entirely with polarization-maintaining fiber optics components is proposed with the experimental verification. By means of the proposed calibration scheme, bulk quarter-wave plates can be replaced by fiber optics polarization controllers to, therefore, realize an all-fiber optics CS SSPS-OCT. We also present a numerical dispersion compensation method, which can not only enhance the axial resolution, but also improve the signal-to-noise ratio of the images. We demonstrate that this compact and portable CS SSPS-OCT system with an accuracy comparable to bulk optics systems requires less stringent lens alignment and can possibly serve as a technology to realize PS-OCT instrument for clinical applications (e.g., endoscopy). The largest deviations in the phase retardation (PR) and fast-axis (FA) angle due to sample probe in the linear scanning and a rotation angle smaller than 65 deg were of the same order as those in stationary probe setups. The influence of fiber bending on the measured PR and FA is also investigated. The largest deviations of the PR were 3.5 deg and the measured FA change by ~12 to 21 deg. Finally, in vivo imaging of the human fingertip and nail was successfully demonstrated with a linear scanning probe.

  10. Structured caustic vector vortex optical field: manipulating optical angular momentum flux and polarization rotation.

    Science.gov (United States)

    Chen, Rui-Pin; Chen, Zhaozhong; Chew, Khian-Hooi; Li, Pei-Gang; Yu, Zhongliang; Ding, Jianping; He, Sailing

    2015-05-29

    A caustic vector vortex optical field is experimentally generated and demonstrated by a caustic-based approach. The desired caustic with arbitrary acceleration trajectories, as well as the structured states of polarization (SoP) and vortex orders located in different positions in the field cross-section, is generated by imposing the corresponding spatial phase function in a vector vortex optical field. Our study reveals that different spin and orbital angular momentum flux distributions (including opposite directions) in different positions in the cross-section of a caustic vector vortex optical field can be dynamically managed during propagation by intentionally choosing the initial polarization and vortex topological charges, as a result of the modulation of the caustic phase. We find that the SoP in the field cross-section rotates during propagation due to the existence of the vortex. The unique structured feature of the caustic vector vortex optical field opens the possibility of multi-manipulation of optical angular momentum fluxes and SoP, leading to more complex manipulation of the optical field scenarios. Thus this approach further expands the functionality of an optical system.

  11. Polarization sensitive optical coherence tomography in equine bone

    Science.gov (United States)

    Jacobs, J. W.; Matcher, S. J.

    2009-02-01

    Optical coherence tomography (OCT) has been used to image equine bone samples. OCT and polarization sensitive OCT (PS-OCT) images of equine bone samples, before and after demineralization, are presented. Using a novel approach, taking a series of images at different angles of illumination, the polar angle and true birefringence of collagen within the tissue is determined, at one site in the sample. The images were taken before and after the bones were passed through a demineralization process. The images show an improvement in depth penetration after demineralization allowing better visualization of the internal structure of the bone and the optical orientation of the collagen. A quantitative measurement of true birefringence has been made of the bone; true birefringence was shown to be 1.9x10-3 before demineralization increasing to 2.7x10-3 after demineralization. However, determined collagen fiber orientation remains the same before and after demineralization. The study of bone is extensive within the field of tissue engineering where an understanding of the internal structures is essential. OCT in bone, and improved depth penetration through demineralization, offers a useful approach to bone analysis.

  12. Reversible optical control of macroscopic polarization in ferroelectrics

    Science.gov (United States)

    Rubio-Marcos, Fernando; Ochoa, Diego A.; Del Campo, Adolfo; García, Miguel A.; Castro, Germán R.; Fernández, José F.; García, José E.

    2018-01-01

    The optical control of ferroic properties is a subject of fascination for the scientific community, because it involves the establishment of new paradigms for technology1-9. Domains and domain walls are known to have a great impact on the properties of ferroic materials1-24. Progress is currently being made in understanding the behaviour of the ferroelectric domain wall, especially regarding its dynamic control10-12,17,19. New research is being conducted to find effective methodologies capable of modulating ferroelectric domain motion for future electronics. However, the practical use of ferroelectric domain wall motion should be both stable and reversible (rewritable) and, in particular, be able to produce a macroscopic response that can be monitored easily12,17. Here, we show that it is possible to achieve a reversible optical change of ferroelectric domains configuration. This effect leads to the tuning of macroscopic polarization and its related properties by means of polarized light, a non-contact external control. Although this is only the first step, it nevertheless constitutes the most crucial one in the long and complex process of developing the next generation of photo-stimulated ferroelectric devices.

  13. Physical optics in the factory works - holographic quality and safety tests with a laser and a thermoplast

    International Nuclear Information System (INIS)

    Lhotzky, A.

    1982-01-01

    Using holographic methods, the quality of bonds between various materials can be tested. The measuring method is explained using the aeroplane tyre test which is particularly important for practical use. The method can also be used for parts where faulty parts deform in a different way to fault-free parts. The deformations used for the test lie in the micron range. A second important field of use is the vibration analysis. Here the hologrammes show weak points in the construction and indicate to the designer the way to design optimization. Noise sources can also be detected with the holographic vibration analysis. The most important novelty in the holographic testing methods was made by the thermoplast film which makes possible the obtaining of instant hologrammes and thus automatic running of the test. (orig.) [de

  14. Circularly polarized near-field optical mapping of spin-resolved quantum Hall chiral edge states.

    Science.gov (United States)

    Mamyouda, Syuhei; Ito, Hironori; Shibata, Yusuke; Kashiwaya, Satoshi; Yamaguchi, Masumi; Akazaki, Tatsushi; Tamura, Hiroyuki; Ootuka, Youiti; Nomura, Shintaro

    2015-04-08

    We have successfully developed a circularly polarized near-field scanning optical microscope (NSOM) that enables us to irradiate circularly polarized light with spatial resolution below the diffraction limit. As a demonstration, we perform real-space mapping of the quantum Hall chiral edge states near the edge of a Hall-bar structure by injecting spin polarized electrons optically at low temperature. The obtained real-space mappings show that spin-polarized electrons are injected optically to the two-dimensional electron layer. Our general method to locally inject spins using a circularly polarized NSOM should be broadly applicable to characterize a variety of nanomaterials and nanostructures.

  15. Polarization tracking system for free-space optical communication, including quantum communication

    Science.gov (United States)

    Nordholt, Jane Elizabeth; Newell, Raymond Thorson; Peterson, Charles Glen; Hughes, Richard John

    2018-01-09

    Quantum communication transmitters include beacon lasers that transmit a beacon optical signal in a predetermined state of polarization such as one of the states of polarization of a quantum communication basis. Changes in the beacon polarization are detected at a receiver, and a retarder is adjusted so that the states of polarization in a received quantum communication optical signal are matched to basis polarizations. The beacon and QC signals can be at different wavelengths so that the beacon does not interfere with detection and decoding of the QC optical signal.

  16. Multifractal characteristics of optical turbulence measured through a single beam holographic process.

    Science.gov (United States)

    Pérez, Darío G; Barillé, Regis; Morille, Yohann; Zielińska, Sonia; Ortyl, Ewelina

    2014-08-11

    We have previously shown that azopolymer thin films exposed to coherent light that has travelled through a turbulent medium produces a surface relief grating containing information about the intensity of the turbulence; for instance, a relation between the refractive index structure constant C(n)2 as a function of the surface parameters was obtained. In this work, we show that these films capture much more information about the turbulence dynamics. Multifractal detrended fluctuation and fractal dimension analysis from images of the surface roughness produced by the light on the azopolymer reveals scaling properties related to those of the optical turbulence.

  17. Performance of wireless optical communication systems under polarization effects over atmospheric turbulence

    Science.gov (United States)

    Zhang, Jiankun; Li, Ziyang; Dang, Anhong

    2018-06-01

    It has been recntly shown that polarization state of propagation beam would suffer from polarization fluctuations due to the detrimental effects of atmospheric turbulence. This paper studies the performance of wireless optical communication (WOC) systems in the presence of polarization effect of atmosphere. We categorize the atmospheric polarization effect into polarization rotation, polarization-dependent power loss, and phase shift effect, with each effect described and modeled with the help of polarization-coherence theory and the extended Huygens-Fresnelprinciple. The channel matrices are derived to measure the cross-polarization interference of the system. Signal-to-noise ratio and bit error rate for polarization multiplexing system and polarization modulation system are obtained to assess the viability using the approach of M turbulence model. Monte Carlo simulation results show the performance of polarization based WOC systems to be degraded by atmospheric polarization effect, which could be evaluated precisely using the proposed model with given turbulent strengths.

  18. Polarization variablity among Wolf-Rayet stars. IV. A complete lack of circular polarization in the optical continuum

    International Nuclear Information System (INIS)

    Robert, C.; Moffat, A.F.J.

    1989-01-01

    Quasi-simultaneous blue and red, broadband optical monitoring in linear and circular polarization and in intensity has been carried out over an interval of three weeks for several Wolf-Rayet stars that show relatively large Delta P variations in linear polarization. No significant varying Delta V component of circular polarization is detected in any of these stars. The lower upper limit Delta V/Delta P implies that the intrinsic linearly polarized light which does vary cannot be produced by electrons gyrating in a magnetic field, unless they are ultrarelativistic - a rather unlikely situation. The low mean circular polarization typically observed is probably interstellar in origin. Lack of periodicity in the observed variations of linear polarization implies that even weak magnetic field loops are unlikely to be involved in confining pockets of wind plasma. The observed linear polarization variations are related mainly to electron scattering. 25 refs

  19. OPTICAL POLARIZATION AND SPECTRAL VARIABILITY IN THE M87 JET

    Energy Technology Data Exchange (ETDEWEB)

    Perlman, Eric S.; Cara, Mihai; Bourque, Matthew; Simons, Raymond C. [Department of Physics and Space Sciences, 150 W. University Blvd., Florida Institute of Technology, Melbourne, FL 32901 (United States); Adams, Steven C. [Department of Physics and Astronomy, University of Georgia, Athens, GA 30605 (United States); Harris, D. E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Madrid, Juan P. [Center for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122 (Australia); Clausen-Brown, Eric [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Cheung, C. C. [National Academy of Sciences, Washington, DC 20001 (United States); Stawarz, Lukasz [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Georganopoulos, Markos [Department of Physics, University of Maryland-Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Sparks, William B.; Biretta, John A., E-mail: eperlman@fit.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2011-12-20

    During the last decade, M87's jet has been the site of an extraordinary variability event, with one knot (HST-1) increasing by over a factor 100 in brightness. Variability has also been seen on timescales of months in the nuclear flux. Here we discuss the optical-UV polarization and spectral variability of these components, which show vastly different behavior. HST-1 shows a highly significant correlation between flux and polarization, with P increasing from {approx}20% at minimum to >40% at maximum, while the orientation of its electric vector stayed constant. HST-1's optical-UV spectrum is very hard ({alpha}{sub UV-O} {approx} 0.5, F{sub {nu}}{proportional_to}{nu}{sup -{alpha}}), and displays 'hard lags' during epochs 2004.9-2005.5, including the peak of the flare, with soft lags at later epochs. We interpret the behavior of HST-1 as enhanced particle acceleration in a shock, with cooling from both particle aging and the relaxation of the compression. We set 2{sigma} upper limits of 0.5{delta} pc and 1.02c on the size and advance speed of the flaring region. The slight deviation of the electric vector orientation from the jet position angle (P.A.) makes it likely that on smaller scales the flaring region has either a double or twisted structure. By contrast, the nucleus displays much more rapid variability, with a highly variable electric vector orientation and 'looping' in the (I, P) plane. The nucleus has a much steeper spectrum ({alpha}{sub UV-O} {approx} 1.5) but does not show UV-optical spectral variability. Its behavior can be interpreted as either a helical distortion to a steady jet or a shock propagating through a helical jet.

  20. OPTICAL POLARIZATION AND SPECTRAL VARIABILITY IN THE M87 JET

    International Nuclear Information System (INIS)

    Perlman, Eric S.; Cara, Mihai; Bourque, Matthew; Simons, Raymond C.; Adams, Steven C.; Harris, D. E.; Madrid, Juan P.; Clausen-Brown, Eric; Cheung, C. C.; Stawarz, Lukasz; Georganopoulos, Markos; Sparks, William B.; Biretta, John A.

    2011-01-01

    During the last decade, M87's jet has been the site of an extraordinary variability event, with one knot (HST-1) increasing by over a factor 100 in brightness. Variability has also been seen on timescales of months in the nuclear flux. Here we discuss the optical-UV polarization and spectral variability of these components, which show vastly different behavior. HST-1 shows a highly significant correlation between flux and polarization, with P increasing from ∼20% at minimum to >40% at maximum, while the orientation of its electric vector stayed constant. HST-1's optical-UV spectrum is very hard (α UV-O ∼ 0.5, F ν ∝ν –α ), and displays 'hard lags' during epochs 2004.9-2005.5, including the peak of the flare, with soft lags at later epochs. We interpret the behavior of HST-1 as enhanced particle acceleration in a shock, with cooling from both particle aging and the relaxation of the compression. We set 2σ upper limits of 0.5δ pc and 1.02c on the size and advance speed of the flaring region. The slight deviation of the electric vector orientation from the jet position angle (P.A.) makes it likely that on smaller scales the flaring region has either a double or twisted structure. By contrast, the nucleus displays much more rapid variability, with a highly variable electric vector orientation and 'looping' in the (I, P) plane. The nucleus has a much steeper spectrum (α UV-O ∼ 1.5) but does not show UV-optical spectral variability. Its behavior can be interpreted as either a helical distortion to a steady jet or a shock propagating through a helical jet.

  1. Optic axis determination by fibre-based polarization-sensitive swept-source optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lu Zenghai; Kasaragod, Deepa K; Matcher, Stephen J, E-mail: z.lu@sheffield.ac.uk, E-mail: s.j.matcher@sheffield.ac.uk [Department of Materials Science and Engineering, Kroto Research Institute, University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ (United Kingdom)

    2011-02-21

    We describe a fibre-based variable-incidence angle (VIA) polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) system to determine the 3D optical axis of birefringent biological tissues. Single-plane VIA-PS-OCT is also explored which requires measurement of the absolute fast-axis orientation. A state-of-the-art PS-SS-OCT system with some improvements both in hardware and software was used to determine the apparent optical birefringence of equine tendon for a number of different illumination directions. Polar and azimuthal angles of cut equine tendon were produced by the VIA method and compared with the nominal values. A quarter waveplate (QWP) and equine tendon were used as test targets to validate the fast-axis measurements using the system. Polar and azimuthal angles of cut equine tendon broadly agreed with the expected values within about 8% of the nominal values. A theoretical and experimental analysis of the effect of the sample arm fibre on determination of optical axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for special settings of the sample arm fibre. A proposed algorithm based on the angle between Stokes vectors on the Poincare sphere is confirmed to work for all settings of the sample arm fibre. A calibration procedure is proposed to remove the sign ambiguity of the measured orientation and was confirmed experimentally by using the QWP.

  2. Optic axis determination by fibre-based polarization-sensitive swept-source optical coherence tomography

    International Nuclear Information System (INIS)

    Lu Zenghai; Kasaragod, Deepa K; Matcher, Stephen J

    2011-01-01

    We describe a fibre-based variable-incidence angle (VIA) polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) system to determine the 3D optical axis of birefringent biological tissues. Single-plane VIA-PS-OCT is also explored which requires measurement of the absolute fast-axis orientation. A state-of-the-art PS-SS-OCT system with some improvements both in hardware and software was used to determine the apparent optical birefringence of equine tendon for a number of different illumination directions. Polar and azimuthal angles of cut equine tendon were produced by the VIA method and compared with the nominal values. A quarter waveplate (QWP) and equine tendon were used as test targets to validate the fast-axis measurements using the system. Polar and azimuthal angles of cut equine tendon broadly agreed with the expected values within about 8% of the nominal values. A theoretical and experimental analysis of the effect of the sample arm fibre on determination of optical axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for special settings of the sample arm fibre. A proposed algorithm based on the angle between Stokes vectors on the Poincare sphere is confirmed to work for all settings of the sample arm fibre. A calibration procedure is proposed to remove the sign ambiguity of the measured orientation and was confirmed experimentally by using the QWP.

  3. Comparison of Gini index and Tamura coefficient for holographic autofocusing based on the edge sparsity of the complex optical wavefront

    KAUST Repository

    Tamamitsu, Miu; Zhang, Yibo; Wang, Hongda; Wu, Yichen; Ozcan, Aydogan

    2017-01-01

    of sparsity metrics used in SoG, specifically, the Gini index (GI) and the Tamura coefficient (TC), for holographic autofocusing on dense/connected or sparse samples. We provide a theoretical analysis predicting that for uniformly distributed image data, TC

  4. Massive parallel optical pattern recognition and retrieval via a two-stage high-capacity multichannel holographic random access memory system

    International Nuclear Information System (INIS)

    Cai, Luzhong; Liu, Hua-Kuang

    2000-01-01

    The multistage holographic optical random access memory (HORAM) system reported recently by Liu et al. provides a new degree of freedom for improving storage capacity. We further present a theoretical and practical analysis of the HORAM system with experimental results. Our discussions include the system design and geometrical requirements, its applications for multichannel pattern recognition and associative memory, the 2-D and 3-D information storage capacity, and multichannel image storage and retrieval via VanderLugt correlator (VLC) filters and joint transform holograms. A series of experiments are performed to demonstrate the feasibility of the multichannel pattern recognition and image retrieval with both the VLC and joint transform correlator (JTC) architectures. The experimental results with as many as 2025 channels show good agreement with the theoretical analysis. (c) 2000 Society of Photo-Optical Instrumentation Engineers

  5. Optically induced rotation of Rayleigh particles by vortex beams with different states of polarization

    International Nuclear Information System (INIS)

    Li, Manman; Yan, Shaohui; Yao, Baoli; Liang, Yansheng; Lei, Ming; Yang, Yanlong

    2016-01-01

    Optical vortex beams carry optical orbital angular momentum (OAM) and can induce an orbital motion of trapped particles in optical trapping. We show that the state of polarization (SOP) of vortex beams will affect the details of this optically induced orbital motion to some extent. Numerical results demonstrate that focusing the vortex beams with circular, radial or azimuthal polarizations can induce a uniform orbital motion on a trapped Rayleigh particle, while in the focal field of the vortex beam with linear polarization the particle experiences a non-uniform orbital motion. Among the formers, the vortex beam with circular polarization induces a maximum optical torque on the particle. Furthermore, by varying the topological charge of the vortex beams, the vortex beam with circular polarization gives rise to an optimum torque superior to those given by the other three vortex beams. These facts suggest that the circularly polarized vortex beam is more suitable for rotating particles. - Highlights: • States of polarization of vortex beams affect the optically induced orbital motion of particles. • The dependences of the force and orbital torque on the topological charge, the size and the absorptivity of particles were calculated. • Focused vortex beams with circular, radial or azimuthal polarizations induce a uniform orbital motion on particles. • Particles experience a non-uniform orbital motion in the focused linearly polarized vortex beam. • The circularly polarized vortex beam is a superior candidate for rotating particles.

  6. Optical Field-Strength Polarization of Two-Mode Single-Photon States

    Science.gov (United States)

    Linares, J.; Nistal, M. C.; Barral, D.; Moreno, V.

    2010-01-01

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of…

  7. Optical polarization based logic functions (XOR or XNOR) with nonlinear Gallium nitride nanoslab.

    Science.gov (United States)

    Bovino, F A; Larciprete, M C; Giardina, M; Belardini, A; Centini, M; Sibilia, C; Bertolotti, M; Passaseo, A; Tasco, V

    2009-10-26

    We present a scheme of XOR/XNOR logic gate, based on non phase-matched noncollinear second harmonic generation from a medium of suitable crystalline symmetry, Gallium nitride. The polarization of the noncollinear generated beam is a function of the polarization of both pump beams, thus we experimentally investigated all possible polarization combinations, evidencing that only some of them are allowed and that the nonlinear interaction of optical signals behaves as a polarization based XOR. The experimental results show the peculiarity of the nonlinear optical response associated with noncollinear excitation, and are explained using the expression for the effective second order optical nonlinearity in noncollinear scheme.

  8. Optical parametric amplification of arbitrarily polarized light in periodically poled LiNbO3.

    Science.gov (United States)

    Shao, Guang-hao; Song, Xiao-shi; Xu, Fei; Lu, Yan-qing

    2012-08-13

    Optical parametric amplification (OPA) of arbitrarily polarized light is proposed in a multi-section periodically poled Lithium Niobate (PPLN). External electric field is applied on selected sections to induce the polarization rotation of involved lights, thus the quasi-phase matched optical parametric processes exhibit polarization insensitivity under suitable voltage. In addition to the amplified signal wave, an idler wave with the same polarization is generated simultaneously. As an example, a ~10 times OPA showing polarization independency is simulated. Applications of this technology are also discussed.

  9. Production of polarized negative deuterium ion beam with dual optical pumping in KEK

    Energy Technology Data Exchange (ETDEWEB)

    Kinsho, M.; Ikegami, K.; Takagi, A. [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan); Mori, Y.

    1997-02-01

    To obtain highly nuclear-spin vector polarized negative deuterium ion beam, a dual optically pumped polarized negative deuterium ion source has been developed at KEK. It is possible to select a pure nuclear-spin state with this scheme, and negative deuterium ion beam with 100% nuclear-spin vector polarization can be produced in principle. We have obtained about 70% of nuclear-spin vector polarized negative deuterium ion beam so far. This result may open up a new possibilities for the optically pumped polarized ion source. (author)

  10. Great circle solution to polarization-based quantum communication (QC) in optical fiber

    Science.gov (United States)

    Nordholt, Jane Elizabeth; Peterson, Charles Glen; Newell, Raymond Thorson; Hughes, Richard John

    2016-03-15

    Birefringence in optical fibers is compensated by applying polarization modulation at a receiver. Polarization modulation is applied so that a transmitted optical signal has states of polarization (SOPs) that are equally spaced on the Poincare sphere. Fiber birefringence encountered in propagation between a transmitter and a receiver rotates the great circle on the Poincare sphere that represents the polarization bases used for modulation. By adjusting received polarizations, polarization components of the received optical signal can be directed to corresponding detectors for decoding, regardless of the magnitude and orientation of the fiber birefringence. A transmitter can be configured to transmit in conjugate polarization bases whose SOPs can be represented as equidistant points on a great circle so that the received SOPs are mapped to equidistant points on a great circle and routed to corresponding detectors.

  11. FDTD simulations of forces on particles during holographic assembly.

    Science.gov (United States)

    Benito, David C; Simpson, Stephen H; Hanna, Simon

    2008-03-03

    We present finite-difference time-domain (FDTD) calculations of the forces and torques on dielectric particles of various shapes, held in one or many Gaussian optical traps, as part of a study of the physical limitations involved in the construction of micro- and nanostructures using a dynamic holographic assembler (DHA). We employ a full 3-dimensional FDTD implementation, which includes a complete treatment of optical anisotropy. The Gaussian beams are sourced using a multipole expansion of a fifth order Davis beam. Force and torques are calculated for pairs of silica spheres in adjacent traps, for silica cylinders trapped by multiple beams and for oblate silica spheroids and calcite spheres in both linearly and circularly polarized beams. Comparisons are drawn between the magnitudes of the optical forces and the Van der Waals forces acting on the systems. The paper also considers the limitations of the FDTD approach when applied to optical trapping.

  12. Deuteron transverse densities in holographic QCD

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Chandan [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Indian Institute of Technology Kanpur, Department of Physics, Kanpur (India); Chakrabarti, Dipankar [Indian Institute of Technology Kanpur, Department of Physics, Kanpur (India); Zhao, Xingbo [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China)

    2017-05-15

    We investigate the transverse charge density in the longitudinally as well as transversely polarized deuteron using the recent empirical description of the deuteron electromagnetic form factors in the framework of holographic QCD. The predictions of the holographic QCD are compared with the results of a standard phenomenological parameterization. In addition, we evaluate GPDs and the gravitational form factors for the deuteron. The longitudinal momentum densities are also investigated in the transverse plane. (orig.)

  13. Side-chain liquid crystalline polyesters for optical information storage

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Holme, Christian; Hvilsted, Søren

    1996-01-01

    and holographic storage in one particular polyester are described in detail and polarized Fourier transform infrared spectroscopic data complementing the optical data are presented. Optical and atomic force microscope investigations point to a laser-induced aggregation as responsible for permanent optical storage.......Azobenzene side-chain liquid crystalline polyester structures suitable for permanent optical storage are described. The synthesis and characterization of the polyesters together with differential scanning calorimetry and X-ray investigations are discussed. Optical anisotropic investigations...

  14. Engaging Montana high school students in optical sciences with a polarization photo contest

    Science.gov (United States)

    Tauc, Martin Jan; Boger, James K.; Hohne, Andrew; Dahl, Laura M.; Nugent, Paul W.; Riesland, David W.; Moon, Benjamin; Baumbauer, Carol L.; Boese, Orrin; Shaw, Joseph A.; Nakagawa, Wataru

    2017-08-01

    Getting students interested in science, specifically in optics and photonics, is a worthwhile challenge. We developed and implemented an outreach campaign that sought to engage high school students in the science of polarized light. We traveled to Montana high schools and presented on the physics of light, the ways that it becomes polarized, how polarization is useful, and how to take pictures with linear polarizers to see polarization. Students took pictures that showed polarization in either a natural setting or a contrived scene. We visited 13 high schools, and presented live to approximately 450 students.

  15. Centralized light-source optical access network based on polarization multiplexing.

    Science.gov (United States)

    Grassi, Fulvio; Mora, José; Ortega, Beatriz; Capmany, José

    2010-03-01

    This paper presents and demonstrates a centralized light source optical access network based on optical polarization multiplexing technique. By using two optical sources emitting light orthogonally polarized in the Central Node for downstream and upstream operations, the Remote Node is kept source-free. EVM values below telecommunication standard requirements have been measured experimentally when bidirectional digital signals have been transmitted over 10 km of SMF employing subcarrier multiplexing technique in the electrical domain.

  16. Laser adaptive holographic hydrophone

    Energy Technology Data Exchange (ETDEWEB)

    Romashko, R V; Kulchin, Yu N; Bezruk, M N; Ermolaev, S A [Institute of Automation and Control Processes, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok (Russian Federation)

    2016-03-31

    A new type of a laser hydrophone based on dynamic holograms, formed in a photorefractive crystal, is proposed and studied. It is shown that the use of dynamic holograms makes it unnecessary to use complex optical schemes and systems for electronic stabilisation of the interferometer operating point. This essentially simplifies the scheme of the laser hydrophone preserving its high sensitivity, which offers the possibility to use it under a strong variation of the environment parameters. The laser adaptive holographic hydrophone implemented at present possesses the sensitivity at a level of 3.3 mV Pa{sup -1} in the frequency range from 1 to 30 kHz. (laser hydrophones)

  17. Volume holographic memory

    Directory of Open Access Journals (Sweden)

    Cornelia Denz

    2000-05-01

    Full Text Available Volume holography represents a promising alternative to existing storage technologies. Its parallel data storage leads to high capacities combined with short access times and high transfer rates. The design and realization of a compact volume holographic storage demonstrator is presented. The technique of phase-coded multiplexing implemented to superimpose many data pages in a single location enables to store up to 480 holograms per storage location without any moving parts. Results of analog and digital data storage are shown and real time optical image processing is demonstrated.

  18. Robust holographic storage system design.

    Science.gov (United States)

    Watanabe, Takahiro; Watanabe, Minoru

    2011-11-21

    Demand is increasing daily for large data storage systems that are useful for applications in spacecraft, space satellites, and space robots, which are all exposed to radiation-rich space environment. As candidates for use in space embedded systems, holographic storage systems are promising because they can easily provided the demanded large-storage capability. Particularly, holographic storage systems, which have no rotation mechanism, are demanded because they are virtually maintenance-free. Although a holographic memory itself is an extremely robust device even in a space radiation environment, its associated lasers and drive circuit devices are vulnerable. Such vulnerabilities sometimes engendered severe problems that prevent reading of all contents of the holographic memory, which is a turn-off failure mode of a laser array. This paper therefore presents a proposal for a recovery method for the turn-off failure mode of a laser array on a holographic storage system, and describes results of an experimental demonstration. © 2011 Optical Society of America

  19. Polarization-insensitive quantum-dot coupled quantum-well semiconductor optical amplifier

    International Nuclear Information System (INIS)

    Huang Lirong; Yu Yi; Tian Peng; Huang Dexiu

    2009-01-01

    The optical gain of a quantum-dot semiconductor optical amplifier is usually seriously dependent on polarization; we propose a quantum-dot coupled tensile-strained quantum-well structure to obtain polarization insensitivity. The tensile-strained quantum well not only serves as a carrier injection layer of quantum dots but also offers gain to the transverse-magnetic mode. Based on the polarization-dependent coupled carrier rate-equation model, we study carrier competition among quantum well and quantum dots, and study the polarization dependence of the quantum-dot coupled quantum-well semiconductor optical amplifier. We also analyze polarization-dependent photon-mediated carrier distribution among quantum well and quantum dots. It is shown that polarization-insensitive gain can be realized by optimal design

  20. Optical-wireless-optical full link for polarization multiplexing quadrature amplitude/phase modulation signal transmission.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Chi, Nan; Zhang, Junwen

    2013-11-15

    We propose and experimentally demonstrate an optical wireless integration system at the Q-band, in which up to 40 Gb/s polarization multiplexing multilevel quadrature amplitude/phase modulation (PM-QAM) signal can be first transmitted over 20 km single-mode fiber-28 (SMF-28), then delivered over a 2 m 2 × 2 multiple-input multiple-output wireless link, and finally transmitted over another 20 km SMF-28. The PM-QAM modulated wireless millimeter-wave (mm-wave) signal at 40 GHz is generated based on the remote heterodyning technique, and demodulated by the radio-frequency transparent photonic technique based on homodyne coherent detection and baseband digital signal processing. The classic constant modulus algorithm equalization is used at the receiver to realize polarization demultiplexing of the PM-QAM signal. For the first time, to the best of our knowledge, we realize the conversion of the PM-QAM modulated wireless mm-wave signal to the optical signal as well as 20 km fiber transmission of the converted optical signal.

  1. Extreme-Scale Alignments Of Quasar Optical Polarizations And Galactic Dust Contamination

    Science.gov (United States)

    Pelgrims, Vincent

    2017-10-01

    Almost twenty years ago the optical polarization vectors from quasars were shown to be aligned over extreme-scales. That evidence was later confirmed and enhanced thanks to additional optical data obtained with the ESO instrument FORS2 mounted on the VLT, in Chile. These observations suggest either Galactic foreground contamination of the data or, more interestingly, a cosmological origin. Using 353-GHz polarization data from the Planck satellite, I recently showed that the main features of the extreme-scale alignments of the quasar optical polarization vectors are unaffected by the Galactic thermal dust. This confirms previous studies based on optical starlight polarization and discards the scenario of Galactic contamination. In this talk, I shall briefly review the extreme-scale quasar polarization alignments, discuss the main results submitted in A&A and motivate forthcoming projects at the frontier between Galactic and extragalactic astrop hysics.

  2. Holographic Phonons

    Science.gov (United States)

    Alberte, Lasma; Ammon, Martin; Jiménez-Alba, Amadeo; Baggioli, Matteo; Pujolàs, Oriol

    2018-04-01

    We present a class of holographic massive gravity models that realize a spontaneous breaking of translational symmetry—they exhibit transverse phonon modes whose speed relates to the elastic shear modulus according to elasticity theory. Massive gravity theories thus emerge as versatile and convenient theories to model generic types of translational symmetry breaking: explicit, spontaneous, and a mixture of both. The nature of the breaking is encoded in the radial dependence of the graviton mass. As an application of the model, we compute the temperature dependence of the shear modulus and find that it features a glasslike melting transition.

  3. Mass production of volume holographic optical elements (vHOEs) using Bayfol® HX photopolymer film in a roll-to-roll copy process

    Science.gov (United States)

    Bruder, Friedrich-Karl; Fäcke, Thomas; Grote, Fabian; Hagen, Rainer; Hönel, Dennis; Koch, Eberhard; Rewitz, Christian; Walze, Günther; Wewer, Brita

    2017-03-01

    Volume Holographic Optical Elements (vHOEs) gained wide attention as optical combiners for the use in augmented and virtual reality (AR and VR, respectively) consumer electronics and automotive head-up display applications. The unique characteristics of these diffractive grating structures - being lightweight, thin and flat - make them perfectly suitable for use in integrated optical components like spectacle lenses and car windshields. While being transparent in Off-Bragg condition, they provide full color capability and adjustable diffraction efficiency. The instant developing photopolymer Bayfol® HX film provides an ideal technology platform to optimize the performance of vHOEs in a wide range of applications. Important for any commercialization are simple and robust mass production schemes. In this paper, we present an efficient and easy to control one-beam recording scheme to copy a so-called master vHOE in a step-and-repeat process. In this contact-copy scheme, Bayfol® HX film is laminated to a master stack before being exposed by a scanning laser line. Subsequently, the film is delaminated in a controlled fashion and bleached. We explain working principles of the one-beam copy concept and discuss the mechanical construction of the installed vHOE replication line. Moreover, we treat aspects like master design, effects of vibration and suppression of noise gratings. Furthermore, digital vHOEs are introduced as master holograms. They enable new ways of optical design and paths to large scale vHOEs.

  4. PolarTrack: Optical Outside-In Device Tracking that Exploits Display Polarization

    DEFF Research Database (Denmark)

    Rädle, Roman; Jetter, Hans-Christian; Fischer, Jonathan

    2018-01-01

    PolarTrack is a novel camera-based approach to detecting and tracking mobile devices inside the capture volume. In PolarTrack, a polarization filter continuously rotates in front of an off-the-shelf color camera, which causes the displays of observed devices to periodically blink in the camera feed....... The periodic blinking results from the physical characteristics of current displays, which shine polarized light either through an LC overlay to produce images or through a polarizer to reduce light reflections on OLED displays. PolarTrack runs a simple detection algorithm on the camera feed to segment...... displays and track their locations and orientations, which makes PolarTrack particularly suitable as a tracking system for cross-device interaction with mobile devices. Our evaluation of PolarTrack's tracking quality and comparison with state-of-the-art camera-based multi-device tracking showed a better...

  5. Holographic Aquaculture

    Science.gov (United States)

    Ian, Richard; King, Elisabeth

    1988-01-01

    Proposed is an exploratory study to verify the feasibility of an inexpensive micro-climate control system for both marine and freshwater pond and tank aquaculture, offering good control over water temperature, incident light flux, and bandwidth, combined with good energy efficiency. The proposed control system utilizes some familiar components of passive solar design, together with a new holographic glazing system which is currently being developed by, and proprietary to Advanced Environmental Research Group (AERG). The use of solar algae ponds and tanks to warm and purify water for fish and attached macroscopic marine algae culture is an ancient and effective technique, but limited seasonally and geographically by the availability of sunlight. Holographic Diffracting Structures (HDSs) can be made which passively track, accept and/or reject sunlight from a wide range of altitude and azimuth angles, and redirect and distribute light energy as desired (either directly or indirectly over water surface in an enclosed, insulated structure), effectively increasing insolation values by accepting sunlight which would not otherwise enter the structure.

  6. Effects of polarization and absorption on laser induced optical breakdown threshold for skin rejuvenation

    Science.gov (United States)

    Varghese, Babu; Bonito, Valentina; Turco, Simona; Verhagen, Rieko

    2016-03-01

    Laser induced optical breakdown (LIOB) is a non-linear absorption process leading to plasma formation at locations where the threshold irradiance for breakdown is surpassed. In this paper we experimentally demonstrate the influence of polarization and absorption on laser induced breakdown threshold in transparent, absorbing and scattering phantoms made from water suspensions of polystyrene microspheres. We demonstrate that radially polarized light yields a lower irradiance threshold for creating optical breakdown compared to linearly polarized light. We also demonstrate that the thermal initiation pathway used for generating seed electrons results in a lower irradiance threshold compared to multiphoton initiation pathway used for optical breakdown.

  7. Polarization control of non-diffractive helical optical beams through subwavelength metallic apertures

    International Nuclear Information System (INIS)

    Lombard, E; Genet, C; Ebbesen, T W; Drezet, A

    2010-01-01

    We demonstrate experimentally a simple method for preparing non-diffractive vectorial optical beams that can display wave-front helicity. This method is based on space-variant modifications of the polarization of an optical beam transmitted through subwavelength annular rings perforating opaque metal films. We show how the description of the optical properties of such structures must account for the vectorial character of the polarization and how, in turn, these properties can be controlled by straightforward sequences of preparation and analysis of polarization states.

  8. Environmental performance of an elliptical core polarization maintaining optical fiber for fiber optic gyro applications

    Science.gov (United States)

    Martinelli, Vincent P.; Squires, Emily M.; Watkins, James J.

    1994-03-01

    Corning has introduced a new polarization-maintaining optical fiber to satisfy customer requirements for a range of commercial and military FOG applications. This fiber has an elliptical core, matched-clad design, and is intended for operation in the 780 to 850 nm wavelength region. The fiber has a beat length less than 1.5 mm, attenuation rate less than 10 dB/km, and a typical coiled h-parameter less than 1.5 X 10-4 m-1 in the designated operating wavelength range. It has a cladding diameter of 80 micrometers and a coating diameter of 185 micrometers . The coating is an acrylate system, similar to that used in telecommunications optical fibers. We report on the performance of this elliptical core fiber for a variety of environmental exposures representative of an automotive application.

  9. Biophotopol: A Sustainable Photopolymer for Holographic Data Storage Applications

    Directory of Open Access Journals (Sweden)

    Augusto Beléndez

    2012-05-01

    Full Text Available Photopolymers have proved to be useful for different holographic applications such as holographic data storage or holographic optical elements. However, most photopolymers have certain undesirable features, such as the toxicity of some of their components or their low environmental compatibility. For this reason, the Holography and Optical Processing Group at the University of Alicante developed a new dry photopolymer with low toxicity and high thickness called biophotopol, which is very adequate for holographic data storage applications. In this paper we describe our recent studies on biophotopol and the main characteristics of this material.

  10. The compact and inexpensive arrowhead setup for holographic interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Ladera, Celso L; Donoso, Guillermo, E-mail: clladera@usb.v [Departamento de Fisica, Universidad Simon BolIvar, Apdo. 89000, Caracas 1086 (Venezuela, Bolivarian Republic of)

    2011-07-15

    Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that requires neither a collimator nor a beam-splitter, and whose layout is reminiscent of an arrowhead. We show that this inexpensive setup is a good alternative for the study and applications of scientific holography by measuring small displacements and deformations of a body. The arrowhead setup will be found particularly useful for holography and holographic interferometry experiments and projects in teaching laboratories.

  11. Doubling transmission capacity in optical wireless system by antenna horizontal- and vertical-polarization multiplexing.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Zhang, Junwen; Dong, Ze; Chi, Nan

    2013-06-15

    We experimentally demonstrate 2×56 Gb/s two-channel polarization-division-multiplexing quadrature-phase-shift-keying signal delivery over 80 km single-mode fiber-28 and 2 m Q-band (33-50 GHz) wireless link, adopting antenna horizontal- (H-) and vertical-polarization (V-polarization) multiplexing. At the wireless receiver, classic constant-modulus-algorithm equalization based on digital signal processing can realize polarization demultiplexing and remove the crosstalk at the same antenna polarization. By adopting antenna polarization multiplexing, the signal baud rate and performance requirements for optical and wireless devices can be reduced but at the cost of double antennas and devices, while wireless transmission capacity can also be increased but at the cost of stricter requirements for V-polarization. The isolation is only about 19 dB when V-polarization deviation approaches 10°, which will affect high-speed (>50 Gb/s) wireless delivery.

  12. Three-dimensional orientation-unlimited polarization encryption by a single optically configured vectorial beam.

    Science.gov (United States)

    Li, Xiangping; Lan, Tzu-Hsiang; Tien, Chung-Hao; Gu, Min

    2012-01-01

    The interplay between light polarization and matter is the basis of many fundamental physical processes and applications. However, the electromagnetic wave nature of light in free space sets a fundamental limit on the three-dimensional polarization orientation of a light beam. Although a high numerical aperture objective can be used to bend the wavefront of a radially polarized beam to generate the longitudinal polarization state in the focal volume, the arbitrary three-dimensional polarization orientation of a beam has not been achieved yet. Here we present a novel technique for generating arbitrary three-dimensional polarization orientation by a single optically configured vectorial beam. As a consequence, by applying this technique to gold nanorods, orientation-unlimited polarization encryption with ultra-security is demonstrated. These results represent a new landmark of the orientation-unlimited three-dimensional polarization control of the light-matter interaction.

  13. Fast, High-Precision Optical Polarization Synthesizer for Ultracold-Atom Experiments

    Science.gov (United States)

    Robens, Carsten; Brakhane, Stefan; Alt, Wolfgang; Meschede, Dieter; Zopes, Jonathan; Alberti, Andrea

    2018-03-01

    We present a technique for the precision synthesis of arbitrary polarization states of light with a high modulation bandwidth. Our approach consists of superimposing two laser light fields with the same wavelength, but with opposite circular polarizations, where the phase and the amplitude of each light field are individually controlled. We find that the polarization-synthesized beam reaches a degree of polarization of 99.99%, which is mainly limited by static spatial variations of the polarization state over the beam profile. We also find that the depolarization caused by temporal fluctuations of the polarization state is about 2 orders of magnitude smaller. In a recent work, Robens et al. [Low-Entropy States of Neutral Atoms in Polarization-Synthesized Optical Lattices, Phys. Rev. Lett. 118, 065302 (2017), 10.1103/PhysRevLett.118.065302] demonstrated an application of the polarization synthesizer to create two independently controllable optical lattices which trap atoms depending on their internal spin state. We use ultracold atoms in polarization-synthesized optical lattices to give an independent, in situ demonstration of the performance of the polarization synthesizer.

  14. Metastability-exchange optical pumping of 3He for neutron polarizers

    International Nuclear Information System (INIS)

    Gentile, T.R.; Thompson, A.K.; Snow, W.M.

    1995-01-01

    Research is underway at NIST and IU to develop neutron polarizers that are based on polarized 3 He. Such polarizers rely on the strong spin dependence of the cross section for neutron capture by polarized 3 He. Two methods can produce the high density of polarized 3 He gas (10 19 -10 20 cm -3 ) required for an effective neutron polarizer: spin-exchange optical pumping, which is performed directly at high pressure (1-10 bar), and metastability-exchange optical pumping, in which the gas is polarized at low pressure (1 mbar) and then compressed. While we are pursuing both methods, progress in the metastable method will be discussed. The features of the metastable method are the high rate at which the gas can be polarized and the inherent separation of the optical pumping and target cells. In a landmark achievement, researchers at the Univ. of Mainz have developed a piston compressor that can fill a 130 cm 3 cell to a pressure of 7 bar of 45% polarized 3 He gas in 2 hours. We plan to develop a compressor and test it at the NIST Cold Neutron Research Facility. We have constructed a metastable-pumping apparatus at NIST and have obtained 76% polarization with a pumping rate of 1.2 x 10 18 atoms/sec in a 0.4 mbar, 270 cm 3 cell

  15. Comparison of Gini index and Tamura coefficient for holographic autofocusing based on the edge sparsity of the complex optical wavefront

    KAUST Repository

    Tamamitsu, Miu

    2017-08-27

    The Sparsity of the Gradient (SoG) is a robust autofocusing criterion for holography, where the gradient modulus of the complex refocused hologram is calculated, on which a sparsity metric is applied. Here, we compare two different choices of sparsity metrics used in SoG, specifically, the Gini index (GI) and the Tamura coefficient (TC), for holographic autofocusing on dense/connected or sparse samples. We provide a theoretical analysis predicting that for uniformly distributed image data, TC and GI exhibit similar behavior, while for naturally sparse images containing few high-valued signal entries and many low-valued noisy background pixels, TC is more sensitive to distribution changes in the signal and more resistive to background noise. These predictions are also confirmed by experimental results using SoG-based holographic autofocusing on dense and connected samples (such as stained breast tissue sections) as well as highly sparse samples (such as isolated Giardia lamblia cysts). Through these experiments, we found that ToG and GoG offer almost identical autofocusing performance on dense and connected samples, whereas for naturally sparse samples, GoG should be calculated on a relatively small region of interest (ROI) closely surrounding the object, while ToG offers more flexibility in choosing a larger ROI containing more background pixels.

  16. Estimates of Leaf Relative Water Content from Optical Polarization Measurements

    Science.gov (United States)

    Dahlgren, R. P.; Vanderbilt, V. C.; Daughtry, C. S. T.

    2017-12-01

    Remotely sensing the water status of plant canopies remains a long term goal of remote sensing research. Existing approaches to remotely sensing canopy water status, such as the Crop Water Stress Index (CWSI) and the Equivalent Water Thickness (EWT), have limitations. The CWSI, based upon remotely sensing canopy radiant temperature in the thermal infrared spectral region, does not work well in humid regions, requires estimates of the vapor pressure deficit near the canopy during the remote sensing over-flight and, once stomata close, provides little information regarding the canopy water status. The EWT is based upon the physics of water-light interaction in the 900-2000nm spectral region, not plant physiology. Our goal, development of a remote sensing technique for estimating plant water status based upon measurements in the VIS/NIR spectral region, would potentially provide remote sensing access to plant dehydration physiology - to the cellular photochemistry and structural changes associated with water deficits in leaves. In this research, we used optical, crossed polarization filters to measure the VIS/NIR light reflected from the leaf interior, R, as well as the leaf transmittance, T, for 78 corn (Zea mays) and soybean (Glycine max) leaves having relative water contents (RWC) between 0.60 and 0.98. Our results show that as RWC decreases R increases while T decreases. Our results tie R and T changes in the VIS/NIR to leaf physiological changes - linking the light scattered out of the drying leaf interior to its relative water content and to changes in leaf cellular structure and pigments. Our results suggest remotely sensing the physiological water status of a single leaf - and perhaps of a plant canopy - might be possible in the future.

  17. The optical polarization of X-ray binaries

    International Nuclear Information System (INIS)

    Dolan, J.F.

    1977-01-01

    Polarimetric observations of close binaries may reveal the presence of a black-hole secondary. The Einstein photometric effect will introduce a characteristic, time-varying signature upon the interstellar polarization. For several reasons, it is concluded that the short time-scale variability in the polarization in HDE 226868 is caused by Rayleigh scattering from gas streams known to exist in the system. X Persei may have a variable polarization consistent with the predicted effectics and (Auth)

  18. Control of emitted light polarization in a 1310 nm dilute nitride spin-vertical cavity surface emitting laser subject to circularly polarized optical injection

    Energy Technology Data Exchange (ETDEWEB)

    Alharthi, S. S., E-mail: ssmalh@essex.ac.uk; Hurtado, A.; Al Seyab, R. K.; Henning, I. D.; Adams, M. J. [School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester CO4 3SQ (United Kingdom); Korpijarvi, V.-M.; Guina, M. [Optoelectronics Research Centre (ORC), Tampere University of Technology, P.O. Box 692, FIN-33101 Tampere (Finland)

    2014-11-03

    We experimentally demonstrate the control of the light polarization emitted by a 1310 nm dilute nitride spin-Vertical Cavity Surface Emitting Laser (VCSEL) at room temperature. This is achieved by means of a combination of polarized optical pumping and polarized optical injection. Without external injection, the polarization of the optical pump controls that of the spin-VCSEL. However, the addition of the externally injected signal polarized with either left- (LCP) or right-circular polarization (RCP) is able to control the polarization of the spin-VCSEL switching it at will to left- or right-circular polarization. A numerical model has been developed showing a very high degree of agreement with the experimental findings.

  19. Polarization contrast in reflection near-field optical microscopy with uncoated fibre tips

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Langbein, Wolfgang; Hvam, Jørn Märcher

    1999-01-01

    Using cross-hatched, patterned semiconductor surfaces and round 20-nm-thick gold pads on semiconductor wafers, we investigate the imaging characteristics of a reflection near-field optical microscope with an uncoated fibre tip for different polarization configurations and light wavelengths....... Is is shown that cross-polarized detection allows one to effectively suppress far-field components in the detected signal and to realise imaging of optical contrast on the sub-wavelength scale. The sensitivity window of our microscope, i.e. the scale on which near-field optical images represent mainly optical...

  20. Holographic Raman Tweezers Controlled by Hand Gestures and Voice Commands

    Czech Academy of Sciences Publication Activity Database

    Tomori, Z.; Antalík, M.; Kesa, P.; Kaňka, Jan; Jákl, Petr; Šerý, Mojmír; Bernatová, Silvie; Zemánek, Pavel

    2013-01-01

    Roč. 3, 2B (2013), s. 331-336 ISSN 2160-8881 Institutional support: RVO:68081731 Keywords : Holographic Optical Tweezers * Raman Tweezers * Natural User Interface * Leap Motion * Gesture Camera Subject RIV: BH - Optics, Masers, Lasers

  1. LIMITS ON OPTICAL POLARIZATION DURING THE PROMPT PHASE OF GRB 140430A

    Energy Technology Data Exchange (ETDEWEB)

    Kopac, D.; Mundell, C. G.; Arnold, D. M.; Steele, I. A.; Kobayashi, S.; Lamb, G. P.; Smith, R. J.; Virgili, F. J. [Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool, L3 5RF (United Kingdom); Japelj, J.; Gomboc, A. [Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana (Slovenia); Guidorzi, C.; Dichiara, S. [Department of Physics and Earth Sciences, University of Ferrara, via Saragat 1, I-44122, Ferrara (Italy); Harrison, R. M. [Department of Astrophysics, School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel); Melandri, A. [INAF—Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate (Italy); Castro-Tirado, A. J.; Gorosabel, J.; Sánchez-Ramírez, R.; Oates, S. R. [Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomia s/n, E-18008 Granada (Spain); Järvinen, A. [AIP—Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany); Jelínek, M., E-mail: drejc.kopac@fmf.uni-lj.si [ASU-CAS—Astronomical Institute of the Czech Academy of Sciences, Fričova 298, 251 65 Ondřejov (Czech Republic)

    2015-11-01

    Gamma-ray burst GRB 140430A was detected by the Swift satellite and observed promptly with the imaging polarimeter RINGO3 mounted on the Liverpool Telescope, with observations beginning while the prompt γ-ray emission was still ongoing. In this paper, we present densely sampled (10-s temporal resolution) early optical light curves (LCs) in 3 optical bands and limits to the degree of optical polarization. We compare optical, X-ray, and gamma-ray properties and present an analysis of the optical emission during a period of high-energy flaring. The complex optical LC cannot be explained merely with a combination of forward and reverse shock emission from a standard external shock, implying additional contribution of emission from internal shock dissipation. We estimate an upper limit for time averaged optical polarization during the prompt phase to be as low as P < 12% (1σ). This suggests that the optical flares and early afterglow emission in this GRB are not highly polarized. Alternatively, time averaging could mask the presence of otherwise polarized components of distinct origin at different polarization position angles.

  2. LIMITS ON OPTICAL POLARIZATION DURING THE PROMPT PHASE OF GRB 140430A

    International Nuclear Information System (INIS)

    Kopac, D.; Mundell, C. G.; Arnold, D. M.; Steele, I. A.; Kobayashi, S.; Lamb, G. P.; Smith, R. J.; Virgili, F. J.; Japelj, J.; Gomboc, A.; Guidorzi, C.; Dichiara, S.; Harrison, R. M.; Melandri, A.; Castro-Tirado, A. J.; Gorosabel, J.; Sánchez-Ramírez, R.; Oates, S. R.; Järvinen, A.; Jelínek, M.

    2015-01-01

    Gamma-ray burst GRB 140430A was detected by the Swift satellite and observed promptly with the imaging polarimeter RINGO3 mounted on the Liverpool Telescope, with observations beginning while the prompt γ-ray emission was still ongoing. In this paper, we present densely sampled (10-s temporal resolution) early optical light curves (LCs) in 3 optical bands and limits to the degree of optical polarization. We compare optical, X-ray, and gamma-ray properties and present an analysis of the optical emission during a period of high-energy flaring. The complex optical LC cannot be explained merely with a combination of forward and reverse shock emission from a standard external shock, implying additional contribution of emission from internal shock dissipation. We estimate an upper limit for time averaged optical polarization during the prompt phase to be as low as P < 12% (1σ). This suggests that the optical flares and early afterglow emission in this GRB are not highly polarized. Alternatively, time averaging could mask the presence of otherwise polarized components of distinct origin at different polarization position angles

  3. Vector optical fields with polarization distributions similar to electric and magnetic field lines.

    Science.gov (United States)

    Pan, Yue; Li, Si-Min; Mao, Lei; Kong, Ling-Jun; Li, Yongnan; Tu, Chenghou; Wang, Pei; Wang, Hui-Tian

    2013-07-01

    We present, design and generate a new kind of vector optical fields with linear polarization distributions modeling to electric and magnetic field lines. The geometric configurations of "electric charges" and "magnetic charges" can engineer the spatial structure and symmetry of polarizations of vector optical field, providing additional degrees of freedom assisting in controlling the field symmetry at the focus and allowing engineering of the field distribution at the focus to the specific applications.

  4. Extreme-scale alignments of quasar optical polarizations and Galactic dust contamination

    OpenAIRE

    Pelgrims, Vincent

    2017-01-01

    Almost twenty years ago the optical polarization vectors from quasars were shown to be aligned over extreme-scales. That evidence was later confirmed and enhanced thanks to additional optical data obtained with the ESO instrument FORS2 mounted on the VLT, in Chile. These observations suggest either Galactic foreground contamination of the data or, more interestingly, a cosmological origin. Using 353-GHz polarization data from the Planck satellite, I recently showed that the main features of t...

  5. Extracting structural features of rat sciatic nerve using polarization-sensitive spectral domain optical coherence tomography

    NARCIS (Netherlands)

    Islam, M.S.; Oliveira, M.C.; Wang, Y.; Henry, F.P.; Randolph, M.A.; Park, B. H.; de Boer, J.F.

    2012-01-01

    We present spectral domain polarization-sensitive optical coherence tomography (SD PS-OCT) imaging of peripheral nerves. Structural and polarization-sensitive OCT imaging of uninjured rat sciatic nerves was evaluated both qualitatively and quantitatively. OCT and its functional extension, PS-OCT,

  6. A high field optical-pumping spin-exchange polarized deuterium source

    International Nuclear Information System (INIS)

    Coulter, K.P.; Holt, R.J.; Kinney, E.R.; Kowalczyk, R.S.; Poelker, M.; Potterveld, D.H.; Young, L.; Zeidman, B.; Toporkov, D.

    1992-01-01

    Recent results from a prototype high field optical-pumping spin-exchange polarized deuterium source are presented. Atomic polarization as high as 62% have been observed with an intensity of 6.3 x 10 17 atoms-sec -1 and 65% dissociation fraction

  7. Rydberg atoms in circular polarization: Classical stabilization in optical frequency fields

    International Nuclear Information System (INIS)

    Chism, Will; Reichl, L.E.

    2002-01-01

    We investigate the classical dynamics of the Rydberg atom in circularly polarized laser fields, restricted to the two-dimensional plane of polarization. We use a Poincare surface of section to study nonlinear resonance structures for optical frequency driving fields. We demonstrate the existence and morphology of these structures as the laser intensity transitions from moderate to intense

  8. FDTD simulation of trapping nanowires with linearly polarized and radially polarized optical tweezers.

    Science.gov (United States)

    Li, Jing; Wu, Xiaoping

    2011-10-10

    In this paper a model of the trapping force on nanowires is built by three dimensional finite-difference time-domain (FDTD) and Maxwell stress tensor methods, and the tightly focused laser beam is expressed by spherical vector wave functions (VSWFs). The trapping capacities on nanoscale-diameter nanowires are discussed in terms of a strongly focused linearly polarized beam and radially polarized beam. Simulation results demonstrate that the radially polarized beam has higher trapping efficiency on nanowires with higher refractive indices than linearly polarized beam.

  9. Polarization modulational instability in a birefringent optical fiber ...

    Indian Academy of Sciences (India)

    We obtain conditions for the occurrence of polarization modulational instability in the anomalous and normal dispersion regimes for the coupled nonlinear Schrödinger equation modelling fourth order dispersion effects when the linearly polarized pump is oriented at arbitrary angles with respect to the slow and fast axes of ...

  10. Quantum reconstruction of an intense polarization squeezed optical state

    DEFF Research Database (Denmark)

    Marquardt, Ch.; Heersink, J.; Dong, R.

    2007-01-01

    We perform a reconstruction of the polarization sector of the density matrix of an intense polarization squeezed beam starting from a complete set of Stokes measurements. By using an appropriate quasidistribution, we map this onto the Poincare space, providing a full quantum mechanical characteri...

  11. Polarization effects in silicon-clad optical waveguides

    Science.gov (United States)

    Carson, R. F.; Batchman, T. E.

    1984-01-01

    By changing the thickness of a semiconductor cladding layer deposited on a planar dielectric waveguide, the TE or TM propagating modes may be selectively attenuated. This polarization effect is due to the periodic coupling between the lossless propagating modes of the dielectric slab waveguide and the lossy modes of the cladding layer. Experimental tests involving silicon claddings show high selectivity for either polarization.

  12. Analysis of CMOS Compatible Cu-Based TM-Pass Optical Polarizer

    KAUST Repository

    Ng, Tien Khee

    2012-02-10

    A transverse-magnetic-pass (TM-pass) optical polarizer based on Cu complementary metal-oxide-semiconductor technology platform is proposed and analyzed using the 2-D method-of-lines numerical model. In designing the optimum configuration for the polarizer, it was found that the metal-insulator-metal (MIM) polarizer structure is superior compared to the insulator-metal-insulator polarizer structure due to its higher polarization extinction ratio (PER) and low insertion loss. An optimized MIM TM-pass polarizer exhibits simulated long wavelength pass filter characteristics of > ?1.2 ?m, with fundamental TM 0 and TE 0 mode transmissivity of >70% and <5%, respectively, and with PER ?11.5 dB in the wavelength range of 1.2-1.6 ?m. The subwavelength and submicrometer features of this TM-polarizer are potentially suitable for compact and low power photonics integrated circuit implementation on silicon-based substrates. © 1989-2012 IEEE.

  13. Optically Polarized Conduction-Band Electrons in Tungsten Observed by Spin-Polarized Photoemission

    DEFF Research Database (Denmark)

    Zürcher, P.; Meier, F.; Christensen, N. E.

    1979-01-01

    Along the (100) direction of tungsten, interband transitions induced by circularly polarized light of energy 1.5 eV......Along the (100) direction of tungsten, interband transitions induced by circularly polarized light of energy 1.5 eV...

  14. Prospects for a deuterium internal target, tensor polarized by optical pumping: spin exchange

    International Nuclear Information System (INIS)

    Green, M.C.

    1984-01-01

    The prospects for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) appropriate for nuclear physics studies in medium and high energy particle storage rings are discussed. Using the technique of electron spin exchange with an optically pumped sodium (or potassium) vapor, we hope to polarize deuterium at a rate approx. 10 17 atoms/sec. Predictions for the deuterium polarization for a particular target cell design will be presented leading to the identification of the required optical pumping power and cell wall depolarization probability to attain optimum performance. The technical obstacles to be surmounted in such a target design will also be discussed

  15. Non-uniformly polarized beams across their transverse profiles: an introductory study for undergraduate optics courses

    International Nuclear Information System (INIS)

    Piquero, Gemma; Vargas-Balbuena, Javier

    2004-01-01

    We provide a simple theoretical study of beams non-uniformly polarized across their transverse sections which can be introduced in undergraduate optics courses. In order to generate such beams we propose to use a slightly convergent (or divergent) linearly and uniformly polarized beam impinging on an anisotropic uniaxial material with the beam propagation direction along the optic axis. Analytical expressions for the Jones vector, Stokes parameters, ellipticity and azimuth at each point of the transverse section, perpendicular to the propagation direction, are obtained at the output of this system. By means of these parameters a detailed description of the state of polarization across the transverse profile is given

  16. Optical field-strength polarization of two-mode single-photon states

    Energy Technology Data Exchange (ETDEWEB)

    Linares, J; Nistal, M C; Barral, D; Moreno, V, E-mail: suso.linares.beiras@usc.e [Optics Area, Department of Applied Physics, Faculty of Physics and School of Optics and Optometry, University of Santiago de Compostela, Campus Universitario Sur s/n, 15782-Santiago de Compostela, Galicia (Spain)

    2010-09-15

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of the two-mode optical field-strength plane. We will show that the mentioned probability distributions along with the values of quantum Stokes parameters allow us to characterize the polarization of a two-mode single-photon state, in an analogous way to the classical case, and to distinguish conceptually between mixture and partially polarized quantum states; in this way, we propose a simple definition of the quantum polarization degree based on the recent concept of distance measure to an unpolarized distribution, which gives rise to a depolarization degree equivalent to an overlapping between the probability distribution of the quantum state and a non-polarized two-mode Gaussian distribution. The work is particularly intended to university physics teachers and graduate students as well as to physicists and specialists concerned with the issue of optical polarization.

  17. Optical field-strength polarization of two-mode single-photon states

    International Nuclear Information System (INIS)

    Linares, J; Nistal, M C; Barral, D; Moreno, V

    2010-01-01

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of the two-mode optical field-strength plane. We will show that the mentioned probability distributions along with the values of quantum Stokes parameters allow us to characterize the polarization of a two-mode single-photon state, in an analogous way to the classical case, and to distinguish conceptually between mixture and partially polarized quantum states; in this way, we propose a simple definition of the quantum polarization degree based on the recent concept of distance measure to an unpolarized distribution, which gives rise to a depolarization degree equivalent to an overlapping between the probability distribution of the quantum state and a non-polarized two-mode Gaussian distribution. The work is particularly intended to university physics teachers and graduate students as well as to physicists and specialists concerned with the issue of optical polarization.

  18. Optical pumping and negative luminescence polarization in charged GaAs quantum dots

    Science.gov (United States)

    Shabaev, Andrew; Stinaff, Eric A.; Bracker, Allan S.; Gammon, Daniel; Efros, Alexander L.; Korenev, Vladimir L.; Merkulov, Igor

    2009-01-01

    Optical pumping of electron spins and negative photoluminescence polarization are observed when interface quantum dots in a GaAs quantum well are excited nonresonantly by circularly polarized light. Both observations can be explained by the formation of long-lived dark excitons through hole spin relaxation in the GaAs quantum well prior to exciton capture. In this model, optical pumping of resident electron spins is caused by capture of dark excitons and recombination in charged quantum dots. Negative polarization results from accumulation of dark excitons in the quantum well and is enhanced by optical pumping. The dark exciton model describes the experimental results very well, including intensity and bias dependence of the photoluminescence polarization and the Hanle effect.

  19. Plasmonic Dimer Metamaterials and Metasurfaces for Polarization Control of Terahertz and Optical Waves

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Zalkovskij, Maksim; Malureanu, Radu

    2013-01-01

    We explore the capabilities of planar metamaterials and metasurfaces to control and transform the polarization of electromagnetic radiation, and present a detailed covariant multipole theory of dimer-based metamaterials. We show that various optical properties, such as optical activity, elliptical...... dichroism or polarization conversion can be achieved in metamaterials made of simple shapes, such as nanorods, just by varying their geometrical arrangement. By virtue of the Babinet principle, the proposed theory is extended to inverted structures (membranes) where rods are replaced by slots. Such free......-standing “metasurface membranes” can act as thin-film spectrally sensitive polarization shapers for THz radiation. Proof-of-principle devices (a linear polarizer and a structure with giant optical activity) are fabricated and characterized. Experimental results coincide with those of full-wave numerical simulations...

  20. Effect of a spiral phase on a vector optical field with hybrid polarization states

    International Nuclear Information System (INIS)

    Chen, Rui-Pin; Zhao, Tingyu; Zhong, Li-Xin; Chew, Khian-Hooi; Gu, Bing; Zhou, Guoquan

    2015-01-01

    The propagation dynamics of a vector field with inhomogeneous states of polarization (SoP) imposed a vortex is studied using the angular spectrum method. The evolution of SoP in the cross section of the field during propagation is analyzed numerically by the Stokes polarization parameters. The results indicate that SoP in the field cross section rotate along the propagation axis during propagation due to the existence of a vortex. In addition, the interaction between the phase singularity and the polarization singularity leads to the creation or annihilation of the optical field in the central region. In particular, the distributions of the transverse energy flow and both spin and orbital optical angular momentum fluxes in the cross section of the vortex vector optical field depend sensitively on both the vortex and polarization topology charges. (paper)

  1. Optical asymmetric cryptography based on amplitude reconstruction of elliptically polarized light

    Science.gov (United States)

    Cai, Jianjun; Shen, Xueju; Lei, Ming

    2017-11-01

    We propose a novel optical asymmetric image encryption method based on amplitude reconstruction of elliptically polarized light, which is free from silhouette problem. The original image is analytically separated into two phase-only masks firstly, and then the two masks are encoded into amplitudes of the orthogonal polarization components of an elliptically polarized light. Finally, the elliptically polarized light propagates through a linear polarizer, and the output intensity distribution is recorded by a CCD camera to obtain the ciphertext. The whole encryption procedure could be implemented by using commonly used optical elements, and it combines diffusion process and confusion process. As a result, the proposed method achieves high robustness against iterative-algorithm-based attacks. Simulation results are presented to prove the validity of the proposed cryptography.

  2. Optically-driven red blood cell rotor in linearly polarized laser tweezers

    Indian Academy of Sciences (India)

    We have constructed a dual trap optical tweezers set-up around an inverted microscope where both the traps can be independently controlled and manipulated in all the three dimensions. Here we report our observations on rotation of red blood cells (RBCs) in a linearly polarized optical trap. Red blood cells deform and ...

  3. Developments in holographic-based scanner designs

    Science.gov (United States)

    Rowe, David M.

    1997-07-01

    Holographic-based scanning systems have been used for years in the high resolution prepress markets where monochromatic lasers are generally utilized. However, until recently, due to the dispersive properties of holographic optical elements (HOEs), along with the high cost associated with recording 'master' HOEs, holographic scanners have not been able to penetrate major scanning markets such as the laser printer and digital copier markets, low to mid-range imagesetter markets, and the non-contact inspection scanner market. Each of these markets has developed cost effective laser diode based solutions using conventional scanning approaches such as polygon/f-theta lens combinations. In order to penetrate these markets, holographic-based systems must exhibit low cost and immunity to wavelength shifts associated with laser diodes. This paper describes recent developments in the design of holographic scanners in which multiple HOEs, each possessing optical power, are used in conjunction with one curved mirror to passively correct focal plane position errors and spot size changes caused by the wavelength instability of laser diodes. This paper also describes recent advancements in low cost production of high quality HOEs and curved mirrors. Together these developments allow holographic scanners to be economically competitive alternatives to conventional devices in every segment of the laser scanning industry.

  4. Design of polarization encoded all-optical 4-valued MAX logic gate and its applications

    Science.gov (United States)

    Chattopadhyay, Tanay; Nath Roy, Jitendra

    2013-07-01

    Quaternary maximum (QMAX) gate is one type of multi-valued logic gate. An all-optical scheme of polarization encoded quaternary (4-valued) MAX logic gate with the help of Terahertz Optical Asymmetric Demultiplexer (TOAD) based fiber interferometric switch is proposed and described. For the quaternary information processing in optics, the quaternary number (0, 1, 2, 3) can be represented by four discrete polarized states of light. Numerical simulation result confirming the described methods is given in this paper. Some applications of MAX gate in logical operation and memory device are also given.

  5. Polarization ray tracing in anisotropic optically active media. II. Theory and physics

    International Nuclear Information System (INIS)

    McClain, S.C.; Hillman, L.W.; Chipman, R.A.

    1993-01-01

    Refraction, reflection, and amplitude relations are derived that apply to polarization ray tracing in anisotropic, optically active media such as quartz. The constitutive relations for quartz are discussed. The refractive indices and polarization states associated with the two modes of propagation are derived as a function of wave direction. A procedure for refracting at any uniaxial or optically active interface is derived that computes both the ray direction and the wave direction. A method for computing the optical path length is given, and Fresnel transmission and ref lection equations are derived from boundary conditions on the electromagnetic fields. These ray-tracing formulas apply to uniaxial, optically active media and therefore encompass uniaxial, non-optically active materials and isotropic, optically active materials

  6. Polarization encoded all-optical quaternary successor with the help of SOA assisted Sagnac switch

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath

    2011-06-01

    The application of multi-valued (non-binary) signals can provide a considerable relief in transmission, storage and processing of large amount of information in digital signal processing. Optical multi-valued logical operation is an interesting challenge for future optical signal processing where we can expect much innovation. A novel all-optical quaternary successor (QSUC) circuit with the help of semiconductor optical amplifier (SOA)-assisted Sagnac switch is proposed and described. This circuit exploits the polarization properties of light. Different logical states are represented by different polarization state of light. Simulation result confirming described method is given in this paper. Proposed all-optical successor circuit can take an important and significant role in designing of all-optical quaternary universal inverter and modulo arithmetic unit (addition and multiplication).

  7. Mathematical modeling and experimental study of polarization echo in optically anisotropic media

    Science.gov (United States)

    Bogdanov, Yu. I.; Kalinkin, A. A.; Kulik, S. P.; Moreva, E. V.; Shershulin, V. A.; Belinsky, L. V.

    2013-01-01

    As optical systems are one of the candidates for implementation of a scalable quantum computer, it is important to develop an adequate method of description of both quantum states of light and operations performed by optical elements. Using the concept of chi-matrix representation of quantum operations and Choi-Jamiolkowski isomorphism we expand Jones calculus to allow description of evolution of mixed polarization states in linear optical systems. The developed method is then used to give a full description of polarization echo effect, which was described in 1 based on an analogy between the effects of polarization optics and spin dynamics. Theoretical predictions are confirmed by reconstructing operations performed by a series of quartz waveplates using quantum process tomography protocols.

  8. Polarization singularities of optical fields caused by structural dislocations in crystals

    International Nuclear Information System (INIS)

    Savaryn, V; Vasylkiv, Yu; Krupych, O; Skab, I; Vlokh, R

    2013-01-01

    We analyze polarization singularities of optical beams that propagate through crystals possessing structural dislocations. We show that screw dislocations of crystalline structure can lead to the appearance of purely screw-type dislocations of light wavefronts. This can happen only in crystals that belong to trigonal and cubic systems. These polarization singularities will give rise to optical vortices with the topological charge equal to ±1, whenever a crystal sample is placed between crossed circular polarizers. We have also found that edge dislocations present in the cubic and trigonal crystals, with the Burgers vector perpendicular to the three-fold symmetry axes, can impose mixed screw-edge dislocations in the wavefronts of optical beams and generate singly charged optical vortices. The results of our analysis can be applied for detecting and identifying dislocations of different types available in crystals. (paper)

  9. Polarization dependent dispersion and its impact on optical parametric process in high nonlinear microstructure fibre

    International Nuclear Information System (INIS)

    Xiao Li; Zhang Wei; Huang Yidong; Peng Jiangde

    2008-01-01

    High nonlinear microstructure fibre (HNMF) is preferred in nonlinear fibre optics, especially in the applications of optical parametric effects, due to its high optical nonlinear coefficient. However, polarization dependent dispersion will impact the nonlinear optical parametric process in HNMFs. In this paper, modulation instability (MI) method is used to measure the polarization dependent dispersion of a piece of commercial HNMF, including the group velocity dispersion, the dispersion slope, the fourth-order dispersion and group birefringence. It also experimentally demonstrates the impact of the polarization dependent dispersion on the continuous wave supercontinuum (SC) generation. On one axis MI sidebands with symmetric frequency detunings are generated, while on the other axis with larger MI frequency detuning, SC is generated by soliton self-frequency shift

  10. Apparatus and Method for Elimination of Polarization-Induced Fading in Fiber-optic Sensor System

    Science.gov (United States)

    Chan, Hon Man (Inventor); Parker, Jr., Allen R. (Inventor)

    2015-01-01

    The invention is an apparatus and method of eliminating polarization-induced fading in interferometric fiber-optic sensor system having a wavelength-swept laser optical signal. The interferometric return signal from the sensor arms are combined and provided to a multi-optical path detector assembly and ultimately to a data acquisition and processing unit by way of a switch that is time synchronized with the laser scan sweep cycle.

  11. Optical properties of polarization-dependent geometrical phase elements with partially polarized light

    International Nuclear Information System (INIS)

    Gorodetski, Y.; Biener, G.; Niv, A.; Kleiner, V.; Hasman, E.

    2005-01-01

    Full Text:The behavior of geometrical phase elements illuminated with partially polarized monochromatic beams is being theoretically as well as experimentally investigated. The element discussed in this paper is composed of wave plates with retardation and space-variant orientation angle. We found that a beam emerging from such an element comprises two polarization orders of right and left-handed circularly polarized states with conjugate geometrical phase modification. This phase equals twice the orientation angle of the space-variant wave plate comprising the element. Apart from the two polarization orders, the emerging beam coherence polarization matrix comprises a matrix termed as the vectorial interference matrix. This matrix contains the information concerning the correlation between the two orthogonal circularly polarized portions of the incident beam. In this paper we measure this correlation by a simple interference experiment. Furthermore, we found that the equivalent mutual intensity of the emerging beam is being modulated according to the geometrical phase induced by the element. Other interesting phenomena along propagation will be discussed theoretically and experimentally demonstrated. We demonstrate experimentally our analysis by using a spherical geometrical phase element, which is realized by use of space-variant sub wavelength grating and illuminated with a CO 2 laser radiation of 10.6μm wavelength

  12. Nuclear spin polarized H and D by means of spin-exchange optical pumping

    Science.gov (United States)

    Stenger, Jörn; Grosshauser, Carsten; Kilian, Wolfgang; Nagengast, Wolfgang; Ranzenberger, Bernd; Rith, Klaus; Schmidt, Frank

    1998-01-01

    Optically pumped spin-exchange sources for polarized hydrogen and deuterium atoms have been demonstrated to yield high atomic flow and high electron spin polarization. For maximum nuclear polarization the source has to be operated in spin temperature equilibrium, which has already been demonstrated for hydrogen. In spin temperature equilibrium the nuclear spin polarization PI equals the electron spin polarization PS for hydrogen and is even larger than PS for deuterium. We discuss the general properties of spin temperature equilibrium for a sample of deuterium atoms. One result are the equations PI=4PS/(3+PS2) and Pzz=PSṡPI, where Pzz is the nuclear tensor polarization. Furthermore we demonstrate that the deuterium atoms from our source are in spin temperature equilibrium within the experimental accuracy.

  13. Wavelength Dependence of the Polarization Singularities in a Two-Mode Optical Fiber

    Directory of Open Access Journals (Sweden)

    V. V. G. Krishna Inavalli

    2012-01-01

    Full Text Available We present here an experimental demonstration of the wavelength dependence of the polarization singularities due to linear combination of the vector modes excited directly in a two-mode optical fiber. The coherent superposition of the vector modes excited by linearly polarized Gaussian beam as offset skew rays propagated in a helical path inside the fiber results in the generation of phase singular beams with edge dislocation in the fiber output. The polarization character of these beams is found to change dramatically with wavelength—from left-handed elliptically polarized edge dislocation to right-handed elliptically polarized edge-dislocation through disclinations. The measured behaviour is understood as being due to intermodal dispersion of the polarization corrections to the propagating vector modes, as the wavelength of the input beam is scanned.

  14. Intense source of spin-polarized electrons using laser-induced optical pumping

    International Nuclear Information System (INIS)

    Gray, L.G.; Giberson, K.W.; Cheng, C.; Keiffer, R.S.; Dunning, F.B.; Walters, G.K.

    1983-01-01

    A source of spin-polarized electrons based on a laser-pumped flowing helium afterglow is described. He(2 3 S) atoms contained in the afterglow are optically pumped using circularly polarized 1.08-μm (2 3 S→2 3 P) radiation provided by a NaF (F 2+ )( color-center laser. Spin angular momentum conservation in subsequent chemi-ionization reactions with CO 2 produces polarized electrons that are extracted from the afterglow. At low currents, < or approx. =1 μA, polarizations of approx.70%--80% are achieved. At higher currents the polarization decreases, falling to approx.40% at 50 μA. The spin polarization can be simply reversed (P→-P) and the source is suitable for use in the majority of low-energy spin-dependent scattering experiments proposed to date

  15. Polarized excitons and optical activity in single-wall carbon nanotubes

    Science.gov (United States)

    Chang, Yao-Wen; Jin, Bih-Yaw

    2018-05-01

    The polarized excitons and optical activity of single-wall carbon nanotubes (SWNTs) are studied theoretically by π -electron Hamiltonian and helical-rotational symmetry. By taking advantage of the symmetrization, the single-particle energy and properties of a SWNT are characterized with the corresponding helical band structure. The dipole-moment matrix elements, magnetic-moment matrix elements, and the selection rules can also be derived. Based on different selection rules, the optical transitions can be assigned as the parallel-polarized, left-handed circularly-polarized, and right-handed circularly-polarized transitions, where the combination of the last two gives the cross-polarized transition. The absorption and circular dichroism (CD) spectra are simulated by exciton calculation. The calculated results are well comparable with the reported measurements. Built on the foundation, magnetic-field effects on the polarized excitons and optical activity of SWNTs are studied. Dark-bright exciton splitting and interband Faraday effect in the CD spectrum of SWNTs under an axial magnetic field are predicted. The Faraday rotation dispersion can be analyzed according to the selection rules of circular polarizations and the helical band structure.

  16. Optically active Babinet planar metamaterial film for terahertz polarization manipulation

    DEFF Research Database (Denmark)

    Zalkovskij, Maksim; Malureanu, Radu; Kremers, C.

    2013-01-01

    A planar Babinet-inverted dimer metamaterial possessing strong optical activity is proposed and characterized. An original fabrication method to produce large area (up to several cm2) freely suspended flexible metallic membranes is implemented to fabricate the metamaterial. Its optical properties...

  17. 3D holographic polymer photonic crystal for superprism application

    Science.gov (United States)

    Chen, Jiaqi; Jiang, Wei; Chen, Xiaonan; Wang, Li; Zhang, Sasa; Chen, Ray T.

    2007-02-01

    Photonic crystal based superprism offers a new way to design new optical components for beam steering and DWDM application. 3D photonic crystals are especially attractive as they could offer more control of the light beam based on the needs. A polygonal prism based holographic fabrication method has been demonstrated for a three-dimensional face-centered-cubic (FCC)-type submicron polymer photonic crystal using SU8 as the photo-sensitive material. Therefore antivibration equipment and complicated optical alignment system are not needed and the requirement for the coherence of the laser source is relaxed compared with the traditional holographic setup. By changing the top-cut prism structure, the polarization of the laser beam, the exposure and development conditions we can achieve different kinds of triclinic or orthorhombic photonic crystals on demand. Special fabrication treatments have been introduced to ensure the survivability of the fabricated large area (cm2) nano-structures. Scanning electron microscopy and diffraction results proved the good uniformity of the fabricated structures. With the proper design of the refraction prism we have achieved a partial bandgap for S+C band (1460-1565nm) in the [111] direction. The transmission and reflection spectra obtained by Fourier transform infrared spectroscopy (FTIR) are in good agreement with simulated band structure. The superprism effects around 1550nm wavelength for the fabricated 3D polymer photonic crystal have been theoretically calculated and such effects can be used for beam steering purpose.

  18. Towards all-dielectric, polarization-independent optical cloaks

    DEFF Research Database (Denmark)

    Andkjær, Jacob Anders; Mortensen, N. Asger; Sigmund, Ole

    2012-01-01

    Fully enclosing, all-dielectric cloaks working for both E-z and H-z polarizations simultaneously are presented in this letter. The cloaks are effective for two antiparallel angles of incidence, and the layout of standard dielectric material in the cloak is determined by topology optimization. Sca...... effectively when distributing a material with lower permittivity than the background material....

  19. Circular polarization in the optical afterglow of GRB 121024A

    NARCIS (Netherlands)

    Wiersema, K.; Covino, S.; Toma, K.; van der Horst, A.J.; Varela, K.; Min, M.; Greiner, J.; Starling, R.L.C.; Tanvir, N.R.; Wijers, R.A.M.J.; Campana, S.; Curran, P.A.; Fan, Y.; Fynbo, J.P.U.; Gorosabel, J.; Gomboc, A.; Götz, D.; Hjorth, J.; Jin, Z.P.; Kobayashi, S.; Kouveliotou, C.; Mundell, C.; O’Brien, P.T.; Pian, E.; Rowlinson, A.; Russell, D.M.; Salvaterra, R.; di Serego Alighieri, S.; Tagliaferri, G.; Vergani, S.D.; Elliott, J.; Fariña, C.; Hartoog, O.E.; Karjalainen, R.; Klose, S.; Knust, F.; Levan, A.J.; Schady, P.; Sudilovsky, V.; Willingale, R.

    2014-01-01

    Gamma-ray bursts (GRBs) are most probably powered by collimated relativistic outflows (jets) from accreting black holes at cosmological distances. Bright afterglows are produced when the outflow collides with the ambient medium. Afterglow polarization directly probes the magnetic properties of the

  20. Circular polarization in the optical afterglow of GRB 121024A

    DEFF Research Database (Denmark)

    Wiersema, K.; Covino, S.; Toma, K.

    2014-01-01

    Gamma-ray bursts (GRBs) are most probably powered by collimated relativistic outflows (jets) from accreting black holes at cosmological distances. Bright afterglows are produced when the outflow collides with the ambient medium. Afterglow polarization directly probes the magnetic properties of th...

  1. Polarization-preserving confocal microscope for optical experiments in a dilution refrigerator with high magnetic field.

    Science.gov (United States)

    Sladkov, Maksym; Bakker, M P; Chaubal, A U; Reuter, D; Wieck, A D; van der Wal, C H

    2011-04-01

    We present the design and operation of a fiber-based cryogenic confocal microscope. It is designed as a compact cold-finger that fits inside the bore of a superconducting magnet, and which is a modular unit that can be easily swapped between use in a dilution refrigerator and other cryostats. We aimed at application in quantum optical experiments with electron spins in semiconductors and the design has been optimized for driving with and detection of optical fields with well-defined polarizations. This was implemented with optical access via a polarization maintaining fiber together with Voigt geometry at the cold finger, which circumvents Faraday rotations in the optical components in high magnetic fields. Our unit is versatile for use in experiments that measure photoluminescence, reflection, or transmission, as we demonstrate with a quantum optical experiment with an ensemble of donor-bound electrons in a thin GaAs film. © 2011 American Institute of Physics

  2. Optical asymmetric cryptography based on elliptical polarized light linear truncation and a numerical reconstruction technique.

    Science.gov (United States)

    Lin, Chao; Shen, Xueju; Wang, Zhisong; Zhao, Cheng

    2014-06-20

    We demonstrate a novel optical asymmetric cryptosystem based on the principle of elliptical polarized light linear truncation and a numerical reconstruction technique. The device of an array of linear polarizers is introduced to achieve linear truncation on the spatially resolved elliptical polarization distribution during image encryption. This encoding process can be characterized as confusion-based optical cryptography that involves no Fourier lens and diffusion operation. Based on the Jones matrix formalism, the intensity transmittance for this truncation is deduced to perform elliptical polarized light reconstruction based on two intensity measurements. Use of a quick response code makes the proposed cryptosystem practical, with versatile key sensitivity and fault tolerance. Both simulation and preliminary experimental results that support theoretical analysis are presented. An analysis of the resistance of the proposed method on a known public key attack is also provided.

  3. Initial operating experience and recent development on the TRIUMF optically pumped polarized H- ion source

    International Nuclear Information System (INIS)

    Schmor, P.W.; Law, W.M.; Levy, C.D.P.; McDonald, M.

    1988-01-01

    A polarized H - ion source using optical pumping techniques has been developed at TRIUMF. This source was used to demonstrate (on an ion source test stand) the feasibility of producing 10- μA of ∼ 60% polarized H - ion beam in a dc mode suitable for injection into the TRIUMF cyclotron. The source has been installed in a 300 kV high voltage terminal connected to the cyclotron via a recently constructed beam transport line. A polarization of 80% is anticipated near the end of 1988 after the installation of a superconducting solenoid to the source. In this paper the authors describe the initial operating experience, recent developments, and the future plans for the TRIUMF optically pumped polarized ion source

  4. Optical polarization properties of InAs/InP quantum dot and quantum rod nanowires

    International Nuclear Information System (INIS)

    Anufriev, Roman; Bru-Chevallier, Catherine; Chauvin, Nicolas; Barakat, Jean-Baptiste; Letartre, Xavier; Gendry, Michel; Patriarche, Gilles; Harmand, Jean-Christophe

    2015-01-01

    The emission polarization of single InAs/InP quantum dot (QD) and quantum rod (QR) nanowires is investigated at room temperature. Whereas the emission of the QRs is mainly polarized parallel to the nanowire axis, the opposite behavior is observed for the QDs. These optical properties can be explained by a combination of dielectric effects related to the nanowire geometry and to the configuration of the valence band in the nanostructure. A theoretical model and finite difference in time domain calculations are presented to describe the impact of the nanowire and the surroundings on the optical properties of the emitter. Using this model, the intrinsic degree of linear polarization of the two types of emitters is extracted. The strong polarization anisotropies indicate a valence band mixing in the QRs but not in the QDs. (paper)

  5. Fine structure and optical properties of biological polarizers in crustaceans and cephalopods

    Science.gov (United States)

    Chiou, Tsyr-Huei; Caldwell, Roy L.; Hanlon, Roger T.; Cronin, Thomas W.

    2008-04-01

    The lighting of the underwater environment is constantly changing due to attenuation by water, scattering by suspended particles, as well as the refraction and reflection caused by the surface waves. These factors pose a great challenge for marine animals which communicate through visual signals, especially those based on color. To escape this problem, certain cephalopod mollusks and stomatopod crustaceans utilize the polarization properties of light. While the mechanisms behind the polarization vision of these two animal groups are similar, several distinctive types of polarizers (i.e. the structure producing the signal) have been found in these animals. To gain a better knowledge of how these polarizers function, we studied the relationships between fine structures and optical properties of four types of polarizers found in cephalopods and stomatopods. Although all the polarizers share a somewhat similar spectral range, around 450- 550 nm, the reflectance properties of the signals and the mechanisms used to produce them have dramatic differences. In cephalopods, stack-plates polarizers produce the polarization patterns found on the arms and around their eyes. In stomatopods, we have found one type of beam-splitting polarizer based on photonic structures and two absorptive polarizer types based on dichroic molecules. These stomatopod polarizers may be found on various appendages, and on the cuticle covering dorsal or lateral sides of the animal. Since the efficiencies of all these polarizer types are somewhat sensitive to the change of illumination and viewing angle, how these animals compensate with different behaviors or fine structural features of the polarizer also varies.

  6. Multiplexed Holograms by Surface Plasmon Propagation and Polarized Scattering.

    Science.gov (United States)

    Chen, Ji; Li, Tao; Wang, Shuming; Zhu, Shining

    2017-08-09

    Thanks to the superiority in controlling the optical wave fronts, plasmonic nanostructures have led to various striking applications, among which metasurface holograms have been well developed and endowed with strong multiplexing capability. Here, we report a new design of multiplexed plasmonic hologram, which allows for reconstruction of multiple holographic images in free space by scatterings of surface plasmon polariton (SPP) waves in different propagation directions. Besides, the scattered polarization states can be further modulated by arranging the orientations of nanoscatterers. By incorporation of the SPP propagation and polarized scattering, a 4-fold hologram with low crosstalk is successfully demonstrated, which breaks the limitation of only two orthogonal states in conventional polarization multiplexers. Moreover, our design using the near-field SPP as reference wave holds the advantage for compact integration. This holographic approach is expected to inspire new photonic designs with enhanced information capacity and integratability.

  7. Nonlinear Fourier transform for dual-polarization optical communication system

    OpenAIRE

    Gaiarin, Simone

    2018-01-01

    New services and applications are causing an exponential increase in the internet traffic. In a few years, the current fiber-optic communication system infrastructure will not be able to meet this demand because fiber nonlinearity dramatically limits the information transmission rate. Eigenvalue communication is considered an emerging paradigm in fiber-optic communications that could potentially overcome these limitations. It relies on a mathematical technique called “inverse scattering trans...

  8. Analysis of aerosol optical depth evaluation in polar regions and associated uncertainties

    Directory of Open Access Journals (Sweden)

    P. Ortiz de Galisteo

    2008-04-01

    Full Text Available Some available processing algorithms used to calculate the aerosol optical depth from radiometric measurements were tested. The aim was to evaluate the associated uncertainties in polar regions due to the data processing, in order to adjust the methodology of the calculation and illustrate the importance of these error sources. The measurements were obtained during a sun photometer campaign in Ny-Ålesund within the framework of the POLAR-AOD project.

  9. Investigation of Beam Emittance and Beam Transport Line Optics on Polarization

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, Andrew [Northern Illinois U.; Syphers, Michael [Fermilab

    2017-10-06

    Effects of beam emittance, energy spread, optical parameters and magnet misalignment on beam polarization through particle transport systems are investigated. Particular emphasis will be placed on the beam lines being used at Fermilab for the development of the muon beam for the Muon g-2 experiment, including comparisons with the natural polarization resulting from pion decay, and comments on the development of systematic correlations among phase space variables.

  10. MASTER OPTICAL POLARIZATION VARIABILITY DETECTION IN THE MICROQUASAR V404 CYG/GS 2023+33

    Energy Technology Data Exchange (ETDEWEB)

    Lipunov, Vladimir M.; Kornilov, V.; Vlasenko, D. [M.V. Lomonosov Moscow State University, Physics Department, Leninskie gory, GSP-1, Moscow, 119991 (Russian Federation); Gorbovskoy, E.; Tiurina, N.; Balanutsa, P.; Kuznetsov, A. [M.V. Lomonosov Moscow State University, Sternberg Astronomical Institute, Universitetsky pr., 13, Moscow, 119234 (Russian Federation); Krushinskiy, V. [Kourovka Astronomical Observatory, Ural Federal University, Lenin ave. 51, Ekaterinburg 620000 (Russian Federation); Budnev, N.; Gress, O.; Ivanov, K.; Yazev, S. [Applied Physics Institute, Irkutsk State University, 20, Gagarin blvd, 664003, Irkutsk (Russian Federation); Tlatov, A. [Kislovodsk Solar Station of the Main (Pulkovo) Observatory RAS, P.O. Box 45, ul. Gagarina 100, Kislovodsk 357700 (Russian Federation); Rebolo Lopez, R.; Serra-Ricart, M.; Israelyan, G.; Lodieu, N. [Instituto de Astrofsica de Canarias, C/Via Lctea, s/n E-38205, La Laguna, Tenerife (Spain); Buckley, D. A. H. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Sergienko, Yu.; Gabovich, A. [Blagoveschensk State Pedagogical University, Lenin str., 104, Amur Region, Blagoveschensk 675000 (Russian Federation); and others

    2016-12-20

    On 2015 June 15, the Swift space observatory discovered that the Galactic black hole candidate V404 Cyg was undergoing another active X-ray phase, after 25 years of inactivity. The 12 telescopes of the MASTER Global Robotic Net located at six sites across four continents were the first ground-based observatories to start optical monitoring of the microquasar after its gamma-ray wake up at 18{sup h} 34{sup m} 09{sup s} U.T. on 2015 June 15. In this paper, we report, for the first time, the discovery of variable optical linear polarization, changing by 4%–6% over a timescale of ∼1 hr, on two different epochs. We can conclude that the additional variable polarization arises from the relativistic jet generated by the black hole in V404 Cyg. The polarization variability correlates with optical brightness changes, increasing when the flux decreases.

  11. TE-TM dynamics in a semiconductor laser subject to polarization-rotated optical feedback

    International Nuclear Information System (INIS)

    Heil, T.; Uchida, A.; Davis, P.; Aida, T.

    2003-01-01

    We present a comprehensive experimental characterization of the dynamics of semiconductor lasers subject to polarization-rotated optical feedback. We find oscillatory instabilities appearing for large feedback levels and disappearing at large injection currents, which we classify in contrast to the well-known conventional optical-feedback-induced dynamics. In addition, we compare our experiments to theoretical results of a single-mode model assuming incoherence of the optical feedback, and we identify differences concerning the average power of the laser. Hence, we develop an alternative model accounting for both polarizations, where the emission of the dominant TE mode is injected with delay into the TM mode of the laser. Numerical simulations using this model show good qualitative agreement with our experimental results, correctly reproducing the parameter dependences of the dynamics. Finally, we discuss the application of polarization-rotated-feedback induced instabilities in chaotic carrier communication systems

  12. Development and demonstration of optical polarization controller; Hikari henpa seigyo sochi no kaihatsu to jissho

    Energy Technology Data Exchange (ETDEWEB)

    Kurono, M. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1997-04-01

    If fiber transmission light can be controlled in a stabilized polarization state, realization of coherent optical communication is anticipated. In the case of adopting it to OPGW, however, it is necessary to compensate high speed polarization variation caused by lightning strike. But this was difficult in the conventional method. Accordingly, a high speed polarization control method was proposed which uses an electric effect of lithium niobate (LN) crystals. In the study, a polarization control unit was manufactured based on the method proposed and the performance was demonstrated. As a result of measuring output light with input light changed in every state of polarization, the object horizontal polarization component obtained a stabilized light intensity at {+-}0.1dB, and a light intensity of the component slipped out of the horizontal polarization was suppressed under -20dB. To cope with the polarization variation by lightning strike, it is necessary to make the control delay 10{mu}sec or below, and improvement in processing unit, etc. may make it possible since LN crystals respond below 1{mu}sec. High speed control of the infinitely continuing arbitrary polarization variation became possible. 14 refs., 19 figs.

  13. Optical Polarization as a Probe of the Local Interstellar Medium

    Science.gov (United States)

    Tinbergen, J.

    1984-01-01

    The use of interstellar polarization as a tool for measuring interstellar dust is discussed. Problems resulting from dust and magnetic field configurations becoming mixed up are discussed, as is the availability of sufficiently bright stars to obtain the photons needed for precision measurements. It is proposed that: (1) on the scale of several hundred parsec, there is a preferential magnetic field direction, as evidenced by observations at the Galactic poles and selected longitudes in the Galactic plane; (2) the local (r 50 pc) region is devoid of dust, as evidenced by the mean square degree of polarization as a function of distance; and, less certainly, that (3) at a distance of less than 5 pc, there is a patch of dust which may be of interest in connection with cloud models.

  14. Circularly polarized light to study linear magneto-optics for ferrofluids: θ-scan technique

    Science.gov (United States)

    Meng, Xiangshen; Huang, Yan; He, Zhenghong; Lin, Yueqiang; Liu, Xiaodong; Li, Decai; Li, Jian; Qiu, Xiaoyan

    2018-06-01

    Circularly polarized light can be divided into two vertically linearly polarized light beams with  ±π/2 phase differences. In the presence of an external magnetic field, when circularly polarized light travels through a ferrofluid film, whose thickness is no more than that of λ/4 plate, magneto-optical, magnetic birefringence and dichroism effects cause the transmitted light to behave as elliptically polarized light. Using angular scan by a continuously rotating polarizer as analyzer, the angular (θ) distribution curve of relative intensity (T) corresponding to elliptically polarized light can be measured. From the T  ‑  θ curve having ellipsometry, the parameters such as the ratio of short to long axis, and angular orientation of the long axis to the vertical field direction can be obtained. Thus, magnetic birefringence and dichroism can be probed simultaneously by measuring magneto-optical, positive or negative birefringence and dichroism features from the transmission mode. The proposed method is called θ-scan technique, and can accurately determine sample stability, magnetic field direction, and cancel intrinsic light source ellipticity. This study may be helpful to further research done to ferrofluids and other similar colloidal samples with anisotropic optics.

  15. Optical refraction index and polarization profile of ferroelectric thin films

    Czech Academy of Sciences Publication Activity Database

    Glinchuk, M. D.; Eliseev, E. A.; Deineka, Alexander; Jastrabík, Lubomír; Suchaneck, G.; Sandner, T.; Gerlach, G.; Hrabovský, Miroslav

    2001-01-01

    Roč. 38, 1-4 (2001), s. 101-110 ISSN 1058-4587 R&D Projects: GA MŠk LN00A015; GA ČR GA202/00/1425 Institutional research plan: CEZ:AV0Z1010914 Keywords : thin film * refraction index * polarization * film thickness Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.512, year: 2001

  16. Optically controlled polarizer using a ladder transition for high speed Stokesmetric Imaging and Quantum Zeno Effect based optical logic.

    Science.gov (United States)

    Krishnamurthy, Subramanian; Wang, Y; Tu, Y; Tseng, S; Shahriar, M S

    2013-10-21

    We demonstrate an optically controlled polarizer at ~1323 nm using a ladder transition in a Rb vapor cell. The lower leg of the 5S(1/2),F = 1->5P(1/2),F = 1,2->6S(1/2),F = 1,2 transitions is excited by a Ti:Sapphire laser locked to a saturated absorption signal, representing the control beam. A tunable fiber laser at ~1323 nm is used to excite the upper leg of the transitions, representing the signal beam. When the control beam is linearly polarized, it produces an excitation of the intermediate level with a particular orientation of the angular momentum. Under ideal conditions, this orientation is transparent to the signal beam if it has the same polarization as the control beam and is absorbed when it is polarized orthogonally. We also present numerical simulations of the system using a comprehensive model which incorporates all the relevant Zeeman sub-levels in the system, and identify means to improve the performance of the polarizer. A novel algorithm to compute the evolution of large scale quantum system enabled us to perform this computation, which may have been considered too cumbersome to carry out previously. We describe how such a polarizer may serve as a key component for high-speed Stokesmetric imaging. We also show how such a polarizer, combined with an optically controlled waveplate, recently demonstrated by us, can be used to realize a high speed optical logic gate by making use of the Quantum Zeno Effect. Finally, we describe how such a logic gate can be realized at an ultra-low power level using a tapered nanofiber embedded in a vapor cell.

  17. The production and extraction of polarized electrons from an optically pumped helium discharge

    International Nuclear Information System (INIS)

    Vandiver, R.J.; Schearer, L.D.; Gay, T.J.

    1992-01-01

    Polarized electrons are produced from interactions involving nearly 100% polarized helium 2 3 S 1 metastable atoms in a weak electrical discharge. The high metastable polarizations are obtained through the use of recently developed, high-power lasers tunable to the relevant helium transitions near 1083 nm and the development of a crossed beam pumping technique. The dominant interactions involving the 2 3 S 1 atoms and electrons are spin preserving; hence the electrons of the discharge attain a high polarization. The authors have extracted a well collimated electron beam with over 20 μA of current from the discharge. An optical polarimeter will be used to determine the polarization of the extracted electrons

  18. Operational experience with the TRIUMF optically pumped polarized H- ion source

    International Nuclear Information System (INIS)

    Schmor, P.W.; Buchmann, L.; Jayamanna, K.; Levy, C.D.P.; McDonald, M.; Ruegg, R.

    1991-05-01

    The initial goal of a polarized proton beam extracted from the TRIUMF cyclotron, having a current of 5 μA with 60% polarization, has been achieved with the development of the optically pumped polarized H - ion source. This beam is now being used to produce an intense secondary beam of polarized neutrons for the TRIUMF experimental program. Much of the recent development effort has addressed the reliability requirements for routine operation. This paper describes the results with emphasis on the laser stabilization subsystem, the modifications to the electron cyclotron resonance proton ion source (ECRIS), the sodium charge exchange cells and the development of a low energy polarimeter. Also discussed are the developments which should lead to a higher polarization. (Author) 7 refs

  19. Dynamical model of coherent circularly polarized optical pulse interactions with two-level quantum systems

    International Nuclear Information System (INIS)

    Slavcheva, G.; Hess, O.

    2005-01-01

    We propose and develop a method for theoretical description of circularly (elliptically) polarized optical pulse resonant coherent interactions with two-level atoms. The method is based on the time-evolution equations of a two-level quantum system in the presence of a time-dependent dipole perturbation for electric dipole transitions between states with total angular-momentum projection difference (ΔJ z =±1) excited by a circularly polarized electromagnetic field [Feynman et al., J. Appl. Phys. 28, 49 (1957)]. The adopted real-vector representation approach allows for coupling with the vectorial Maxwell's equations for the optical wave propagation and thus the resulting Maxwell pseudospin equations can be numerically solved in the time domain without any approximations. The model permits a more exact study of the ultrafast coherent pulse propagation effects taking into account the vector nature of the electromagnetic field and hence the polarization state of the optical excitation. We demonstrate self-induced transparency effects and formation of polarized solitons. The model represents a qualitative extension of the well-known optical Maxwell-Bloch equations valid for linearly polarized light and a tool for studying coherent quantum control mechanisms

  20. Optical polarization position angle versus radio structure axis in Seyfert galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Antonucci, R R.J. [National Radio Astronomy Observatory, Charlottesville, VA (USA)

    1983-05-12

    The hypothesis that there are two polarization classes of Seyfert galaxies, analogous to the perpendicular and parallel radio galaxy groups, is investigated by examining optical polarimetry data. In the sample considered it is shown that all the Seyfert 1 galaxies have roughly parallel polarization while all the Seyfert 2 galaxies have roughly perpendicular polarizations. These alignment effects can be interpreted as being due to thin and thick scattering disks, respectively, surrounding the continuum sources. This would represent a fundamental difference between the two types of Seyfert galaxies.

  1. Estimation of polarization distribution on gold nanorods system from hierarchical features of optical near-field

    Science.gov (United States)

    Uchiyama, Kazuharu; Nishikawa, Naoki; Nakagomi, Ryo; Kobayashi, Kiyoshi; Hori, Hirokazu

    2018-02-01

    To design optoelectronic functionalities in nanometer scale based on interactions of electronic system with optical near-fields, it is essential to evaluate the relationship between optical near-fields and their sources. Several theoretical studies have been performed, so far, to analyze such complex relationship to design the interaction fields of several specific scales. In this study, we have performed detailed and high-precision measurements of optical near-field structures woven by a large number of independent polarizations generated in the gold nanorods array under laser light irradiation at the resonant frequency. We have accumulated the multi-layered data of optical near-field imaging at different heights above the planar surface with the resolution of several nm by a STM-assisted scanning near-field optical microscope. Based on these data, we have performed an inverse calculation to estimate the position, direction, and strength of the local polarization buried under the flat surface of the sample. As a result of the inverse operation, we have confirmed that the complexities in the nanometer scale optical near-fields could be reconstructed by combinations of induced polarization in each gold nanorod. We have demonstrated the hierarchical properties of optical near-fields based on spatial frequency expansion and superposition of dipole fields to provide insightful information for applications such for secure multi-layered information storage.

  2. Polarizing Beam Splitter: A New Approach Based on Transformation Optics

    Science.gov (United States)

    Mueller, Jonhatan; Wegener, Martin

    Standard optical elements (e.g. lenses, prisms) are mostly designed of piecewise homogeneous and isotropic dielectrics. However, in theory one has far more possibilities to influence electromagnetic waves, namely all the components of the permittivity and permeability tensors. In the past few years, on the one hand, new micro fabrication methods allowed for new freedom in controlling of the optical parameters using so called artificial metamaterials. On the other hand, the theory of transformation optics has given a somewhat intuitive approach for the design of such structures. The most popular feature of this kind is certainly optical cloaking (i.e. [1,2]). However, the full capabilities of other transformation optical devices are far from being fully explored. In my work, I focused on pure dielectric structures in a non-resonant and therefore non-lossy regime. Although the relative permittivity one can achieve this way is limited by the available natural dielectrics, a broad spectrum of features can be realized.

  3. Holographic non-Gaussianity

    International Nuclear Information System (INIS)

    McFadden, Paul; Skenderis, Kostas

    2011-01-01

    We investigate the non-Gaussianity of primordial cosmological perturbations within our recently proposed holographic description of inflationary universes. We derive a holographic formula that determines the bispectrum of cosmological curvature perturbations in terms of correlation functions of a holographically dual three-dimensional non-gravitational quantum field theory (QFT). This allows us to compute the primordial bispectrum for a universe which started in a non-geometric holographic phase, using perturbative QFT calculations. Strikingly, for a class of models specified by a three-dimensional super-renormalisable QFT, the primordial bispectrum is of exactly the factorisable equilateral form with f NL equil. = 5/36, irrespective of the details of the dual QFT. A by-product of this investigation is a holographic formula for the three-point function of the trace of the stress-energy tensor along general holographic RG flows, which should have applications outside the remit of this work

  4. Continuous wave protocol for simultaneous polarization and optical detection of P1-center electron spin resonance

    Science.gov (United States)

    Kamp, E. J.; Carvajal, B.; Samarth, N.

    2018-01-01

    The ready optical detection and manipulation of bright nitrogen vacancy center spins in diamond plays a key role in contemporary quantum information science and quantum metrology. Other optically dark defects such as substitutional nitrogen atoms (`P1 centers') could also become potentially useful in this context if they could be as easily optically detected and manipulated. We develop a relatively straightforward continuous wave protocol that takes advantage of the dipolar coupling between nitrogen vacancy and P1 centers in type 1b diamond to detect and polarize the dark P1 spins. By combining mutual spin flip transitions with radio frequency driving, we demonstrate the simultaneous optical polarization and detection of the electron spin resonance of the P1 center. This technique should be applicable to detecting and manipulating a broad range of dark spin populations that couple to the nitrogen vacancy center via dipolar fields, allowing for quantum metrology using these spin populations.

  5. Holographic Optical Element-Based Laser Diode Source System for Direct Metal Deposition in Space, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — To meet the challenges of rapid prototyping, direct hardware fabrication, and on-the-spot repairs on the ground and on NASA space platforms, Physical Optics...

  6. Polarization-dependent tunneling of light in gradient optics

    Czech Academy of Sciences Publication Activity Database

    Shvartsburg, A. B.; Kuzmiak, Vladimír; Petite, G.

    2007-01-01

    Roč. 76, č. 1 (2007), 016603.1-01663.11 ISSN 1539-3755 R&D Projects: GA MŠk(CZ) OC P11.001 Institutional research plan: CEZ:AV0Z20670512 Keywords : wave propagation * tunnelling Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.483, year: 2007

  7. Nonlinear Fourier transform for dual-polarization optical communication system

    DEFF Research Database (Denmark)

    Gaiarin, Simone

    communication is considered an emerging paradigm in fiber-optic communications that could potentially overcome these limitations. It relies on a mathematical technique called “inverse scattering transform” or “nonlinear Fourier transform (NFT)” to exploit the “hidden” linearity of the nonlinear Schrödinger...

  8. Exploring Neural Cell Dynamics with Digital Holographic Microscopy

    KAUST Repository

    Marquet, Pierre; Jourdain, Pascal; Boss, Daniel; Depeursinge, Christian D.; Magistretti, Pierre J.

    2013-01-01

    In this talk, I will present how digital holographic microscopy, as a powerful quantitative phase technique, can non-invasively measure cell dynamics and especially resolve local neuronal network activity through simultaneous multiple site optical recording.

  9. Exploring Neural Cell Dynamics with Digital Holographic Microscopy

    KAUST Repository

    Marquet, Pierre

    2013-04-21

    In this talk, I will present how digital holographic microscopy, as a powerful quantitative phase technique, can non-invasively measure cell dynamics and especially resolve local neuronal network activity through simultaneous multiple site optical recording.

  10. Snapshot polarization-sensitive plug-in optical module for a Fourier-domain optical coherence tomography system

    Science.gov (United States)

    Marques, Manuel J.; Rivet, Sylvain; Bradu, Adrian; Podoleanu, Adrian

    2018-02-01

    In this communication, we present a proof-of-concept polarization-sensitive Optical Coherence Tomography (PS-OCT) which can be used to characterize the retardance and the axis orientation of a linear birefringent sample. This module configuration is an improvement from our previous work1, 2 since it encodes the two polarization channels on the optical path difference, effectively carrying out the polarization measurements simultaneously (snapshot measurement), whilst retaining all the advantages (namely the insensitivity to environmental parameters when using SM fibers) of these two previous configurations. Further progress consists in employing Master Slave OCT technology,3 which is used to automatically compensate for the dispersion mismatch introduced by the elements in the module. This is essential given the encoding of the polarization states on two different optical path lengths, each of them having dissimilar dispersive properties. By utilizing this method instead of the commonly used re-linearization and numerical dispersion compensation methods an improvement in terms of the calculation time required can be achieved.

  11. A Transflective Nano-Wire Grid Polarizer Based Fiber-Optic Sensor

    Directory of Open Access Journals (Sweden)

    Yan-Qing Lu

    2011-02-01

    Full Text Available A transflective nano-wire grid polarizer is fabricated on a single mode fiber tip by focused ion beam machining. In contrast to conventional absorptive in-line polarizers, the wire grids reflect TE-mode, while transmitting TM-mode light so that no light power is discarded. A reflection contrast of 13.7 dB and a transmission contrast of 4.9 dB are achieved in the 1,550 nm telecom band using a 200-nm wire grid fiber polarizer. With the help of an optic circulator, the polarization states of both the transmissive and reflective lights in the fiber may be monitored simultaneously. A kind of robust fiber optic sensor is thus proposed that could withstand light power variations. To verify the idea, a fiber pressure sensor with the sensitivity of 0.24 rad/N is demonstrated. The corresponding stress-optic coefficient of the fiber is measured. In addition to pressure sensing, this technology could be applied in detecting any polarization state change induced by magnetic fields, electric currents and so on.

  12. Effect of atomic noise on optical squeezing via polarization self-rotation in a thermal vapor cell

    DEFF Research Database (Denmark)

    Hsu, M.T.L.; Hetet, G.; Peng, A.

    2006-01-01

    The traversal of an elliptically polarized optical field through a thermal vapor cell can give rise to a rotation of its polarization axis. This process, known as polarization self-rotation (PSR), has been suggested as a mechanism for producing squeezed light at atomic transition wavelengths. We ...

  13. A comparative study with a 755 nm picosecond Alexandrite laser with a diffractive lens array and a 532 nm/1064 nm Nd:YAG with a holographic optic.

    Science.gov (United States)

    Tanghetti Md, Emil; Jennings, John

    2018-01-01

    This study was performed to better understand the cutaneous effects of using a fractional picosecond laser at 755 nm with a diffractive lens array and a picosecond Nd:YAG laser at 532 mn and 1064 nm with a holographic optic. We characterized the injuries created by these devices on skin clinically and histologically over 24 hours. With this information we modeled the effects of these devices on a cutaneous target. Eight patients, representing Fitzpatrick skin types I-VI, were treated on their backs with a picosecond Alexandrite laser with a diffractive lens array, as well as a picosecond Nd:YAG laser at 532 nm and 1064 nm with a holographic optic. Photographs were taken 15 minutes and 24 hours after treatments. Punch biopsies were obtained at 24 hours and examined histologically. Treatment with the picosecond Nd:YAG laser at both 532 nm and 1064 nm with the holographic optic revealed erythema and small scatted areas of petechial hemorrhage areas immediately and in many cases at 24 hours after treatment. The 755 nm picosecond Alexandrite laser with diffractive lens array produced erythema immediately after treatment, which largely dissipated 24 hours later. Histologies revealed intra-epidermal vacuoles with all three wavelengths. Fractional picosecond Nd:YAG laser at 532 nm and 1064 nm with the holographic optic showed focal areas of dermal and intra-epidermal hemorrhage with areas of vascular damage in some patients. This study demonstrates that both fractional picosecond devices produce vacuoles in the skin, which are most likely due to areas of laser induced optical breakdown (LIOB). In the patients (skin type II-IV) we observed scatter areas of hemorrhage in the skin, due to vascular damage with the 532 nm and 1064 nm, but not with 755 nm wavelengths. Lasers Surg. Med. 50:37-44, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Resonance-inclined optical nuclear spin polarization of liquids in diamond structures

    Science.gov (United States)

    Chen, Q.; Schwarz, I.; Jelezko, F.; Retzker, A.; Plenio, M. B.

    2016-02-01

    Dynamic nuclear polarization (DNP) of molecules in a solution at room temperature has the potential to revolutionize nuclear magnetic resonance spectroscopy and imaging. The prevalent methods for achieving DNP in solutions are typically most effective in the regime of small interaction correlation times between the electron and nuclear spins, limiting the size of accessible molecules. To solve this limitation, we design a mechanism for DNP in the liquid phase that is applicable for large interaction correlation times. Importantly, while this mechanism makes use of a resonance condition similar to solid-state DNP, the polarization transfer is robust to a relatively large detuning from the resonance due to molecular motion. We combine this scheme with optically polarized nitrogen-vacancy (NV) center spins in nanodiamonds to design a setup that employs optical pumping and is therefore not limited by room temperature electron thermal polarization. We illustrate numerically the effectiveness of the model in a flow cell containing nanodiamonds immobilized in a hydrogel, polarizing flowing water molecules 4700-fold above thermal polarization in a magnetic field of 0.35 T, in volumes detectable by current NMR scanners.

  15. Precision polarization measurements of atoms in a far-off-resonance optical dipole trap

    International Nuclear Information System (INIS)

    Fang, F.; Vieira, D. J.; Zhao, X.

    2011-01-01

    Precision measurement of atomic and nuclear polarization is an essential step for beta-asymmetry measurement of radioactive atoms. In this paper, we report the polarization measurement of Rb atoms in an yttrium-aluminum-garnet (YAG) far-off-resonance optical dipole trap. We have prepared a cold cloud of polarized Rb atoms in the YAG dipole trap by optical pumping and achieved an initial nuclear polarization of up to 97.2(5)%. The initial atom distribution in different Zeeman levels is measured by using a combination of microwave excitation, laser pushing, and atomic retrap techniques. The nuclear-spin polarization is further purified to 99.2(2)% in 10 s and maintained above 99% because the two-body collision loss rate between atoms in mixed spin states is greater than the one-body trap loss rate. Systematic effects on the nuclear polarization, including the off-resonance Raman scattering, magnetic field gradient, and background gas collisions, are discussed.

  16. Polarization-insensitive optical gain characteristics of highly stacked InAs/GaAs quantum dots

    International Nuclear Information System (INIS)

    Kita, Takashi; Suwa, Masaya; Kaizu, Toshiyuki; Harada, Yukihiro

    2014-01-01

    The polarized optical gain characteristics of highly stacked InAs/GaAs quantum dots (QDs) with a thin spacer layer fabricated on an n + -GaAs (001) substrate were studied in the sub-threshold gain region. Using a 4.0-nm-thick spacer layer, we realized an electronically coupled QD superlattice structure along the stacking direction, which enabled the enhancement of the optical gain of the [001] transverse-magnetic (TM) polarization component. We systematically studied the polarized electroluminescence properties of laser devices containing 30 and 40 stacked InAs/GaAs QDs. The net modal gain was analyzed using the Hakki-Paoli method. Owing to the in-plane shape anisotropy of QDs, the polarization sensitivity of the gain depends on the waveguide direction. The gain showing polarization isotropy between the TM and transverse-electric polarization components is high for the [110] waveguide structure, which occurs for higher amounts of stacked QDs. Conversely, the isotropy of the [−110] waveguide is easily achieved even if the stacking is relatively low, although the gain is small.

  17. Implementation of all-optical reversible logic gate based on holographic laser induced grating using azo-dye doped polymers

    Science.gov (United States)

    Forsati, Rana; Valipour Ebrahimi, Sara; Navi, Keivan; Mohajerani, Ezeddin; Jashnsaz, Hossein

    2013-02-01

    Increasing demand for power reduction in computer systems has led to new trends in computations and computer design including reversible computing. Its main aim is to eliminate power dissipation in logical elements but can have some other advantages such as data security and error prevention. Because of interesting properties of reversible computing, implementing computing devices with reversible manner is the only way to make the reversible computing a reality. In recent years, reversible logic has turned out to be a promising computing paradigm having application in CMOS, nanotechnology, quantum computing and optical computing. In this paper, we propose and realize a novel implementation of Toffoli gate in all-optical domain. We have explained its principle of operations and described an actual experimental implementation. The all-optical reversible gate presented in this paper will be useful in different applications such as arithmetic and logical operations in the domain of reversible logic-based computing.

  18. Impact of optical feedback on current-induced polarization behavior of 1550 nm vertical-cavity surface-emitting lasers.

    Science.gov (United States)

    Deng, Tao; Wu, Zheng-Mao; Xie, Yi-Yuan; Wu, Jia-Gui; Tang, Xi; Fan, Li; Panajotov, Krassimir; Xia, Guang-Qiong

    2013-06-01

    Polarization switching (PS) between two orthogonal linearly polarized fundamental modes is experimentally observed in commercial free-running 1550 nm vertical-cavity surface-emitting lasers (VCSELs) (Raycan). The characteristics of this PS are strongly modified after introducing a polarization-preserved (PP) or polarization-orthogonal (PO) optical feedback. Under the case that the external cavity is approximately 30 cm, the PP optical feedback results in the PS point shifting toward a lower injection current, and the region within which the two polarization modes coexist is enlarged with the increase of the PP feedback strength. Under too-strong PP feedback levels, the PS disappears. The impact of PO optical feedback on VCSEL polarization behavior is quite similar to that of PP optical feedback, but larger feedback strength is needed to obtain similar results.

  19. Optically initialized robust valley-polarized holes in monolayer WSe2

    KAUST Repository

    Hsu, Wei-Ting; Chen, Yen-Lun; Chen, Chiang-Hsiao; Liu, Pang-Shiuan; Hou, Tuo-Hung; Li, Lain-Jong; Chang, Wen-Hao

    2015-01-01

    a unique platform to develop such valleytronic devices, the anticipated long-lived valley pseudospin has not been observed yet. Here we demonstrate that robust valley-polarized holes in monolayer WSe2 can be initialized by optical pumping. Using time

  20. Optical reconfiguration and polarization control in semi-continuous gold films close to the percolation threshold

    DEFF Research Database (Denmark)

    Frydendahl, Christian; Repän, Taavi; Geisler, Mathias

    2017-01-01

    permanent morphological changes with a femtosecond (fs)-pulsed laser above a critical power. Optical transmission spectroscopy measurements show a correlation between the spectra of the morphologically modified films and the wavelength, polarization, and the intensity of the laser used for alteration...

  1. Parametric imaging of collagen structural changes in human osteoarthritic cartilage using optical polarization tractography

    Science.gov (United States)

    Ravanfar, Mohammadreza; Pfeiffer, Ferris M.; Bozynski, Chantelle C.; Wang, Yuanbo; Yao, Gang

    2017-12-01

    Collagen degeneration is an important pathological feature of osteoarthritis. The purpose of this study is to investigate whether the polarization-sensitive optical coherence tomography (PSOCT)-based optical polarization tractography (OPT) can be useful in imaging collagen structural changes in human osteoarthritic cartilage samples. OPT eliminated the banding artifacts in conventional PSOCT by calculating the depth-resolved local birefringence and fiber orientation. A close comparison between OPT and PSOCT showed that OPT provided improved visualization and characterization of the zonal structure in human cartilage. Experimental results obtained in this study also underlined the importance of knowing the collagen fiber orientation in conventional polarized light microscopy assessment. In addition, parametric OPT imaging was achieved by quantifying the surface roughness, birefringence, and fiber dispersion in the superficial zone of the cartilage. These quantitative parametric images provided complementary information on the structural changes in cartilage, which can be useful for a comprehensive evaluation of collagen damage in osteoarthritic cartilage.

  2. NONINVASIVE DIAGNOSIS OF URINARY BLADDER CANCER BY CROSS-POLARIZATION OPTICAL COHERENCE TOMOGRAPHY: CLINICAL RESULTS

    Directory of Open Access Journals (Sweden)

    O. S. Streltsova

    2014-07-01

    Full Text Available The investigation examined the feasibility of cross-polarization optical cohe-rence tomography (CP OCT to detect early urinary bladder cancer (UBC. Studies were performed in 376 patients; 5290 images were obtained using an OCT 133-U optical coherence tomograph. To acquire and compare intrared-light scattering images in baseline and orthogonal polarizations is the basis of CP OCT; their analysis makes it possible to judge from the state of the epithelium/connective tissue system and to obtain information on changes in tissue depolarizing components, collagen in particular. The authors elaborated criteria as determinants of the nature of CP OCT changes in direct and orthogonal polarizations in health, inflammatory changes, and UBC at its early stage - urothelial dysplasia and carcinoma in situ in flat suspected areas.

  3. Circularly polarized infrared and visible sum-frequency-generation spectroscopy: Vibrational optical activity measurement

    International Nuclear Information System (INIS)

    Cheon, Sangheon; Cho, Minhaeng

    2005-01-01

    Vibrational optical activity spectroscopies utilizing either circularly polarized ir or circularly polarized visible beams were theoretically investigated by considering the infrared and visible sum-frequency-generation (IV-SFG) schemes. In addition to the purely electric dipole-allowed chiral component of the IV-SFG susceptibility, the polarizability-electric quadrupole hyperpolarizability term also contributes to the vibrationally resonant IV-SFG susceptibility. The circular-intensity-difference signal is shown to be determined by the interferences between the all-electric dipole-allowed chiral component and the polarizability-electric-dipole or electric-dipole-electric-quadrupole Raman optical activity tensor components. The circularly polarized SFG methods are shown to be potentially useful coherent spectroscopic tools for determining absolute configurations of chiral molecules in condensed phases

  4. Tests of a polarized source of hydrogen and deuterium based on spin-exchange optical pumping and a storage cell for polarized deuterium

    International Nuclear Information System (INIS)

    Holt, R.J.; Gilman, R.; Kinney, E.R.

    1988-01-01

    A novel laser-driven polarized source of hydrogen and deuterium which is based on the principle of spin-exchange optical pumping has been developed at Argonne. The advantages of this method over conventional polarized sources for internal target experiments is discussed. At present, the laser-driven polarized source delivers hydrogen 8 x 10 16 atoms/s with a polarization of 24% and deuterium at 6 x 10 16 atoms/s with a polarization of 25%. A passive storage cell for polarized deuterium was tested in the VEPP-3 electron storage ring. The storage cell was found to increase the target thickness by approximately a factor of three and no loss in polarization was observed. 10 refs., 4 figs., 2 tabs

  5. Optical modeling and polarization calibration for CMB measurements with ACTPol and Advanced ACTPol

    Science.gov (United States)

    Koopman, Brian; Austermann, Jason; Cho, Hsiao-Mei; Coughlin, Kevin P.; Duff, Shannon M.; Gallardo, Patricio A.; Hasselfield, Matthew; Henderson, Shawn W.; Ho, Shuay-Pwu Patty; Hubmayr, Johannes; Irwin, Kent D.; Li, Dale; McMahon, Jeff; Nati, Federico; Niemack, Michael D.; Newburgh, Laura; Page, Lyman A.; Salatino, Maria; Schillaci, Alessandro; Schmitt, Benjamin L.; Simon, Sara M.; Vavagiakis, Eve M.; Ward, Jonathan T.; Wollack, Edward J.

    2016-07-01

    The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive upgrade to the Atacama Cosmology Telescope, located at an elevation of 5190 m on Cerro Toco in Chile. ACTPol uses transition edge sensor bolometers coupled to orthomode transducers to measure both the temperature and polarization of the Cosmic Microwave Background (CMB). Calibration of the detector angles is a critical step in producing polarization maps of the CMB. Polarization angle offsets in the detector calibration can cause leakage in polarization from E to B modes and induce a spurious signal in the EB and TB cross correlations, which eliminates our ability to measure potential cosmological sources of EB and TB signals, such as cosmic birefringence. We calibrate the ACTPol detector angles by ray tracing the designed detector angle through the entire optical chain to determine the projection of each detector angle on the sky. The distribution of calibrated detector polarization angles are consistent with a global offset angle from zero when compared to the EB-nulling offset angle, the angle required to null the EB cross-correlation power spectrum. We present the optical modeling process. The detector angles can be cross checked through observations of known polarized sources, whether this be a galactic source or a laboratory reference standard. To cross check the ACTPol detector angles, we use a thin film polarization grid placed in front of the receiver of the telescope, between the receiver and the secondary reflector. Making use of a rapidly rotating half-wave plate (HWP) mount we spin the polarizing grid at a constant speed, polarizing and rotating the incoming atmospheric signal. The resulting sinusoidal signal is used to determine the detector angles. The optical modeling calibration was shown to be consistent with a global offset angle of zero when compared to EB nulling in the first ACTPol results and will continue to be a part of our calibration implementation. The first

  6. DeVelopment of the high-intensity polarized H- source with proton charge exchange on sodium optically oriented atoms

    International Nuclear Information System (INIS)

    Zelenskij, A.N.; Kokhanovskij, S.A.

    1982-01-01

    The results of experimental study on the source of polarized H - ions at polarized electron capture by proton from optically oriented sodium atoms are presented. Circular-polarized dye laser radiation with lamp pumping is used for polarization of highly dense sodium vapors in the pulsed mode. A facility for polarization measurement in the ion source is described. Dependence of the counting rate of metastables for the right and left circular radiation polarization in respect to wave length is presented. The results of measuring the degree of polarization under change of sodium density are revealed. The measurements have disclosed that obtaining of high polarization degree at 20-30% charge exchange effectiveness is possible but large radiation power is required. Use of a dense charge exchange target provides high effectiveness of hte whole polarization process. Yield of polarized H - ions can approach 10 μA/1 mA of the initial proton current

  7. The collagen structure of equine articular cartilage, characterized using polarization-sensitive optical coherence tomography

    International Nuclear Information System (INIS)

    Ugryumova, Nadya; Attenburrow, Don P; Winlove, C Peter; Matcher, Stephen J

    2005-01-01

    Optical coherence tomography and polarization-sensitive optical coherence tomography images of equine articular cartilage are presented. Measurements were made on intact joint surfaces. Significant (e.g. x 2) variations in the intrinsic birefringence were found over spatial scales of a few millimetres, even on samples taken from young (18 month) animals that appeared visually homogeneous. A comparison of data obtained on a control tissue (equine flexor tendon) further suggests that significant variations in the orientation of the collagen fibres relative to the plane of the joint surface exist. Images of visually damaged cartilage tissue show characteristic features both in terms of the distribution of optical scatterers and of the birefringent components

  8. The collagen structure of equine articular cartilage, characterized using polarization-sensitive optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ugryumova, Nadya; Attenburrow, Don P; Winlove, C Peter; Matcher, Stephen J [Biomedical Physics Group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom)

    2005-08-07

    Optical coherence tomography and polarization-sensitive optical coherence tomography images of equine articular cartilage are presented. Measurements were made on intact joint surfaces. Significant (e.g. x 2) variations in the intrinsic birefringence were found over spatial scales of a few millimetres, even on samples taken from young (18 month) animals that appeared visually homogeneous. A comparison of data obtained on a control tissue (equine flexor tendon) further suggests that significant variations in the orientation of the collagen fibres relative to the plane of the joint surface exist. Images of visually damaged cartilage tissue show characteristic features both in terms of the distribution of optical scatterers and of the birefringent components.

  9. Optically polarized atoms understanding light-atom interactions

    CERN Document Server

    Auzinsh, Marcis; Rochester, Simon M

    2010-01-01

    This book is addressed at upper-level undergraduate and graduate students involved in research in atomic, molecular, and optical Physics. It will also be useful to researchers practising in this field. It gives an intuitive, yet sufficiently detailed and rigorous introduction to light-atom interactions with a particular emphasis on the symmetry aspects of the interaction, especially those associated with the angular momentum of atoms and light. The book will enable readers to carryout practical calculations on their own, and is richly illustrated with examples drawn from current research topic

  10. Collapse dynamics of a vector vortex optical field with inhomogeneous states of polarization

    International Nuclear Information System (INIS)

    Chen, Rui-Pin; Zhao, Ting-Yu; Zhang, Xiaobo; Zhong, Li-Xin; Chew, Khian-Hooi

    2015-01-01

    Based on a pair of coupled 2D nonlinear Schrödinger equations, the collapse dynamics of a vector field with hybrid states of polarization (SoP) in a Kerr medium is demonstrated. The critical power for an optical field to collapse is present, and the full vectorial numerical simulations provide detailed information about the evolution and partial collapse of the vector field in a Kerr medium. Our results reveal that the optical field prefers to collapse in linearly-polarization, as a result of the self-focusing effect difference in linearly, elliptically and circularly polarized components. The SoP in the field cross-section changes and propagates with a spiral trajectory when the vector beams are imposed with a vortex. The vectorial effect on the collapse of a vector optical field can prevail over the noise even though it reaches 10% amplitude of the optical field. The unique feature of these structured collapses of a vector optical field may lead to new phenomena in the interaction of light with matter. (paper)

  11. Holographic Moire Contouring

    Science.gov (United States)

    Sciammarella, C. A.; Sainov, Ventseslav; Simova, Eli

    1990-04-01

    Theoretical analysis and experimental results on holographic moire contouring (HMC) of difussely reflecting objects are presented. The sensitivity and application constraints of the method are discussed. A high signal-to-noise ratio and contrast of the fringes is achieved through the use of high quality silver halide holographic plates HP-650. A good agreement between theoretical and experimental results is observed.

  12. Symmetry evaluation for an interferometric fiber optic gyro coil utilizing a bidirectional distributed polarization measurement system.

    Science.gov (United States)

    Peng, Feng; Li, Chuang; Yang, Jun; Hou, Chengcheng; Zhang, Haoliang; Yu, Zhangjun; Yuan, Yonggui; Li, Hanyang; Yuan, Libo

    2017-07-10

    We propose a dual-channel measurement system for evaluating the optical path symmetry of an interferometric fiber optic gyro (IFOG) coil. Utilizing a bidirectional distributed polarization measurement system, the forward and backward transmission performances of an IFOG coil are characterized simultaneously by just a one-time measurement. The simple but practical configuration is composed of a bidirectional Mach-Zehnder interferometer and multichannel transmission devices connected to the IFOG coil under test. The static and dynamic temperature results of the IFOG coil reveal that its polarization-related symmetric properties can be effectively obtained with high accuracy. The optical path symmetry investigation is highly beneficial in monitoring and improving the winding technology of an IFOG coil and reducing the nonreciprocal effect of an IFOG.

  13. Integrated-optics heralded controlled-NOT gate for polarization-encoded qubits

    Science.gov (United States)

    Zeuner, Jonas; Sharma, Aditya N.; Tillmann, Max; Heilmann, René; Gräfe, Markus; Moqanaki, Amir; Szameit, Alexander; Walther, Philip

    2018-03-01

    Recent progress in integrated-optics technology has made photonics a promising platform for quantum networks and quantum computation protocols. Integrated optical circuits are characterized by small device footprints and unrivalled intrinsic interferometric stability. Here, we take advantage of femtosecond-laser-written waveguides' ability to process polarization-encoded qubits and present an implementation of a heralded controlled-NOT gate on chip. We evaluate the gate performance in the computational basis and a superposition basis, showing that the gate can create polarization entanglement between two photons. Transmission through the integrated device is optimized using thermally expanded core fibers and adiabatically reduced mode-field diameters at the waveguide facets. This demonstration underlines the feasibility of integrated quantum gates for all-optical quantum networks and quantum repeaters.

  14. Conversion from non-orthogonally to orthogonally polarized optical single-sideband modulation using optically injected semiconductor lasers.

    Science.gov (United States)

    Hung, Yu-Han; Tseng, Chin-Hao; Hwang, Sheng-Kwang

    2018-06-01

    This Letter investigates an optically injected semiconductor laser for conversion from non-orthogonally to orthogonally polarized optical single-sideband modulation. The underlying mechanism relies solely on nonlinear laser characteristics and, thus, only a typical semiconductor laser is required as the key conversion unit. This conversion can be achieved for a broadly tunable frequency range up to at least 65 GHz. After conversion, the microwave phase quality, including linewidth and phase noise, is mostly preserved, and simultaneous microwave amplification up to 23 dB is feasible.

  15. Nonlinear Optical Response of Polar Semiconductors in the Terahertz Range

    Science.gov (United States)

    Roman, Eric; Yates, Jonathan; Veithen, Marek; Vanderbilt, David; Souza, Ivo

    2006-03-01

    Using the Berry-phase finite-field method, we compute from first-principles the recently measured infrared (IR) dispersion of the nonlinear susceptibility (2)circ in III-V zincblende semiconductors. At far-IR (terahertz) frequencies, in addition to the purely electronic response (2)circ∞, the total (2)circ depends on three other parameters, C1, C2, and C3, describing the contributions from ionic motion. They relate to the TO Raman polarizability and the second-order displacement-induced dielectric polarization and forces, respectively. Contrary to a widely-accepted model, but in agreement with the recent experiments on GaAs, ^1 we find that the contribution from mechanical anharmonicity dominates over electrical anharmonicity. By using Richardson extrapolation to evaluate the Berry's phase in k-space by finite differences, we are able to improve the convergence of the nonlinear susceptibility from the usual O[(δk)^2] to O[(δk)^4], dramatically reducing the computational cost. T. Dekorsy, V. A. Yakovlev, W. Seidel, M. Helm, and F. Keilmann, Phys. Rev. Lett. 90, 055508 (2003). C. Flytzanis, Phys. Rev. B 6, 1264 (1972). R. Umari and A. Pasquarello, Phys. Rev. B 68, 085114 (2003).

  16. Design, construction and testing of holographic PV concentrator modules and construction of a pilot plant for serial production of the holographic optical concentrator system on flexible foils. Follow-up project: Completion of the production process for mass production of large format holographic optical elements on flexible foils for solar technology. Final report; Auslegung, Konstruktion und Test von holographischen PV-Konzentratormodulen und Aufbau einer Pilotanlage zur Serienfertigung der holographischen Konzentratoroptik auf flexiblen Folien. Anschlussvorhaben: Vervollstaendigung der Produktionsverfahren fuer die Serienfertigung von grossformatigen holographischen optischen Elementen auf flexiblen Folien fuer die Solartechnik. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Stojanoff, C.G.; Froehlich, K.; Froening, P.; Schulat, J.; Schuette, H.; Wagemann, E.U.

    1997-06-30

    The aim of the research project is the development of a technique for value for money mass-production of large area holographic focussers made of dichromate gelatine for photo-electrics. The holograms act simultaneously as spectrally dispersing and focussing optical elements, which focus the sunlight in discrete bands on the spectrally matched solar cells. The three marked characteristics of the holographic focussers are the diffraction efficiency, the spectral bandwidth and the central working wavelength. The optimum values of these parameters depend on the variation of the layer thickness and the index of refraction over the aperture of the hologram, and on the ability of the DCG layer to provide great modulation of the index of refraction. Mass-production of large format holographic lenses (transmission holograms) and mirrors (reflection holograms) demands precise coating of the supporting substrate (glass or PET foil) with dichromate gelatine. Mass-production of the holographic lenses requires a matrix hologram with 50% diffraction efficiency and is done with two copier plants developed in the project. (orig./AKF) [Deutsch] Ziel des Forschungsvorhabens ist die Entwicklung einer Technologie fuer die preiswerte serielle Herstellung von grossflaechigen holographischen Konzentratoren in Dichromatgelatine fuer die Photovoltaik. Die Hologramme wirken gleichzeitig als spektral dispergierende und fokussierende optische Elemente, die das Sonnenlicht in diskreten Baendern auf spektral angepasste Solarzellen konzentrieren. Die drei kennzeichnenden Charakteristiken der holographischen Konzentratoren sind die Beugungseffizienz, die spektrale Bandbreite und die zentrale Arbeitswellenlaenge. Die optimalen Werte dieser Parameter sind durch die Variation der Schichtdicke und des Brechnungsindexes ueber die Apertur des Hologramms, sowie durch die Faehigkeit der DCG-Schicht grosse Brechungsindexmodulation zu ermoeglichen, eindeutig bedingt. Die serielle Fertigung der

  17. Polychromatic holographic plasma diagnostics

    International Nuclear Information System (INIS)

    Zhiglinskij, A.G.; Morozov, A.O.

    1992-01-01

    Review of holographic interferometry properties is performed and advantages of this method by plasma diagnostics are indicated. Main results obtained by the method of holographic interferometry in studies of various-type plasmas are considered. Special attention is paid to multiwave plasma diagnostics, the necessity of which is related as a rule to multicomponent composition of plasma. The eight laser and gas-discharge sources and holographic schemes, which make it possible to realize plasma polychromatic and holographic interferometry, are considered. The advantages of the method are demonstrated by examples of polychromatic holographic diagnostics of arc discharge and discharge in a hollow cathode. Review of theoretical works determining the applicability area of resonance polychromatic interferometry is carried out

  18. Investigations of Polarization Dependent Loss in Polarization Modulated Analog Optical Links

    Science.gov (United States)

    2015-12-29

    performance analog optical links for military applications primarily rely on the most common link architecture employing intensity modulation with...axis as bisector of DD and Ss•) PP = fl i p ( rr, PPO] ; (• flip the P vector imaqe on the PA •) PPh a t = unit[PP ) ; PHI = ArcCos [ PPha t .unit...DD ) ); AA = ((Cos ( PHI / 2])𔃼 • t p (Sin [ PHI / 2 ])𔃼 ) PP • tpDDhat / 2 ; CC2 =- ( MM · AA . SS • (AA . I!M) (I!M. SS)) ; CC3 = AA . SS; ln

  19. Polarization modeling and predictions for DKIST part 3: focal ratio and thermal dependencies of spectral polarization fringes and optic retardance

    Science.gov (United States)

    Harrington, David M.; Sueoka, Stacey R.

    2018-01-01

    Data products from high spectral resolution astronomical polarimeters are often limited by fringes. Fringes can skew derived magnetic field properties from spectropolarimetric data. Fringe removal algorithms can also corrupt the data if the fringes and object signals are too similar. For some narrow-band imaging polarimeters, fringes change the calibration retarder properties and dominate the calibration errors. Systems-level engineering tools for polarimetric instrumentation require accurate predictions of fringe amplitudes, periods for transmission, diattenuation, and retardance. The relevant instabilities caused by environmental, thermal, and optical properties can be modeled and mitigation tools developed. We create spectral polarization fringe amplitude and temporal instability predictions by applying the Berreman calculus and simple interferometric calculations to optics in beams of varying F/ number. We then apply the formalism to superachromatic six-crystal retarders in converging beams under beam thermal loading in outdoor environmental conditions for two of the world's largest observatories: the 10-m Keck telescope and the Daniel K. Inouye Solar Telescope (DKIST). DKIST will produce a 300-W optical beam, which has imposed stringent requirements on the large diameter six-crystal retarders, dichroic beamsplitters, and internal optics. DKIST retarders are used in a converging beam with F/ ratios between 8 and 62. The fringe spectral periods, amplitudes, and thermal models of retarder behavior assisted DKIST optical designs and calibration plans with future application to many astronomical spectropolarimeters. The Low Resolution Imaging Spectrograph with polarimetry instrument at Keck also uses six-crystal retarders in a converging F / 13 beam in a Cassegrain focus exposed to summit environmental conditions providing observational verification of our predictions.

  20. A robust holographic autofocusing criterion based on edge sparsity: comparison of Gini index and Tamura coefficient for holographic autofocusing based on the edge sparsity of the complex optical wavefront

    Science.gov (United States)

    Tamamitsu, Miu; Zhang, Yibo; Wang, Hongda; Wu, Yichen; Ozcan, Aydogan

    2018-02-01

    The Sparsity of the Gradient (SoG) is a robust autofocusing criterion for holography, where the gradient modulus of the complex refocused hologram is calculated, on which a sparsity metric is applied. Here, we compare two different choices of sparsity metrics used in SoG, specifically, the Gini index (GI) and the Tamura coefficient (TC), for holographic autofocusing on dense/connected or sparse samples. We provide a theoretical analysis predicting that for uniformly distributed image data, TC and GI exhibit similar behavior, while for naturally sparse images containing few high-valued signal entries and many low-valued noisy background pixels, TC is more sensitive to distribution changes in the signal and more resistive to background noise. These predictions are also confirmed by experimental results using SoG-based holographic autofocusing on dense and connected samples (such as stained breast tissue sections) as well as highly sparse samples (such as isolated Giardia lamblia cysts). Through these experiments, we found that ToG and GoG offer almost identical autofocusing performance on dense and connected samples, whereas for naturally sparse samples, GoG should be calculated on a relatively small region of interest (ROI) closely surrounding the object, while ToG offers more flexibility in choosing a larger ROI containing more background pixels.

  1. SYSTEMATIC STUDY OF GAMMA-RAY-BRIGHT BLAZARS WITH OPTICAL POLARIZATION AND GAMMA-RAY VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Ryosuke; Fukazawa, Yasushi; Kanda, Yuka; Shiki, Kensei; Kawabata, Miho; Nakaoka, Tatsuya; Takaki, Katsutoshi; Takata, Koji; Ui, Takahiro [Department of Physical Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Nalewajko, Krzysztof; Madejski, Greg M. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford University, 2575 Sand Hill Road M/S 29, Menlo Park, CA 94025 (United States); Uemura, Makoto; Tanaka, Yasuyuki T.; Kawabata, Koji S.; Akitaya, Hiroshi; Ohsugi, Takashi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Schinzel, Frank K. [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Moritani, Yuki [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Sasada, Mahito [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Yamanaka, Masayuki, E-mail: itoh@hep01.hepl.hiroshima-u.ac.jp, E-mail: itoh@hp.phys.titech.ac.jp [Department of Physics, Faculty of Science and Engineering, Konan University, Okamoto, Kobe, Hyogo 658-8501 (Japan); and others

    2016-12-10

    Blazars are highly variable active galactic nuclei that emit radiation at all wavelengths from radio to gamma rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies, and it also varies dramatically. The polarization of blazars is of interest for understanding the origin, confinement, and propagation of jets. However, even though numerous measurements have been performed, the mechanisms behind jet creation, composition, and variability are still debated. We performed simultaneous gamma-ray and optical photopolarimetry observations of 45 blazars between 2008 July and 2014 December to investigate the mechanisms of variability and search for a basic relation between the several subclasses of blazars. We identify a correlation between the maximum degree of optical linear polarization and the gamma-ray luminosity or the ratio of gamma-ray to optical fluxes. Since the maximum polarization degree depends on the condition of the magnetic field (chaotic or ordered), this result implies a systematic difference in the intrinsic alignment of magnetic fields in parsec-scale relativistic jets between different types of blazars (flat-spectrum radio quasars vs. BL Lacs) and consequently between different types of radio galaxies (FR I versus FR II).

  2. Polarization encoded all-optical quaternary R-S flip-flop using binary latch

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath; Chakraborty, Ajoy Kumar

    2009-04-01

    The developments of different multi-valued logic (MVL) systems have received considerable interests in recent years all over the world. In electronics, efforts have already been made to incorporate multi-valued system in logic and arithmetic data processing. But, very little efforts have been given in realization of MVL with optics. In this paper we present novel designs of certain all-optical circuits that can be used for realizing multi-valued logic functions. Polarization encoded all-optical quaternary (4-valued) R-S flip-flop is proposed and described. Two key circuits (all-optical encoder/decoder and a binary latch) are designed first. They are used to realize quaternary flip-flop in all-optical domain. Here the different quaternary logical states are represented by different polarized state of light. Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switch can take an important role. Computer simulation result confirming described methods and conclusion are given in this paper.

  3. Polarization independent polymer waveguide tunable receivers incorporating a micro-optic circulator

    Science.gov (United States)

    Wu, Xiaoping; Park, Tae-Hyun; Park, Su-Hyun; Seo, Jun-Kyu; Oh, Min-Cheol

    2018-06-01

    In order to simplify the receiver configuration in a wavelength division multiplexed optical fiber network, compact wavelength tunable filters have long been expected to be used as channel selectors. Bragg reflector inherently has the most suitable reflection spectrum for filtering a single wavelength from the densely multiplexed wavelength signal. Polymer has high thermo-optic coefficient and good thermal insulation property compared to the other optical waveguide materials such as silicon and silica materials. This can be used to broadly tune the reflection spectrum of Bragg reflector using a simple micro-heater. In this work, a micro-optic circulator component and a polymeric Bragg reflector device are assembled to produce a small form factor tunable receiver. Compared to the integrated-optical versions, the micro-optics are based on well-developed manufacturing processes and can achieve competitive production yields. The device exhibits high reflectivity with a flat top passband, and a polarization dependence of 0.06 nm achieved by virtue of the low birefringence of LFR polymer, which make a significant contribution to the implementation of polarization independent tunable receiver. The wavelength tuning range of 40 nm is demonstrated by using a bottom located heater with a groove for heat isolation.

  4. Omnidirectional narrow optical filters for circularly polarized light in a nanocomposite structurally chiral medium.

    Science.gov (United States)

    Avendaño, Carlos G; Palomares, Laura O

    2018-04-20

    We consider the propagation of electromagnetic waves throughout a nanocomposite structurally chiral medium consisting of metallic nanoballs randomly dispersed in a structurally chiral material whose dielectric properties can be represented by a resonant effective uniaxial tensor. It is found that an omnidirectional narrow pass band and two omnidirectional narrow band gaps are created in the blue optical spectrum for right and left circularly polarized light, as well as narrow reflection bands for right circularly polarized light that can be controlled by varying the light incidence angle and the filling fraction of metallic inclusions.

  5. Expression of the degree of polarization based on the geometrical optics pBRDF model.

    Science.gov (United States)

    Wang, Kai; Zhu, Jingping; Liu, Hong; Du, Bingzheng

    2017-02-01

    An expression of the degree of polarization (DOP) based on the geometrical optics polarimetric bidirectional reflectance distribution function model is presented. In this expression, the DOP is related to the surface roughness and decreases at different reflection angles because diffuse reflection is taken into consideration. A shadowing/masking function introduced into the specular reflection expression makes the DOP values decrease as the angle of incidence or observation approaches grazing. Different kinds of materials were measured to validate the accuracy of this DOP expression. The measured results suggest that the errors of the DOP are reduced significantly, and the polarized reflection characteristics can be described more reasonably and accurately.

  6. Low-Entropy States of Neutral Atoms in Polarization-Synthesized Optical Lattices.

    Science.gov (United States)

    Robens, Carsten; Zopes, Jonathan; Alt, Wolfgang; Brakhane, Stefan; Meschede, Dieter; Alberti, Andrea

    2017-02-10

    We create low-entropy states of neutral atoms by utilizing a conceptually new optical-lattice technique that relies on a high-precision, high-bandwidth synthesis of light polarization. Polarization-synthesized optical lattices provide two fully controllable optical lattice potentials, each of them confining only atoms in either one of the two long-lived hyperfine states. By employing one lattice as the storage register and the other one as the shift register, we provide a proof of concept using four atoms that selected regions of the periodic potential can be filled with one particle per site. We expect that our results can be scaled up to thousands of atoms by employing an atom-sorting algorithm with logarithmic complexity, which is enabled by polarization-synthesized optical lattices. Vibrational entropy is subsequently removed by sideband cooling methods. Our results pave the way for a bottom-up approach to creating ultralow-entropy states of a many-body system.

  7. Conversion of optical wave polarizations in 1D finite anisotropic photonic crystal

    International Nuclear Information System (INIS)

    Ouchani, N.; Nougaoui, N.; Daoudi, A.; Bria, D.

    2006-07-01

    We show that by using one dimensional anisotropic photonic structures, it is possible to realize optical wave polarization conversion by transmission or by reflection. Thus a single incident S(P) polarized plane wave can produce a single reflected P(S) polarized wave and a single transmitted P(S) polarized wave. This polarization conversion property can be fulfilled with a simple finite superlattice constituted by anisotropic dielectric materials. We discuss the appropriate choices of the material and geometrical properties to realize such structures. The transmission and reflection coefficients are discussed in relation with the dispersion curves of the finite structure embedded between two isotropic substrates. Both transmission and reflection coefficients are calculated in the framework of Green's function method. The amplitude and the polarization characteristics of reflected and transmitted waves are determined as function of frequency ω , and wave vector k parallel ( parallel to the interface) and the orientations of the principal axes of the layers constituting the SL. Moreover, this structure exhibits a coupling between S and P waves that does not exist in SL composed only of isotropic materials. Specific applications of these results are given for a superlattice consisting of alternating biaxial anisotropic layers NaNO 2 /SbSi sandwiched between two identical semi-infinite isotropic media. (author)

  8. Survey of holographic security systems

    Science.gov (United States)

    Kontnik, Lewis T.; Lancaster, Ian M.

    1990-04-01

    The counterfeiting of products and financial instruments is a major problem throughout the world today. The dimensions of the problem are growing, accelerated by the expanding availability of production technologies to sophisticated counterfeiters and the increasing capabilities of these technologies. Various optical techniques, including holography, are beingused in efforts to mark authentic products and to distinguish them from copies. Industry is recognizing that the effectiveness of these techniques depends on such factors as the economics of the counterfeiting process and the distribution channels for the products involved, in addition to the performance of the particular optical security technologies used. This paper surveys the nature of the growing counterfeit market place and reviews the utility of holographic optical security systems. In particular, we review the use of holograms on credit cards and other products; and outline certain steps the holography industry should take to promote these application.

  9. Research and development on optically pumped polarized ion sources. Technical progress report, July 1, 1985-June 30, 1986

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1986-07-01

    The development of an optically pumped polarized 23 Na target is discussed. The three categories of research are: (1) electron spin relaxation of the 23 Na due to wall collisions; (2) effects of radiation trapping on the polarization that can be produced in an alkali target by optical pumping; and (3) the effects of spin exchange collisions in the polarization of a fast H 0 beam formed by charge transfer as an H + beam passes through a polarized alkali target. 90 refs., 7 figs

  10. Physics and technology of optical storage in polymer thin films

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Hvilsted, Søren; Ujhelyi, F.

    2001-01-01

    We discuss different strategies for optical storage of information in polymeric films. An outline of the existing trends is given. The synthesis and characterization of side-chain azobenzene polyester films for holographic storage of information is described. A compact holographic memory card...... system based on polarization holography is described. A storage density of greater than 10MB/cm2 has been achieved so far, with a potential increase to 100MB/cm(2) using multiplexing techniques and software correction. Finally the role of surface relief in azobenzene polymers on irradiation...

  11. Polarization-dependent plasmonic splitter based on low-loss polymer optical materials

    Science.gov (United States)

    Qian, Guang; Fu, Xing-Chang; Zhang, Li-Jiang; Liu, Yi-Ran; Zhao, Ning; Zhang, Tong

    2018-01-01

    A polarization-dependent optical beam splitter consisting of a straight long-range surface plasmon polariton (LRSPP) waveguide and an S-bend polymer waveguide was designed, fabricated and measured in this paper. At the splitting section, the two different waveguides are vertically coupled. The measurenment results show that the splitter operated in dual-channel mode at TM polarization, and single-channel mode at TE polarization. In addition, the polymer waveguide and LRSPP waveguide in the splitter exhibit low propagation loss of 0.51 dB/cm and 1.7 dB/cm, respectively. The hybrid beam splitter has wide potential applications in three dimensional (3D) multilayer photonic integrated circuits (PICs).

  12. High-Order Dielectric Metasurfaces for High-Efficiency Polarization Beam Splitters and Optical Vortex Generators

    Science.gov (United States)

    Guo, Zhongyi; Zhu, Lie; Guo, Kai; Shen, Fei; Yin, Zhiping

    2017-08-01

    In this paper, a high-order dielectric metasurface based on silicon nanobrick array is proposed and investigated. By controlling the length and width of the nanobricks, the metasurfaces could supply two different incremental transmission phases for the X-linear-polarized (XLP) and Y-linear-polarized (YLP) light with extremely high efficiency over 88%. Based on the designed metasurface, two polarization beam splitters working in high-order diffraction modes have been designed successfully, which demonstrated a high transmitted efficiency. In addition, we have also designed two vortex-beam generators working in high-order diffraction modes to create vortex beams with the topological charges of 2 and 3. The employment of dielectric metasurfaces operating in high-order diffraction modes could pave the way for a variety of new ultra-efficient optical devices.

  13. Manipulation of the polarization of intense laser beams via optical wave mixing in plasmas

    Science.gov (United States)

    Michel, Pierre; Divol, Laurent; Turnbull, David; Moody, John

    2014-10-01

    When intense laser beams overlap in plasmas, the refractive index modulation created by the beat wave via the ponderomotive force can lead to optical wave mixing phenomena reminiscent of those used in crystals and photorefractive materials. Using a vector analysis, we present a full analytical description of the modification of the polarization state of laser beams crossing at arbitrary angles in a plasma. We show that plasmas can be used to provide full control of the polarization state of a laser beam, and give simple analytical estimates and practical considerations for the design of novel photonics devices such as plasma polarizers and plasma waveplates. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  14. Self-error-rejecting photonic qubit transmission in polarization-spatial modes with linear optical elements

    Science.gov (United States)

    Jiang, YuXiao; Guo, PengLiang; Gao, ChengYan; Wang, HaiBo; Alzahrani, Faris; Hobiny, Aatef; Deng, FuGuo

    2017-12-01

    We present an original self-error-rejecting photonic qubit transmission scheme for both the polarization and spatial states of photon systems transmitted over collective noise channels. In our scheme, we use simple linear-optical elements, including half-wave plates, 50:50 beam splitters, and polarization beam splitters, to convert spatial-polarization modes into different time bins. By using postselection in different time bins, the success probability of obtaining the uncorrupted states approaches 1/4 for single-photon transmission, which is not influenced by the coefficients of noisy channels. Our self-error-rejecting transmission scheme can be generalized to hyperentangled n-photon systems and is useful in practical high-capacity quantum communications with photon systems in two degrees of freedom.

  15. Synthesis of focused beam with controllable arbitrary homogeneous polarization using engineered vectorial optical fields.

    Science.gov (United States)

    Rui, Guanghao; Chen, Jian; Wang, Xiaoyan; Gu, Bing; Cui, Yiping; Zhan, Qiwen

    2016-10-17

    The propagation and focusing properties of light beams continue to remain a research interest owning to their promising applications in physics, chemistry and biological sciences. One of the main challenges to these applications is the control of polarization distribution within the focal volume. In this work, we propose and experimentally demonstrate a method for generating a focused beam with arbitrary homogeneous polarization at any transverse plane. The required input field at the pupil plane of a high numerical aperture objective lens can be found analytically by solving an inverse problem with the Richard-Wolf vectorial diffraction method, and can be experimentally created with a vectorial optical field generator. Focused fields with various polarizations are successfully generated and verified using a Stokes parameter measurement to demonstrate the capability and versatility of proposed technique.

  16. Experimental demonstration of polar coded IM/DD optical OFDM for short reach system

    Science.gov (United States)

    Fang, Jiafei; Xiao, Shilin; Liu, Ling; Bi, Meihua; Zhang, Lu; Zhang, Yunhao; Hu, Weisheng

    2017-11-01

    In this paper, we propose a novel polar coded intensity modulation direct detection (IM/DD) optical orthogonal frequency division multiplexing (OFDM) system for short reach system. A method of evaluating the channel signal noise ratio (SNR) is proposed for soft-demodulation. The experimental results demonstrate that, compared to the conventional case, ∼9.5 dB net coding gain (NCG) at the bit error rate (BER) of 1E-3 can be achieved after 40-km standard single mode fiber (SSMF) transmission. Based on the experimental result, (512,256) polar code with low complexity and satisfactory BER performance meets the requirement of low latency in short reach system, which is a promising candidate for latency-stringent short reach optical system.

  17. The polar cusp: Particle-, optical- and geomagnetic manifistations of solar wind - magnetosphere interaction

    International Nuclear Information System (INIS)

    Sandholt, P.E.; Egeland, A.; Lybekk, B.

    1985-08-01

    In this study observations of particle precipitation, optical emissions and geomagnetic disturbances associated with the low-altitude polar cusp are presented. The main observational basis is photometer data from two stations on Svalbard (Spitsbergen), Norway. These data have been used to map the location and dynamics of polar cusp auroras. One event with coordinated observations of low-energy precipitation from satellite HILAT and optical observations from the ground is discussed. Simultaneous photometer observations of the midday (Svalbard) and midnight (Alaska) sectors of the auroral oval are also presented. Thus, dynamical auroral phenomena with different temporal and spatial scales are investigated in relation to the interplanetary magnetic field and magnetospheric substorms. Certain large- and small-scale dynamics of the aurora and the geomagnetic field are shown to be consistent with the quasi steady-state/large-scale and impulsive/small-scale modes of magnetic reconnection at the frontside magnetopause

  18. Measurement of the linewidth enhancement factor based on nonlinear polarization rotation of semiconductor optical amplifier.

    Science.gov (United States)

    Liu, Guodong; Wu, Chongqing; Wang, Fu; Zhang, Tianyong; Shang, Chao; Gao, Kaiqiang

    2015-06-01

    A simple measurement scheme of the linewidth enhancement factor based on the nonlinear polarization rotation of a semiconductor optical amplifier is proposed. Considering the polarization dependent gain, the relationship between the linewidth enhancement factor and the Stokes vector was derived theoretically. It is proven that the linewidth enhancement factor can be calculated directly from the Stokes parameters without any other assistant measurement system. The results demonstrate that the linewidth enhancement factor varies in a small range from 10.5 to 8.5 for TE mode and from 8.2 to 5.8 for TM mode, respectively, when the input optical power varies from 50 μW to 1 mW and the bias current varies from 90 to 170 mA.

  19. NONINVASIVE DIAGNOSIS OF BLADDER CANCER BY CROSS-POLARIZATION OPTICAL COHERENCE TOMOGRAPHY: A BLIND STATISTICAL STUDY

    Directory of Open Access Journals (Sweden)

    O. S. Streltsova

    2014-07-01

    Full Text Available Whether cross-polarization (CP optical coherence tomography (OCT could be used to detect early bladder cancer was ascertained; it was compared with traditional OCT within the framework of blind (closed clinical statistical studies. One hundred and sixteen patients with local nonexophytic (flat pathological processes of the bladder were examined; 360 CP OCT images were obtained and analyzed. The study used an OCT 1300-U CP optical coherence tomographer. CP OCT showed a high (94% sensitivity and a high (84% specificity in the identification of suspected nonexophytic areas in the urinary bladder.

  20. Implementation of trinary logic in a polarization encoded optical shadow-casting scheme.

    Science.gov (United States)

    Rizvi, R A; Zaheer, K; Zubairy, M S

    1991-03-10

    The design of various multioutput trinary combinational logic units by a polarization encoded optical shadow-casting (POSC) technique is presented. The POSC modified algorithm is employed to design and implement these logic elements in a trinary number system with separate and simultaneous generation of outputs. A detailed solution of the POSC logic equations for a fixed source plane and a fixed decoding mask is given to obtain input pixel coding for a trinary half-adder, full adder, and subtractor.

  1. Use of polarization measurements in evaluating cascade contributions to optical excitation functions

    International Nuclear Information System (INIS)

    McConkey, J.W.

    1981-01-01

    Recent developments in theory and experimental measurements of rotational line polarization fractions of diatomic molecules following electron impact are used to show how in some instances cascade free optical excitation functions can be derived without additional measurements of the cascading contribution. The Lyman system of H 2 is presented as an example and some previously conflicting excitation cross-section measurements obtained by different techniques are reconciled

  2. Polarization measurement of atomic hydrogen beam spin-exchanged with optically oriented sodium atoms

    International Nuclear Information System (INIS)

    Ueno, Akira; Ogura, Kouichi; Wakuta, Yoshihisa; Kumabe, Isao

    1988-01-01

    The spin-exchange reaction between hydrogen atoms and optically oriented sodium atoms was used to produce a polarized atomic hydrogen beam. The electron-spin polarization of the atomic hydrogen beam, which underwent the spin-exchange reaction with the optically oriented sodium atoms, was measured. A beam polarization of -(8.0±0.6)% was obtained when the thickness and polarization of the sodium target were (5.78±0.23)x10 13 atoms/cm 2 and -(39.6±1.6)%, respectively. The value of the spin-exchange cross section in the forward scattering direction, whose scattering angle in the laboratory system was less than 1.0 0 , was obtained from the experimental results as Δσ ex =(3.39±0.34)x10 -15 cm 2 . This value is almost seven times larger than the theoretical value calculated from the Na-H potential. The potential was computed quantum mechanically in the space of the appropriate wave functions of the hydrogen and the sodium atoms. (orig./HSI)

  3. Optically initialized robust valley-polarized holes in monolayer WSe2

    KAUST Repository

    Hsu, Wei-Ting

    2015-11-25

    A robust valley polarization is a key prerequisite for exploiting valley pseudospin to carry information in next-generation electronics and optoelectronics. Although monolayer transition metal dichalcogenides with inherent spin–valley coupling offer a unique platform to develop such valleytronic devices, the anticipated long-lived valley pseudospin has not been observed yet. Here we demonstrate that robust valley-polarized holes in monolayer WSe2 can be initialized by optical pumping. Using time-resolved Kerr rotation spectroscopy, we observe a long-lived valley polarization for positive trion with a lifetime approaching 1 ns at low temperatures, which is much longer than the trion recombination lifetime (~10–20 ps). The long-lived valley polarization arises from the transfer of valley pseudospin from photocarriers to resident holes in a specific valley. The optically initialized valley pseudospin of holes remains robust even at room temperature, which opens up the possibility to realize room-temperature valleytronics based on transition metal dichalcogenides.

  4. Review of Random Phase Encoding in Volume Holographic Storage

    Directory of Open Access Journals (Sweden)

    Wei-Chia Su

    2012-09-01

    Full Text Available Random phase encoding is a unique technique for volume hologram which can be applied to various applications such as holographic multiplexing storage, image encryption, and optical sensing. In this review article, we first review and discuss diffraction selectivity of random phase encoding in volume holograms, which is the most important parameter related to multiplexing capacity of volume holographic storage. We then review an image encryption system based on random phase encoding. The alignment of phase key for decryption of the encoded image stored in holographic memory is analyzed and discussed. In the latter part of the review, an all-optical sensing system implemented by random phase encoding and holographic interconnection is presented.

  5. Fast, high-fidelity, all-optical and dynamically-controlled polarization gate using room-temperature atomic vapor

    Energy Technology Data Exchange (ETDEWEB)

    Li, Runbing [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071 (China); Zhu, Chengjie [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Deng, L.; Hagley, E. W. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

    2014-10-20

    We demonstrate a fast, all-optical polarization gate in a room-temperature atomic medium. Using a Polarization-Selective-Kerr-Phase-Shift (PSKPS) technique, we selectively write a π phase shift to one circularly-polarized component of a linearly-polarized input signal field. The output signal field maintains its original strength but acquires a 90° linear polarization rotation, demonstrating fast, high-fidelity, dynamically-controlled polarization gate operation. The intensity of the polarization-switching field used in this PKSPK-based polarization gate operation is only 2 mW/cm{sup 2}, which would be equivalent to 0.5 nW of light power (λ = 800 nm) confined in a typical commercial photonic hollow-core fiber. This development opens a realm of possibilities for potential future extremely low light level telecommunication and information processing systems.

  6. New model for assessing dose and dose rate sensitivity of Gamma ray radiation loss in polarization maintaining optical fibers

    International Nuclear Information System (INIS)

    Zhang Hongchen; Liu Hai; Qiao Wenqiang; Xue Huijie; He Shiyu

    2012-01-01

    Highlights: ► Building a new phenomenological theory model to investigate the relation about the irradiation induced loss with irradiation dose and dose rate. ► The Gamma ray irradiation induced loss of the “Capsule” type and “Panda” type polarization maintaining optical fibers at 1310 nm wavelength are investigated. ► The anti irradiation performance of the “Panda” type polarization maintaining optical fiber is better than that of the “Capsule” type polarization maintaining optical fiber, the reason is that the stress region doped by GeO 2 . - Abstract: The Gamma ray irradiation induced loss of the “Capsule” type and “Panda” type polarization maintaining optical fibers at 1310 nm wavelength are investigated. A phenomenological theory model is introduced and the influence of irradiation dose and dose rate on the irradiation induced loss is discussed. The phenomenological theoretical results are consistent with the experimental results of the irradiation induced loss for the two types of polarization maintaining optical fibers. The anti irradiation performance of the “Panda” type polarization maintaining optical fiber is better than that of the “Capsule” type polarization maintaining optical fiber, the reason is that the stress region dope with GeO 2 . Meanwhile, both of the polarization maintaining optical fiber irradiation induced loss increase with increasing the irradiation dose. In the case of same dose, the high dose rate Gamma ray irradiation induced optical fiber losses are higher than that of the low dose rate.

  7. Pattern recognition with magnonic holographic memory device

    International Nuclear Information System (INIS)

    Kozhevnikov, A.; Dudko, G.; Filimonov, Y.; Gertz, F.; Khitun, A.

    2015-01-01

    In this work, we present experimental data demonstrating the possibility of using magnonic holographic devices for pattern recognition. The prototype eight-terminal device consists of a magnetic matrix with micro-antennas placed on the periphery of the matrix to excite and detect spin waves. The principle of operation is based on the effect of spin wave interference, which is similar to the operation of optical holographic devices. Input information is encoded in the phases of the spin waves generated on the edges of the magnonic matrix, while the output corresponds to the amplitude of the inductive voltage produced by the interfering spin waves on the other side of the matrix. The level of the output voltage depends on the combination of the input phases as well as on the internal structure of the magnonic matrix. Experimental data collected for several magnonic matrixes show the unique output signatures in which maxima and minima correspond to specific input phase patterns. Potentially, magnonic holographic devices may provide a higher storage density compare to optical counterparts due to a shorter wavelength and compatibility with conventional electronic devices. The challenges and shortcoming of the magnonic holographic devices are also discussed

  8. Pulse holographic measurement techniques

    International Nuclear Information System (INIS)

    Kim, Cheol Jung; Baik, Seong Hoon; Hong, Seok Kyung; Kim, Jeong Moog; Kim, Duk Hyun

    1992-01-01

    With the development of laser, remote inspection techniques using laser have been growing on. The inspection and measurement techniques by pulse holography are well-established technique for precise measurement, and widely used in various fields of industry now. In nuclear industry, this technology is practically used because holographic inspection is remote, noncontact, and precise measurement technique. In relation to remote inspection technology in nuclear industry, state-of-the art of pulse HNDT (Holographic non-destructive testing) and holographic measurement techniques are examined. First of all, the fundamental principles as well as practical problems for applications are briefly described. The fields of pulse holography have been divided into the HNDT, flow visualization and distribution study, and other application techniques. Additionally holographic particle study, bubble chamber holography, and applications to other visualization techniques are described. Lastly, the current status for the researches and applications of pulse holography to nuclear industry which are carried out actively in Europe and USA, is described. (Author)

  9. Retinal pigment epithelium findings in patients with albinism using wide-field polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Schütze, Christopher; Ritter, Markus; Blum, Robert; Zotter, Stefan; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

    2014-11-01

    To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging. Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 × 40° on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation was analyzed qualitatively and quantitatively based on depolarization assessed by polarization-sensitive optical coherence tomography. This study revealed strong evidence of polarization-sensitive optical coherence tomography to specifically image melanin in the RPE. Depolarization of light backscattered by the RPE in patients with albinism was reduced compared with normal subjects. Heterogeneous RPE-specific depolarization characteristics were observed in patients with albinism. Reduction of depolarization observed in the light backscattered by the RPE in patients with albinism corresponds to expected decrease of RPE pigmentation. The degree of depigmentation of the RPE is possibly associated with visual acuity. Findings suggest that different albinism genotypes result in heterogeneous levels of RPE pigmentation. Polarization-sensitive optical coherence tomography showed a heterogeneous appearance of RPE pigmentation in patients with albinism depending on different genotypes.

  10. The optical polarization of M82 and the local spiral arm

    International Nuclear Information System (INIS)

    Axon, D.J.

    1977-08-01

    This thesis comprises two separate but related topics in the study of optical polarization of galaxies. In part I we investigate interstellar polarization within 2 kpc of the sun and attempt to quantify the local structure of the galactic magnetic field. In part II we report the results of polarization measurements of the peculiar galaxy M82, obtained using a new polarimeter and digital reduction techniques, and discuss models of the origin of the polarization. Measurements of the linear polarization of starlight have been collated into a catalogue containing the Stokes' parameters in galactic coordinates for those stars for which reliable distances could be determined. Assuming a magnetic alignment hypothesis we have investigated the direction and form of the galactic magnetic field through e-vector plots and from the periodicity of the Stokes' parameters Q(l) and U(l) with galactic longitude. In the second part of the thesis we describe an imaging polarimeter constructed for use with a McMullan electronographic camera and designed to operate at an f/15 focus. The instrument is intended for observations of galaxies and other nebulae to diameters of up to 8 minutes of arc and has been successfully used to observe the irregular galaxy M82 in the B-band. The results of these observations are reported in this thesis. (author)

  11. Testing the existence of optical linear polarization in young brown dwarfs

    Science.gov (United States)

    Manjavacas, E.; Miles-Páez, P. A.; Zapatero-Osorio, M. R.; Goldman, B.; Buenzli, E.; Henning, T.; Pallé, E.; Fang, M.

    2017-07-01

    Linear polarization can be used as a probe of the existence of atmospheric condensates in ultracool dwarfs. Models predict that the observed linear polarization increases with the degree of oblateness, which is inversely proportional to the surface gravity. We aimed to test the existence of optical linear polarization in a sample of bright young brown dwarfs, with spectral types between M6 and L2, observable from the Calar Alto Observatory, and cataloged previously as low gravity objects using spectroscopy. Linear polarimetric images were collected in I and R band using CAFOS at the 2.2-m telescope in Calar Alto Observatory (Spain). The flux ratio method was employed to determine the linear polarization degrees. With a confidence of 3σ, our data indicate that all targets have a linear polarimetry degree in average below 0.69 per cent in the I band, and below 1.0 per cent in the R band, at the time they were observed. We detected significant (I.e. P/σ ≥ 3) linear polarization for the young M6 dwarf 2MASS J04221413+1530525 in the R band, with a degree of p* = 0.81 ± 0.17 per cent.

  12. Analysis of polarization introduced due to the telescope optics of the Thirty Meter Telescope

    Science.gov (United States)

    Anche, Ramya Manjunath; Sen, Asoke Kumar; Anupama, Gadiyara Chakrapani; Sankarasubramanian, Kasiviswanathan; Skidmore, Warren

    2018-01-01

    An analytical model has been developed to estimate the polarization effects, such as instrumental polarization (IP), crosstalk (CT), and depolarization, due to the optics of the Thirty Meter Telescope. These are estimated for the unvignetted field-of-view and the wavelengths of interest. The model estimates an IP of 1.26% and a CT of 44% at the Nasmyth focus of the telescope at the wavelength of 0.6 μm at field angle zero with the telescope pointing to zenith. Mueller matrices have been estimated for the primary, secondary, and Nasmyth mirrors. It is found that some of the Mueller matrix elements of the primary and secondary mirrors show a fourfold azimuthal antisymmetry, which indicates that the polarization at the Cassegrain focus is negligible. At the inclined Nasmyth mirror, there is no azimuthal antisymmetry in the matrix elements, and this results in nonzero values for IP and CT, which would negatively impact the polarization measurements at the telescope focus. The averaged Mueller matrix is estimated at the Nasmyth focus at different instrument ports and various zenith angles of the telescope. The variation in the Mueller matrix elements for different coatings is also estimated. The impact of this polarization effect on the science case requirements has been discussed. This analysis will help in achieving precise requirements for future instruments with polarimetric capability.

  13. Recirculating beam-breakup thresholds for polarized higher-order modes with optical coupling

    Directory of Open Access Journals (Sweden)

    Georg H. Hoffstaetter

    2007-04-01

    Full Text Available Here we will derive the general theory of the beam-breakup (BBU instability in recirculating linear accelerators with coupled beam optics and with polarized higher-order dipole modes. The bunches do not have to be at the same radio-frequency phase during each recirculation turn. This is important for the description of energy recovery linacs (ERLs where beam currents become very large and coupled optics are used on purpose to increase the threshold current. This theory can be used for the analysis of phase errors of recirculated bunches, and of errors in the optical coupling arrangement. It is shown how the threshold current for a given linac can be computed and a remarkable agreement with tracking data is demonstrated. General formulas are then analyzed for several analytically solvable problems: (a Why can different higher order modes (HOM in one cavity couple and why can they then not be considered individually, even when their frequencies are separated by much more than the resonance widths of the HOMs? For the Cornell ERL as an example, it is noted that optimum advantage is taken of coupled optics when the cavities are designed with an x-y HOM frequency splitting of above 50 MHz. The simulated threshold current is then far above the design current of this accelerator. To justify that the simulation can represent an actual accelerator, we simulate cavities with 1 to 8 modes and show that using a limited number of modes is reasonable. (b How does the x-y coupling in the particle optics determine when modes can be considered separately? (c How much of an increase in threshold current can be obtained by coupled optics and why does the threshold current for polarized modes diminish roughly with the square root of the HOMs’ quality factors. Because of this square root scaling, polarized modes with coupled optics increase the threshold current more effectively for cavities that have rather large HOM quality factors, e.g. those without very

  14. Holographic anyonic superfluidity

    Science.gov (United States)

    Jokela, Niko; Lifschytz, Gilad; Lippert, Matthew

    2013-10-01

    Starting with a holographic construction for a fractional quantum Hall state based on the D3-D7' system, we explore alternative quantization conditions for the bulk gauge fields. This gives a description of a quantum Hall state with various filling fractions. For a particular alternative quantization of the bulk gauge fields, we obtain a holographic anyon fluid in a vanishing background magnetic field. We show that this system is a superfluid, exhibiting the relevant gapless excitation.

  15. DMSP optical and electron measurements in the vicinity of polar cap arcs

    International Nuclear Information System (INIS)

    Hardy, D.A.; Burke, W.J.; Gussenhoven, M.S.

    1982-01-01

    We have completed an extensive analysis of the electron and optical data from the DMSP satellites for an external period of polar cap arc occurrences on December 12, 1977. The polar cap arcs are observed in three distinct intervals in a period of quieting after a time of intense substorm activity. The observation of polar cap arcs is associated with the admittance of large and variable fluxes of low-energy electrons into a major portion of both the northern and southern hemisphere polar caps. These fluxes fall into the following categories: First, nearly Maxwellian distributions of electrons with temperatures between 50 eV and 200 eV and number densities varying from 0.03/cm 3 to 4/cm 3 . The highest densities are found at the poleward boundary of the diffuse aurorae and near the visible polar cap arcs. The lowest densities are associated with the polar rain. Second, distributions of electrons peaked between 50 eV and 200 eV. These distributions result from accelertion of the cold Maxwellian distribution through a potential of 50 to 200 V without any heating of the electrons. Third, distributions of electrons displaying two populations; an intense low-energy component with a temperature of approx.20 eV and a much weaker high-energy component with a temperature of 180 eV. We interpret such distributions as evidence of direct admittance of magnetosheath electrons into the polar cap. Fourth,, distributions of electrons peaked at approx.1 keV. These distributions produce the visible arcs. They result from the acceleration of a two-component electron population with temperatures of 100 and 350 eV through a potential drop of approx.750 V

  16. Holographic and acoustic emission evaluation of pressure vessels

    International Nuclear Information System (INIS)

    Boyd, D.M.

    1980-01-01

    Optical holographic interfereometry and acoustic emission monitoring were simultaneously used to evaluate two small, high pressure vessels during pressurization. The techniques provide pressure vessel designers with both quantitative information such as displacement/strain measurements and qualitative information such as flaw detection. The data from the holographic interferograms were analyzed for strain profiles. The acoustic emission signals were monitored for crack growth and vessel quality

  17. Phase-shifting Real-time Holographic Microscopy applied in micro-structures surface analysis

    International Nuclear Information System (INIS)

    Brito, I V; Gesualdi, M R R; Muramatsu, M; Ricardo, J

    2011-01-01

    The microscopic real-time analysis of micro structured materials is of great importance in various domains of science and technology. For other hand, the holographic interferometry comprises a group of powerful optical methods for non-destructive testing in surface analysis. The holographic microscopy uses the holographic interferometric techniques to obtain quantitative intensity and phase information of the optical waves by microscopic systems. With the development of CCD cameras, computers (hardware and software), and new materials for holographic recording, these techniques can be used to replace the classical form of registration and became promising tools in surface analysis. In this work, we developed a prototype of Photorefractive and Digital Holographic Microscope for real-time analysis of micro-structured systems based on the phase-shifting real-time holographic interferometry techniques. Using this apparatus, we are made analysis of shapes and surfaces to obtain the phase maps and the 3D profiles of some samples.

  18. Optical pulling force on a magneto-dielectric Rayleigh sphere in Bessel tractor polarized beams

    International Nuclear Information System (INIS)

    Mitri, F.G.; Li, R.X.; Yang, R.P.; Guo, L.X.; Ding, C.Y.

    2016-01-01

    The optical radiation force induced by Bessel (vortex) beams on a magneto-dielectric subwavelength sphere is investigated with particular emphasis on the beam polarization and order l (or topological charge). The analysis is focused on identifying the regions and some of the conditions to achieve retrograde motion of the sphere centered on the axis of wave propagation of the incident beam, or shifted off-axially. Exact non-paraxial analytical solutions are established, and computations for linear, circular, radial, azimuthal and mixed polarizations of the individual plane wave components forming the Bessel (vortex) beams by means of the angular spectrum decomposition method (ASDM) illustrate the theory with particular emphasis on the tractor (i.e. reversal) behavior of the force. This effect results in the pulling of the magneto-dielectric sphere against the forward linear momentum density flux associated with the incoming waves. Should some conditions related to the choice of the beam parameters as well as the permittivity and permeability of the sphere be met, the optical force vanishes and reverses sign. Moreover, the beam polarization is shown to affect differently the axial negative pulling force for either the zeroth- or the first-order Bessel beam. When the sphere is centered on the beam′s axis, the axial force component is always negative for the zeroth-order Bessel beam except for the radial and azimuthal polarization configurations. Nonetheless, for the first-order Bessel beam, the axial force is negative for the radial polarization case only. Additional tractor beam effects arise when the sphere departs from the center of the beam. It is also demonstrated that the tractor beam effect arises from the force component originating from the cross-interaction between the electric and magnetic dipoles. Potential applications are in particle manipulation, optical levitation, tractor beam tweezers, and other emergent technologies using polarized Bessel beams on

  19. Research and development on optically pumped polarized ion sources. Technical progress report, February 1, 1985-January 31, 1986

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1985-07-01

    During the past year we have studied the relaxation times in an optically pumped 23 Na vapor target, studied the effects of radiation trapping on the polarization in a Na vapor target, and have studied the effects of spin exchange collisions on a beam of fast H 0 atoms as they pass through a polarized alkali target. This research is directed toward improvements in the optically pumped Na or other alkali vapor targets used for the production of polarized H - ions. In this progress report we review the properties of the optically pumped polarized H - ion source as well as discussing the progress of our research on optically pumped Na or other alkali vapor targets. 81 refs., 9 figs

  20. Giant quadratic electro-optical effect during polarization switching in ultrathin ferroelectric polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Blinov, L. M., E-mail: lev39blinov@gmail.com; Lazarev, V V; Palto, S P; Yudin, S G [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2012-04-15

    The low-frequency quadratic electro-optical effect with a maximum electro-optical coefficient of g = 8 Multiplication-Sign 10{sup -19} m{sup 2}/V{sup 2} (i.e., four orders of magnitude greater than the standard high-frequency value) has been studied in thin films of ferroelectric polymer PVDF(70%)-TrFE(30%). The observed effect is related to the process of spontaneous polarization switching, during which the electron oscillators of C-F and C-H dipole groups rotate to become parallel to the applied field. As a result, the ellipsoid of the refractive index exhibits narrowing in the direction perpendicular to the field. The field dependence of the electro-optical coefficient g correlates with that of the apparent dielectric permittivity, which can be introduced under the condition of ferroelectric polarization switching. The observed electro-optical effect strongly decreases when the frequency increases up to several hundred hertz. The temperature dependence of the effect exhibits clearly pronounced hysteresis in the region of the ferroelectric phase transition.

  1. Polarization-resolved optical response of plasmonic particle-on-film nanocavities

    Science.gov (United States)

    Zhang, Q.; Li, G.-C.; Lo, T. W.; Lei, D. Y.

    2018-02-01

    Placing a metal nanoparticle atop a metal film forms a plasmonic particle-on-film nanocavity. Such a nanocavity supports strong plasmonic coupling that results in rich hybridized plasmon modes, rendering the cavity a versatile platform for exploiting a wide range of plasmon-enhanced spectroscopy applications. In this paper, we fully address the polarization-resolved, orientation-dependent far-field optical responses of plasmonic monomer- and dimer-on-film nanocavities by numerical simulations and experiments. With polarization-resolved dark-field spectroscopy, the distinct plasmon resonances of these nanocavities are clearly determined from their scattering spectra. Moreover, the radiation patterns of respective plasmon modes, which are often mixed together in common dark-field imaging, can be unambiguously resolved with our proposed quasi-multispectral imaging method. Explicitly, the radiation pattern of the monomer-on-film nanocavity gradually transitions from a solid spot in the green imaging channel to a doughnut ring in the red channel when tuning the excitation polarization from parallel to perpendicular to the sample surface. This observation holds true for the plasmonic dimer-on-film nanocavity with the dimer axis aligned in the incidence plane; when the dimer axis is normal to the incidence plane, the pattern transitions from a solid spot to a doughnut ring both in the red channel. These studies not only demonstrate a flexible polarization control over the optical responses of plasmonic particle-on-film nanostructures but also enrich the optical tool kit for far-field imaging and spectroscopy characterization of various plasmonic nanostructures.

  2. Microscopic optical path length difference and polarization measurement system for cell analysis

    Science.gov (United States)

    Satake, H.; Ikeda, K.; Kowa, H.; Hoshiba, T.; Watanabe, E.

    2018-03-01

    In recent years, noninvasive, nonstaining, and nondestructive quantitative cell measurement techniques have become increasingly important in the medical field. These cell measurement techniques enable the quantitative analysis of living cells, and are therefore applied to various cell identification processes, such as those determining the passage number limit during cell culturing in regenerative medicine. To enable cell measurement, we developed a quantitative microscopic phase imaging system based on a Mach-Zehnder interferometer that measures the optical path length difference distribution without phase unwrapping using optical phase locking. The applicability of our phase imaging system was demonstrated by successful identification of breast cancer cells amongst normal cells. However, the cell identification method using this phase imaging system exhibited a false identification rate of approximately 7%. In this study, we implemented a polarimetric imaging system by introducing a polarimetric module to one arm of the Mach-Zehnder interferometer of our conventional phase imaging system. This module was comprised of a quarter wave plate and a rotational polarizer on the illumination side of the sample, and a linear polarizer on the optical detector side. In addition, we developed correction methods for the measurement errors of the optical path length and birefringence phase differences that arose through the influence of elements other than cells, such as the Petri dish. As the Petri dish holding the fluid specimens was transparent, it did not affect the amplitude information; however, the optical path length and birefringence phase differences were affected. Therefore, we proposed correction of the optical path length and birefringence phase for the influence of elements other than cells, as a prerequisite for obtaining highly precise phase and polarimetric images.

  3. The laser control system for the TRIUMF optically pumped polarized H- ion source

    International Nuclear Information System (INIS)

    Kadantsev, S.G.; Levy, C.D.P.; Mouat, M.M.

    1994-08-01

    The optically pumped polarized H - ion source at TRIUMF produces up to 100 μΑ dc of 78% polarized beam within an emittance of 1.0 π mm mrad and is now being prepared for an upcoming experiment at TRIUMF that will measure parity violation in pp scattering at 230 MeV. The optical pumping is accomplished by argon laser pumped Ti-sapphire lasers. The laser control system provides monitoring and precision control of the lasers for fast spin reversal up to 200 s -1 . To solve the problems of laser power and frequency stabilization during fast spin flipping, techniques and algorithms have been developed that significantly reduce the variation of laser frequency and power between spin states. The upgraded Faraday rotation system allows synchronous measurement of Rb thickness and polarization while spin flipping. The X Window environment provides both local and remote control to laser operators via a local area network and X window terminals. In this new environment issues such as access authorization, response time, operator interface consistency and ease of use are of particular importance. (author)

  4. Increasing the pump-up rate to polarize 3He gas using spin-exchange optical pumping method

    International Nuclear Information System (INIS)

    Lee, W.T.; Tong Xin; Rich, Dennis; Liu Yun; Fleenor, Michael; Ismaili, Akbar; Pierce, Joshua; Hagen, Mark; Dadras, Jonny; Robertson, J. Lee

    2009-01-01

    In recent years, polarized 3 He gas has increasingly been used as neutron polarizers and polarization analyzers. Two of the leading methods to polarize the 3 He gas are the spin-exchange optical pumping (SEOP) method and the meta-stable exchange optical pumping (MEOP) method. At present, the SEOP setup is comparatively compact due to the fact that it does not require the sophisticated compressor system used in the MEOP method. The temperature and the laser power available determine the speed, at which the SEOP method polarizes the 3 He gas. For the quantity of gas typically used in neutron scattering work, this speed is independent of the quantity of the gas required, whereas the polarizing time using the MEOP method is proportional to the quantity of gas required. Currently, using the SEOP method to polarize several bar-liters of 3 He to 70% polarization would require 20-40 h. This is an order of magnitude longer than the MEOP method for the same quantity of gas and polarization. It would therefore be advantageous to speed up the SEOP process. In this article, we analyze the requirements for temperature, laser power, and the type of alkali used in order to shorten the time required to polarize 3 He gas using the SEOP method.

  5. Simultaneously improving optical absorption of both transverse-electric polarized and transverse-magnetic polarized light for organic solar cells with Ag grating used as transparent electrode

    Directory of Open Access Journals (Sweden)

    Yongbing Long

    2014-08-01

    Full Text Available Theoretical simulations are performed to investigate optical performance of organic solar cells with Ag grating electrode. It is demonstrated that optical absorption for both transverse-electric (TE polarized and transverse-magnetic(TM polarized light is simultaneously improved when compared with that for the device without the Ag grating. The improvement is respectively attributed to the resonance and the surface plasmon polaritons within the device. After an additional WO3 layer is capped on the Ag grating, absorption of TE-polarized light is further improved due to resonance of double microcavities within the device, and absorption of TM-polarized light is improved by the combined effects of the microcavity resonance and the surface plasmon polaritons. Correspondingly, the short current density for randomly polarized light is improved by 18.1% from that of the device without the Ag grating. Finally, it is demonstrated that high transmission may not be an essential prerequisite for metallic gratings when they are used as transparent electrode since absorption loss caused by low transmission can be compensated by using a capping layer to optimize optical resonance of the WMC structure within the device.

  6. Practical polarization maintaining optical fibre temperature sensor for harsh environment application

    Science.gov (United States)

    Yang, Yuanhong; Xia, Haiyun; Jin, Wei

    2007-10-01

    A reflection spot temperature sensor was proposed based on the polarization mode interference in polarization maintaining optical fibre (PMF) and the phenomenon that the propagation constant difference of the two orthogonal polarization modes in stressing structures PMF is sensitive to temperature and the sensing equation was obtained. In this temperature sensor, a broadband source was used to suppress the drift due to polarization coupling in lead-in/lead-out PMF. A characteristic and performance investigation proved this sensor to be practical, flexible and precise. Experimental results fitted the theory model very well and the noise-limited minimum detectable temperature variation is less than 0.01 °C. The electric arc processing was investigated and the differential propagation constant modifying the PMF probe is performed. For the demand of field hot-spot monitoring of huge power transformers, a remote multi-channel temperature sensor prototype has been made and tested. Specially coated Panda PMF that can stand high temperatures up to 250 °C was fabricated and used as probe fibres. The sensor probes were sealed within thin quartz tubes that have high voltage insulation and can work in a hot oil and vapour environment. Test results show that the accuracy of the system is better than ±0.5 °C within 0 °C to 200 °C.

  7. Optical CDMA with Embedded Spectral-Polarization Coding over Double Balanced Differential-Detector

    Science.gov (United States)

    Huang, Jen-Fa; Yen, Chih-Ta; Chen, Bo-Hau

    A spectral-polarization coding (SPC) optical code-division multiple-access (OCDMA) configuration structured over arrayed-waveguide grating (AWG) router is proposed. The polarization-division double balanced detector is adopted to execute difference detection and enhances system performance. The signal-to-noise ratio (SNR) is derived by taking the effect of PIIN into account. The result indicates that there would be up to 9-dB SNR improvement than the conventional spectral-amplitude coding (SAC) structures with Walsh-Hadamard codes. Mathematical deriving results of the SNR demonstrate the system embedded with the orthogonal state of polarization (SOP) will suppress effectively phase-induced intensity noise (PIIN). In addition, we will analyze the relations about bit error rate (BER) vs. the number of active users under the different encoding schemes and compare them with our proposed scheme. The BER vs. the effective power under the different encoding scheme with the same number of simultaneous active user conditions are also revealed. Finally, the polarization-matched factor and the difference between simulated and experimental values are discussed.

  8. Imaging of dental material by polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Dichtl, Sabine; Baumgartner, Angela; Hitzenberger, Christoph K.; Moritz, Andreas; Wernisch, Johann; Robl, Barbara; Sattmann, Harald; Leitgeb, Rainer; Sperr, Wolfgang; Fercher, Adolf F.

    1999-05-01

    Partial coherence interferometry (PCI) and optical coherence tomography (OCT) are noninvasive and noncontact techniques for high precision biometry and for obtaining cross- sectional images of biologic structures. OCT was initially introduced to depict the transparent tissue of the eye. It is based on interferometry employing the partial coherence properties of a light source with high spatial coherence ut short coherence length to image structures with a resolution of the order of a few microns. Recently this technique has been modified for cross section al imaging of dental and periodontal tissues. In vitro and in vivo OCT images have been recorded, which distinguish enamel, cemento and dentin structures and provide detailed structural information on clinical abnormalities. In contrast to convention OCT, where the magnitude of backscattered light as a function of depth is imaged, polarization sensitive OCT uses backscattered light to image the magnitude of the birefringence in the sample as a function of depth. First polarization sensitive OCT recordings show, that changes in the mineralization status of enamel or dentin caused by caries or non-caries lesions can result in changes of the polarization state of the light backscattered by dental material. Therefore polarization sensitive OCT might provide a new diagnostic imaging modality in clinical and research dentistry.

  9. Polarization Dependent Dynamics of CO2 Trapped in AN Optical Centrifuge

    Science.gov (United States)

    Toro, Carlos; Echebiri, Geraldine; Liu, Qingnan; Mullin, Amy S.

    2012-06-01

    An optical centrifuge (Yuan {et al}. {PNAS} 2011, 108, 6872) has been employed to prepare carbon dioxide molecules in very high rotational states (``hot'' rotors, J ˜220) in order to investigate how collisions relax ensembles of molecules with an overall angular momentum that is spatially oriented. We have performed polarization-dependent high resolution transient IR absorption measurements to study the spatial dependence of the relaxation dynamics. Our results show that the net angular momentum of the initially centrifuged molecules persists for at least 10 gas kinetic collisions and that the translational energy distributions are dependent on the probe orientation and polarization. These studies indicate that the centrifuged molecules tend to maintain the orientation of their initial angular momentum for the first set of collisions and that relatively large changes in J are involved in the first collisions.

  10. Optical Sensing of Polarization States Changes in Meat due to the Ageing

    Science.gov (United States)

    Tománek, Pavel; Mikláš, Jan; Abubaker, Hamed Mohamed; Grmela, Lubomír

    2010-11-01

    Food materials or biological materials display large compositional variations, inhomogeneities, and anisotropic structures. The biological tissues consist of cells which dimensions are bigger than a wavelength of visible light, therefore Mie scattering of transmitted and reflected light occurs and different polarization states arise. The meat industry needs reliable meat quality information throughout the production process in order to guarantee high-quality meat products for consumers. The minor importance is still given to the food quality control and inspection during processing operations or storing conditions. The paper presents a quite simple optical method allowing measure the freshness or ageing of products. The principle is to study temporal characteristics of polarization states of forward or backward scattered laser light in the samples in function of meat ageing.

  11. Optical Polarization of 1000 Stars Within 50-PARSECS from the Sun

    Science.gov (United States)

    Leroy, J. L.

    1993-11-01

    We have prepared a catalogue of optical polarization measurements for 1000 stars closer than 50 parsecs from the Sun. The distances, which are presently those given in the Sky Catalogue 2000.0, 2nd edition (Hirshfeld et al. 1991) are provisional: they will be replaced later by the much safer parallaxes which will result from the Hipparcos mission. The polarization data have been compiled, for 60% in various catalogues with due care to their accuracy for 40% they are new, unpublished, measurements obtained at Pic du Midi Observatory. We expect that this new data base will allow a better understanding of the interstellar medium around the Sun; the analysis, similar to the beautiful work by Tinbergen (1982), is to be found in a companion paper.

  12. Holographic memories with encryption-selectable function

    Science.gov (United States)

    Su, Wei-Chia; Lee, Xuan-Hao

    2006-03-01

    Volume holographic storage has received increasing attention owing to its potential high storage capacity and access rate. In the meanwhile, encrypted holographic memory using random phase encoding technique is attractive for an optical community due to growing demand for protection of information. In this paper, encryption-selectable holographic storage algorithms in LiNbO 3 using angular multiplexing are proposed and demonstrated. Encryption-selectable holographic memory is an advance concept of security storage for content protection. It offers more flexibility to encrypt the data or not optionally during the recording processes. In our system design, the function of encryption and non-encryption storage is switched by a random phase pattern and a uniform phase pattern. Based on a 90-degree geometry, the input patterns including the encryption and non-encryption storage are stored via angular multiplexing with reference plane waves at different incident angles. Image is encrypted optionally by sliding the ground glass into one of the recording waves or removing it away in each exposure. The ground glass is a key for encryption. Besides, it is also an important key available for authorized user to decrypt the encrypted information.

  13. A measurement of the absolute neutron beam polarization produced by an optically pumped 3He neutron spin filter

    International Nuclear Information System (INIS)

    Rich, D.R.; Bowman, J.D.; Crawford, B.E.; Delheij, P.P.J.; Espy, M.A.; Haseyama, T.; Jones, G.; Keith, C.D.; Knudson, J.; Leuschner, M.B.; Masaike, A.; Masuda, Y.; Matsuda, Y.; Penttilae, S.I.; Pomeroy, V.R.; Smith, D.A.; Snow, W.M.; Szymanski, J.J.; Stephenson, S.L.; Thompson, A.K.; Yuan, V.

    2002-01-01

    The capability of performing accurate absolute measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the neutron beam polarization with an absolute accuracy of 0.3% in the neutron energy range from 40 meV to 10 eV using an optically pumped polarized 3 He spin filter and a relative transmission measurement technique. 3 He was polarized using the Rb spin-exchange method. We describe the measurement technique, present our results, and discuss some of the systematic effects associated with the method

  14. Fiber-FSO/wireless convergent systems based on dual-polarization and one optical sideband transmission schemes

    Science.gov (United States)

    Huang, Xu-Hong; Lu, Hai-Han; Li, Chung-Yi; Wang, Yun-Chieh; Chang, Jen-Chieh; Jheng, Yu-Bo; Tsai, Wen-Shing

    2018-06-01

    A bidirectional fiber-free-space optical (FSO)/wireless convergent system that uses dual-polarization and one optical sideband transmission schemes for hybrid vestigial sideband (VSB)–four-level pulse amplitude modulation (PAM4)/millimeter-wave signal transmission is proposed and demonstrated. Using a dual-polarization scheme, one optical sideband that is modulated by a 56 Gb s‑1 VSB–PAM4 signal (x-polarization) and another optical sideband that is modulated by a 10 Gbps data stream (y-polarization) are separated and polarized orthogonally. One optical sideband modulated by a 10 Gbps data stream (y-polarization) is delivered to efficaciously suppress the dispersion-induced limitation due to a span of 40 km single-mode fiber (SMF) and the distortion due to the beating among multiple sidebands. The proposed bidirectional fiber-FSO/wireless convergent system is a prominent one for providing broadband integrated services, such as the Internet, telecommunication, and 5G mobile networks.

  15. The use of Lorentz group formalism in solving polarization effects of a birefringent single mode optical fiber

    International Nuclear Information System (INIS)

    Ishiekwene, G.C.; Brown, C.S.; Mensah, S.Y.; Bak, A.E.

    2000-07-01

    A theoretical analysis on the polarization effects of a light beam propagating in a birefringent single-mode fiber is presented. We derive a system of differential equations representing the evolution of Stokes parameters and illustrate their application to polarization effects in a straight birefringent single mode optical fiber. The solutions to the set of equations are obtained using specifically the methods of the unified formalism for polarization optics which adopt the use of the Stokes-Mueller equation and the Lorentz group to model polarization phenomena in media such as optical fibers. The analytical results presented using this approach are identical to results obtained from other conventional methods. We observe the characteristic exponential decrease in the total intensity of the input light due to attenuation by the fiber. (author)

  16. Optical polarization modulation by competing atomic coherence effects in a degenerate four-level Yb atomic system

    International Nuclear Information System (INIS)

    Park, Sung Jong; Park, Chang Yong; Yoon, Tai Hyun

    2005-01-01

    A scheme of optical polarization modulation of a linearly polarized infrared probe field is studied in a degenerate four-level Yb atomic system. We have observed an anomalous transmission spectra of two circular polarization components of the probe field exhibiting an enhanced two-photon absorption and a three-photon gain with comparable magnitude, leading to the lossless transmission and enhanced circular dichroism. We carried out a proof-of-principle experiment of fast optical polarization modulation in such a system by modulating the polarization state of the coupling field. The observed enhanced two-photon absorption and three-photon gain of the probe field are due to the result of competing atomic coherence effects

  17. Holographic Spherically Symmetric Metrics

    Science.gov (United States)

    Petri, Michael

    The holographic principle (HP) conjectures, that the maximum number of degrees of freedom of any realistic physical system is proportional to the system's boundary area. The HP has its roots in the study of black holes. It has recently been applied to cosmological solutions. In this article we apply the HP to spherically symmetric static space-times. We find that any regular spherically symmetric object saturating the HP is subject to tight constraints on the (interior) metric, energy-density, temperature and entropy-density. Whenever gravity can be described by a metric theory, gravity is macroscopically scale invariant and the laws of thermodynamics hold locally and globally, the (interior) metric of a regular holographic object is uniquely determined up to a constant factor and the interior matter-state must follow well defined scaling relations. When the metric theory of gravity is general relativity, the interior matter has an overall string equation of state (EOS) and a unique total energy-density. Thus the holographic metric derived in this article can serve as simple interior 4D realization of Mathur's string fuzzball proposal. Some properties of the holographic metric and its possible experimental verification are discussed. The geodesics of the holographic metric describe an isotropically expanding (or contracting) universe with a nearly homogeneous matter-distribution within the local Hubble volume. Due to the overall string EOS the active gravitational mass-density is zero, resulting in a coasting expansion with Ht = 1, which is compatible with the recent GRB-data.

  18. A circularly polarized optical dipole trap and other developments in laser trapping of atoms

    Science.gov (United States)

    Corwin, Kristan Lee

    Several innovations in laser trapping and cooling of alkali atoms are described. These topics share a common motivation to develop techniques for efficiently manipulating cold atoms. Such advances facilitate sensitive precision measurements such as parity non- conservation and 8-decay asymmetry in large trapped samples, even when only small quantities of the desired species are available. First, a cold, bright beam of Rb atoms is extracted from a magneto-optical trap (MOT) using a very simple technique. This beam has a flux of 5 × 109 atoms/s and a velocity of 14 m/s, and up to 70% of the atoms in the MOT were transferred to the atomic beam. Next, a highly efficient MOT for radioactive atoms is described, in which more than 50% of 221Fr atoms contained in a vapor cell are loaded into a MOT. Measurements were also made of the 221Fr 7 2P1/2 and 7 2P3/2 energies and hyperfine constants. To perform these experiments, two schemes for stabilizing the frequency of the light from a diode laser were developed and are described in detail. Finally, a new type of trap is described and a powerful cooling technique is demonstrated. The circularly polarized optical dipole trap provides large samples of highly spin-polarized atoms, suitable for many applications. Physical processes that govern the transfer of large numbers of atoms into the trap are described, and spin-polarization is measured to be 98(1)%. In addition, the trap breaks the degeneracy of the atomic spin states much like a magnetic trap does. This allows for RF and microwave cooling via both forced evaporation and a Sisyphus mechanism. Preliminary application of these techniques to the atoms in the circularly polarized dipole trap has successfully decreased the temperature by a factor of 4 while simultaneously increasing phase space density.

  19. Quantum properties of spin polarized helium 3 optically oriented by a LNA laser

    International Nuclear Information System (INIS)

    Leduc, M.; Laloe, F.; Nacher, P.J.; Tastevin, G.; Daniels, J.M.; Betts, D.

    1986-01-01

    Spin polarized helium 3 (/sup 3/He increasing) and also atomic hydrogen (H decreasing) are systems exhibiting a number of unusual and interesting properties at low temperature. This is true even for dilute polarized gases in spite of the weakness of the nuclear magnetic interaction between atoms. The changes in the macroscopic properties of the gas with the nuclear polarization P are pure consequences of the indistinguishability of the particles and of the symmetrization principle in quantum mechanics. The transport properties of the gas, such as viscosity and thermal conductivity, have been calculated and found to be strongly dependent on P below a few kelvins. Spin transport in /sup 3/He increasing gives rise at low temperature to collective oscillatory modes: the transverse spin waves. Large changes are also expected with P in the case of more dense /sup 3/He fluids, such as an increase with P in the saturated vapor pressure. Optical pumping is a convenient technique for efficient polarization of the nuclear spins in /sup 3/He gas/sup 2/ making use of the 2/sup 3/S-2/sup 3/P atomic line at 1.08 μm. The arrival of cw tunable lasers in the near IR in the early 1980s gave a strong impulse to the buildup of experiments with a view to measuring quantum properties of /sup 3/He increasing at low temperature. Color center lasers (F/sup +//sub 2/ in NaF) provide P values up to 70%. They are now being replaced by more easy to handle LNA lasers which have given so far P in excess of 50% at room temperature. At low temperature, direct optical pumping of a /sup 3/He cell leads to poor P values; for that reason a different technique is used

  20. Polarization-sensitive electro-optic detection of terahertz wave using three different types of crystal symmetry: Toward broadband polarization spectroscopy

    International Nuclear Information System (INIS)

    Oguchi, Kenichi; Iwasaki, Hotsumi; Okano, Makoto; Watanabe, Shinichi

    2016-01-01

    We investigated polarization-sensitive electro-optic (EO) detection of terahertz (THz) waves by using two uniaxial crystals: a c-cut gallium selenide and a c-cut lithium niobate crystals. We formulated a general frequency-domain description of EO detection by in-plane isotropic EO crystals, which holds regardless of the frequency. Based on this description, the polarization of THz waves can be derived by analyzing EO sampling signals measured with two orthogonal configurations of the in-plane isotropic EO crystals as well as typical (111) zinc-blende EO crystals. In addition, we experimentally demonstrated that the frequency-dependent polarization of THz waves can be reproducibly retrieved using three EO crystals with different crystal symmetries and with different phase matching conditions. Our description provides essential information for practical polarization sensing in the THz frequency range as well as in the mid-infrared range

  1. Dual-Wavelength Sensitized Photopolymer for Holographic Data Storage

    Science.gov (United States)

    Tao, Shiquan; Zhao, Yuxia; Wan, Yuhong; Zhai, Qianli; Liu, Pengfei; Wang, Dayong; Wu, Feipeng

    2010-08-01

    Novel photopolymers for holographic storage were investigated by combining acrylate monomers and/or vinyl monomers as recording media and liquid epoxy resins plus an amine harder as binder. In order to improve the holographic performances of the material at blue-green wavelength band two novel dyes were used as sensitizer. The methods of evaluating the holographic performances of the material, including the shrinkage and noise characteristics, are described in detail. Preliminary experiments show that samples with optimized composite have good holographic performances, and it is possible to record dual-wavelength hologram simultaneously in this photopolymer by sharing the same optical system, thus the storage density and data rate can be doubly increased.

  2. Broadband polarization-independent and low-profile optically transparent metamaterial absorber

    Science.gov (United States)

    Li, Long; Xi, Rui; Liu, Haixia; Lv, Zhiyong

    2018-05-01

    A transparent metamaterial absorber with simultaneously high optical transparency and broadband microwave absorption is presented in this paper. Consisting of a two-layer soda-lime glass substrate and three-layer patch-shaped indium tin oxide (ITO) films, the proposed absorber has advantages of broadband absorption with an absorptivity higher than 85% in the range from 6.1 to 22.1 GHz, good polarization insensitiveness, a high transparency, a low profile, and wide-incident-angle stability. A prototype of the proposed absorber is fabricated and experimentally measured to demonstrate its excellent performance. The measured results agree well with the theoretical design and numerical simulations.

  3. Analytical Solutions of Temporal Evolution of Populations in Optically-Pumped Atoms with Circularly Polarized Light

    Directory of Open Access Journals (Sweden)

    Heung-Ryoul Noh

    2016-03-01

    Full Text Available We present an analytical calculation of temporal evolution of populations for optically pumped atoms under the influence of weak, circularly polarized light. The differential equations for the populations of magnetic sublevels in the excited state, derived from rate equations, are expressed in the form of inhomogeneous second-order differential equations with constant coefficients. We present a general method of analytically solving these differential equations, and obtain explicit analytical forms of the populations of the ground state at the lowest order in the saturation parameter. The obtained populations can be used to calculate lineshapes in various laser spectroscopies, considering transit time relaxation.

  4. Characterization of dual-polarization LTE radio over a free-space optical turbulence channel.

    Science.gov (United States)

    Bohata, J; Zvanovec, S; Korinek, T; Mansour Abadi, M; Ghassemlooy, Z

    2015-08-10

    A dual polarization (DP) radio over a free-space optical (FSO) communication link using a long-term evolution (LTE) radio signal is proposed and analyzed under different turbulence channel conditions. Radio signal transmission over the DP FSO channel is experimentally verified by means of error vector magnitude (EVM) statistics. We demonstrate that such a system, employing a 64 quadrature amplitude modulation at the frequency bands of 800 MHz and 2.6 GHz, evinces reliability with LTE signal over the FSO channel is a potential solution for last-mile access or backbone networks, when using multiple-input multiple-output based DP signals.

  5. Topological events on the lines of circular polarization in nonparaxial vector optical fields.

    Science.gov (United States)

    Freund, Isaac

    2017-02-01

    In nonparaxial vector optical fields, the following topological events are shown to occur in apparent violation of charge conservation: as one translates the observation plane along a line of circular polarization (a C line), the points on the line (C points) are seen to change not only the signs of their topological charges, but also their handedness, and, at turning points on the line, paired C points with the same topological charge and opposite handedness are seen to nucleate. These counter-intuitive events cannot occur in paraxial fields.

  6. Optical code division multiple access secure communications systems with rapid reconfigurable polarization shift key user code

    Science.gov (United States)

    Gao, Kaiqiang; Wu, Chongqing; Sheng, Xinzhi; Shang, Chao; Liu, Lanlan; Wang, Jian

    2015-09-01

    An optical code division multiple access (OCDMA) secure communications system scheme with rapid reconfigurable polarization shift key (Pol-SK) bipolar user code is proposed and demonstrated. Compared to fix code OCDMA, by constantly changing the user code, the performance of anti-eavesdropping is greatly improved. The Pol-SK OCDMA experiment with a 10 Gchip/s user code and a 1.25 Gb/s user data of payload has been realized, which means this scheme has better tolerance and could be easily realized.

  7. Imaging of human breast tissue using polarization sensitive optical coherence tomography

    Science.gov (United States)

    Verma, Y.; Gautam, M.; Divakar Rao, K.; Swami, M. K.; Gupta, P. K.

    2011-12-01

    We report a study on the use of polarization sensitive optical coherence tomography (PSOCT) for discriminating malignant (invasive ductal carcinoma), benign (fibroadenoma) and normal (adipocytes) breast tissue sites. The results show that while conventional OCT, that utilizes only the intensity of light back-scattered from tissue microstructures, is able to discriminate breast tissues as normal (adipocytes) and abnormal (malignant and benign) tissues, PS-OCT helps in discriminating between malignant and benign tissue sites also. The estimated values of birefringence obtained from the PSOCT imaging show that benign breast tissue samples have significantly higher birefringence as compared to the malignant tissue samples.

  8. Optical and Micro-Structural Characterization of MBE Grown Indium Gallium Nitride Polar Quantum Dots

    KAUST Repository

    El Afandy, Rami

    2011-07-07

    Gallium nitride and related materials have ushered in scientific and technological breakthrough for lighting, mass data storage and high power electronic applications. These III-nitride materials have found their niche in blue light emitting diodes and blue laser diodes. Despite the current development, there are still technological problems that still impede the performance of such devices. Three-dimensional nanostructures are proposed to improve the electrical and thermal properties of III-nitride optical devices. This thesis consolidates the characterization results and unveils the unique physical properties of polar indium gallium nitride quantum dots grown by molecular beam epitaxy technique. In this thesis, a theoretical overview of the physical, structural and optical properties of polar III-nitrides quantum dots will be presented. Particular emphasis will be given to properties that distinguish truncated-pyramidal III-nitride quantum dots from other III-V semiconductor based quantum dots. The optical properties of indium gallium nitride quantum dots are mainly dominated by large polarization fields, as well as quantum confinement effects. Hence, the experimental investigations for such quantum dots require performing bandgap calculations taking into account the internal strain fields, polarization fields and confinement effects. The experiments conducted in this investigation involved the transmission electron microscopy and x-ray diffraction as well as photoluminescence spectroscopy. The analysis of the temperature dependence and excitation power dependence of the PL spectra sheds light on the carrier dynamics within the quantum dots, and its underlying wetting layer. A further analysis shows that indium gallium nitride quantum dots through three-dimensional confinements are able to prevent the electronic carriers from getting thermalized into defects which grants III-nitrides quantum dot based light emitting diodes superior thermally induced optical

  9. Determination of characteristics of degenerative joint disease using optical coherence tomography and polarization sensitive optical coherence tomography.

    Science.gov (United States)

    Xie, Tuqiang; Guo, Shuguang; Zhang, Jun; Chen, Zhongping; Peavy, George M

    2006-10-01

    Previous studies have demonstrated that optical coherence tomography (OCT) could be used to delineate alterations in the microstructure of cartilage, and have suggested that changes in the polarization state of light as detected by OCT could provide information on the birefringence properties of articular cartilage as influenced by disease. In this study we have used both OCT and polarization sensitive optical coherence tomography (PS-OCT) technologies to evaluate normal and abnormal bovine articular cartilage according to established structural, organizational, and birefringent characteristics of degenerative joint disease (DJD) in order to determine if this technology can be used to differentiate various stages of DJD as a minimally invasive imaging tool. Fresh bovine femoral-tibial joints were obtained from an abattoir, and 45 cartilage specimens were harvested from 8 tibial plateaus. Whole ex vivo specimens of normal and degenerative articular cartilage were imaged by both OCT and PS-OCT, then fixed and processed for histological evaluation. OCT/PS-OCT images and corresponding histology sections of each specimen were scored according to a modified Mankin structural grading scale and compared. OCT and PS-OCT imaging allowed structural evaluation of intact articular cartilage along a 6 mm surface length to a depth of 2 mm with a transverse resolution of 12 microm and an axial resolution of 10 microm. The OCT and PS-OCT images demonstrated characteristic alterations in the structure of articular cartilage with a high correlation to histological evaluation (kappa = 0.776). The OCT images were able to demonstrate early to advanced structural changes of articular cartilage while the optical phase retardation images obtained by PS-OCT imaging were able to discriminate areas where disorganization of the cartilage matrix was present, however, these characteristics are much different than those reported where OCT images alone were used to characterize tissue

  10. Holographic renormalization group and cosmology in theories with quasilocalized gravity

    International Nuclear Information System (INIS)

    Csaki, Csaba; Erlich, Joshua; Hollowood, Timothy J.; Terning, John

    2001-01-01

    We study the long distance behavior of brane theories with quasilocalized gravity. The five-dimensional (5D) effective theory at large scales follows from a holographic renormalization group flow. As intuitively expected, the graviton is effectively four dimensional at intermediate scales and becomes five dimensional at large scales. However, in the holographic effective theory the essentially 4D radion dominates at long distances and gives rise to scalar antigravity. The holographic description shows that at large distances the Gregory-Rubakov-Sibiryakov (GRS) model is equivalent to the model recently proposed by Dvali, Gabadadze, and Porrati (DGP), where a tensionless brane is embedded into 5D Minkowski space, with an additional induced 4D Einstein-Hilbert term on the brane. In the holographic description the radion of the GRS model is automatically localized on the tensionless brane, and provides the ghostlike field necessary to cancel the extra graviton polarization of the DGP model. Thus, there is a holographic duality between these theories. This analysis provides physical insight into how the GRS model works at intermediate scales; in particular it sheds light on the size of the width of the graviton resonance, and also demonstrates how the holographic renormalization group can be used as a practical tool for calculations

  11. Holographic Entanglement Entropy

    CERN Document Server

    Rangamani, Mukund

    2016-01-01

    We review the developments in the past decade on holographic entanglement entropy, a subject that has garnered much attention owing to its potential to teach us about the emergence of spacetime in holography. We provide an introduction to the concept of entanglement entropy in quantum field theories, review the holographic proposals for computing the same, providing some justification for where these proposals arise from in the first two parts. The final part addresses recent developments linking entanglement and geometry. We provide an overview of the various arguments and technical developments that teach us how to use field theory entanglement to detect geometry. Our discussion is by design eclectic; we have chosen to focus on developments that appear to us most promising for further insights into the holographic map. This is a preliminary draft of a few chapters of a book which will appear sometime in the near future, to be published by Springer. The book in addition contains a discussion of application o...

  12. The holographic universe

    CERN Document Server

    Talbot, Michael

    1991-01-01

    'There is evidence to suggest that our world and everything in it - from snowflakes to maple trees to falling stars and spinning electrons - are only ghostly images, projections from a level of reality literally beyond both space and time.' This is the astonishing idea behind the holographic theory of the universe, pioneered by two eminent thinkers: physicist David Bohm, a former protege of Albert Einstein, and quantum physicist Karl Pribram. The holographic theory of the universe encompasses consciousness and reality as we know them, but can also explain such hitherto unexplained phenomena as telepathy, out-of-body experiences and even miraculous healing. In this remarkable book, Michael Talbot reveals the extraordinary depth and power of the holographic theory of the universe, illustrating how it makes sense of the entire range of experiences within our universe - and in other universes beyond our own.

  13. Electronic-Optical Amplifier in the measurement of light polarization plane

    International Nuclear Information System (INIS)

    Miranda Diaz, Lazaro

    2009-01-01

    This paper analyzes the behavior of the output response of two electronic-optical amplifiers with constant amplitude and phase variable, in which photodiodes each them are arranged spatially 90th each other and both with their faces detection parallel to the axis of light transmission. Outward both amplifiers are going to a digital circuit that compares the fronts outputs to the front of the pulse signal that feeds the light source, to finally obtain the difference in time when fronts of light capture the photodiodes. This configuration permit to analyze the influence of the geometric arrangement of the system optical and understand the principle of why the diodes with their faces parallel to the axis of light transmission are capable of capturing variations of this, and even detect the rotation of the plane of light polarized. (Author)

  14. Computer generated holographic microtags

    International Nuclear Information System (INIS)

    Sweatt, W.C.

    1998-01-01

    A microlithographic tag comprising an array of individual computer generated holographic patches having feature sizes between 250 and 75 nanometers is disclosed. The tag is a composite hologram made up of the individual holographic patches and contains identifying information when read out with a laser of the proper wavelength and at the proper angles of probing and reading. The patches are fabricated in a steep angle Littrow readout geometry to maximize returns in the -1 diffracted order. The tags are useful as anti-counterfeiting markers because of the extreme difficulty in reproducing them. 5 figs

  15. Diffraction efficiency calculations of polarization diffraction gratings with surface relief

    Science.gov (United States)

    Nazarova, D.; Sharlandjiev, P.; Berberova, N.; Blagoeva, B.; Stoykova, E.; Nedelchev, L.

    2018-03-01

    In this paper, we evaluate the optical response of a stack of two diffraction gratings of equal one-dimensional periodicity. The first one is a surface-relief grating structure; the second, a volume polarization grating. This model is based on our experimental results from polarization holographic recordings in azopolymer films. We used films of commercially available azopolymer (poly[1-[4-(3-carboxy-4-hydroxyphenylazo) benzenesulfonamido]-1,2-ethanediyl, sodium salt]), shortly denoted as PAZO. During the recording process, a polarization grating in the volume of the material and a relief grating on the film surface are formed simultaneously. In order to evaluate numerically the optical response of this “hybrid” diffraction structure, we used the rigorous coupled-wave approach (RCWA). It yields stable numerical solutions of Maxwell’s vector equations using the algebraic eigenvalue method.

  16. Optical polarization maps of star-forming regions in Perseus, Taurus, and Ophiuchus

    International Nuclear Information System (INIS)

    Goodman, A.A.; Bastien, P.; Menard, F.; Myers, P.C.

    1990-01-01

    New optical linear polarization maps are presented of the star-forming regions near L1506 in Taurus, L1755 in Ophiuchus, and the complex of dark cloud which extends from L1448 in B5 in Perseus. The former two show a well-defined peak magnetic field direction in the plane of the sky with a finite dispersion about that peak which is smaller than would be expected for a random distribution of field distributions. The dispersion in the position angle of filamentary clouds within these complexes implies that clouds which appear elongated on the plane of the sky are not all associated with a pattern of polarization vectors particularly parallel or perpendicular to their geometry. Instead, clouds tend to be oriented at the angle formed by their axis and the mean direction of the local large-scale field. For the dark cloud complex, a bimodal distribution of the polarization vector angle is taken to result from at least two distributions of gas along the line of sight which appear as a complex in projection. 55 refs

  17. Polarization demultiplexing in stokes space for coherent optical PDM-OFDM.

    Science.gov (United States)

    Yu, Zhenming; Yi, Xingwen; Yang, Qi; Luo, Ming; Zhang, Jing; Chen, Lei; Qiu, Kun

    2013-02-11

    We propose a polarization demultiplexing method for coherent optical PDM-OFDM based on Stokes space, without inserting training symbols. The proposed approach performs well for different modulation formats of OFDM subcarrier, and shows comparable performances with that of conventional methods, but with a fast convergence speed and reduced overhead. The OFDM signal in the time domain cannot satisfy the conditions of SS-PDM accurately. Therefore, we first digitally convert the received OFDM signals to the frequency domain using fast Fourier transform (FFT). Each subcarrier of the OFDM signal has a much lower speed and narrower bandwidth, the polarization effects that it experiences can be treated as flat. Consequently, we can apply the polarization demultiplexing in Stokes space (SS-PDM) on per subcarrier basis. We verify this method in experiment by transmitting 66.6-Gb/s PDM-OFDM signal with 4QAM subcarrier modulation over 5440km SSMF and 133.3-Gb/s PDM-OFDM signal with 16QAM subcarrier modulation over 960km SSMF respectively. We also compare the results with those of training symbols. Finally, we analyze of the convergence speed of this method.

  18. Blind polarization demultiplexing by constructing a cost function for coherent optical PDM-OFDM.

    Science.gov (United States)

    Yu, Zhenming; Chen, Minghua; Chen, Hongwei; Yi, Xingwen; Yang, Sigang; Xie, Shizhong

    2015-07-13

    We propose a training symbols-free polarization demultiplexing method by constructing a cost function (CCF-PDM) for coherent optical PDM-OFDM. This method is applicable for high-speed, wide-bandwidth OFDM signals, different subcarrier modulation formats and long-haul transmission. It shows comparable performance with that of conventional method but without overhead and converges fast. Since the neighboring subcarriers experience similar polarization effects, we set the initial matrix parameters by the neighboring subcarrier to reduce the number of iteration for the gradient algorithm and prevent swapping the data of the two orthogonal polarizations. We verify this method in experiment by transmitting 66.6-Gb/s PDM-OFDM signal with 4QAM subcarrier modulation over 5440 km SSMF and 133.3-Gb/s PDM-OFDM signal with 16QAM subcarrier modulation over 960 km SSMF respectively. We compare its performance with that of training symbols. We also analyze the convergence speed of this method.

  19. Polarization-independent broadband meta-holograms via polarization-dependent nanoholes.

    Science.gov (United States)

    Zhang, Xiaohu; Li, Xiong; Jin, Jinjin; Pu, Mingbo; Ma, Xiaoliang; Luo, Jun; Guo, Yinghui; Wang, Changtao; Luo, Xiangang

    2018-05-17

    Composed of ultrathin metal or dielectric nanostructures, metasurfaces can manipulate the phase, amplitude and polarization of electromagnetic waves at a subwavelength scale, which is promising for flat optical devices. In general, metasurfaces composed of space-variant anisotropic units are sensitive to the incident polarization due to the inherent polarization dependent geometric phase. Here, we implement polarization-independent broadband metasurface holograms constructed by polarization-dependent anisotropic elliptical nanoholes by elaborate design of complex amplitude holograms. The fabricated meta-hologram exhibits a polarization insensitive feature with an acceptable image quality. We verify the feasibility of the design algorithm for three-dimensional (3D) meta-holograms with simulation and the feasibility for two-dimensional (2D) meta-holograms is experimentally demonstrated at a broadband wavelength range from 405 nm to 632.8 nm. The effective polarization-independent broadband complex wavefront control with anisotropic elliptical nanoholes proposed in this paper greatly promotes the practical applications of the metasurface in technologies associated with wavefront manipulation, such as flat lens, colorful holographic displays and optical storage.

  20. A smart-pixel holographic competitive learning network

    Science.gov (United States)

    Slagle, Timothy Michael

    Neural networks are adaptive classifiers which modify their decision boundaries based on feedback from externally- or internally-generated error signals. Optics is an attractive technology for neural network implementation because it offers the possibility of parallel, nearly instantaneous computation of the weighted neuron inputs by the propagation of light through the optical system. Using current optical device technology, system performance levels of 3 × 1011 connection updates per second can be achieved. This thesis presents an architecture for an optical competitive learning network which offers advantages over previous optical implementations, including smart-pixel-based optical neurons, phase- conjugate self-alignment of a single neuron plane, and high-density, parallel-access weight storage, interconnection, and learning in a volume hologram. The competitive learning algorithm with modifications for optical implementation is described, and algorithm simulations are performed for an example problem. The optical competitive learning architecture is then introduced. The optical system is simulated using the ``beamprop'' algorithm at the level of light propagating through the system components, and results showing competitive learning operation in agreement with the algorithm simulations are presented. The optical competitive learning requires a non-linear, non-local ``winner-take-all'' (WTA) neuron function. Custom-designed smart-pixel WTA neuron arrays were fabricated using CMOS VLSI/liquid crystal technology. Results of laboratory tests of the WTA arrays' switching characteristics, time response, and uniformity are then presented. The system uses a phase-conjugate mirror to write the self-aligning interconnection weight holograms, and energy gain is required from the reflection to minimize erasure of the existing weights. An experimental system for characterizing the PCM response is described. Useful gains of 20 were obtained with a polarization

  1. Significant and variable linear polarization during the prompt optical flash of GRB 160625B.

    Science.gov (United States)

    Troja, E.; Lipunov, V. M.; Mundell, C. G.; Butler, N. R.; Watson, A. M.; Kobayashi, S.; Cenko, S. B.; Marshall, F. E.; Ricci, R.; Fruchter, A.; Wieringa, M. H.; Gorbovskoy, E. S.; Kornilov, V.; Kutyrev, A.; Lee, W. H.; Toy, V.; Tyurina, N. V.; Budnev, N. M.; Buckley, D. A. H.; González, J.; Gress, O.; Horesh, A.; Panasyuk, M. I.; Prochaska, J. X.; Ramirez-Ruiz, E.; Rebolo Lopez, R.; Richer, M. G.; Roman-Zuniga, C.; Serra-Ricart, M.; Yurkov, V.; Gehrels, N.

    2017-07-01

    Newly formed black holes of stellar mass launch collimated outflows (jets) of ionized matter that approach the speed of light. These outflows power prompt, brief and intense flashes of γ-rays known as γ-ray bursts (GRBs), followed by longer-lived afterglow radiation that is detected across the electromagnetic spectrum. Measuring the polarization of the observed GRB radiation provides a direct probe of the magnetic fields in the collimated jets. Rapid-response polarimetric observations of newly discovered bursts have probed the initial afterglow phase, and show that, minutes after the prompt emission has ended, the degree of linear polarization can be as high as 30 per cent - consistent with the idea that a stable, globally ordered magnetic field permeates the jet at large distances from the central source. By contrast, optical and γ-ray observations during the prompt phase have led to discordant and often controversial results, and no definitive conclusions have been reached regarding the origin of the prompt radiation or the configuration of the magnetic field. Here we report the detection of substantial (8.3 ± 0.8 per cent from our most conservative simulation), variable linear polarization of a prompt optical flash that accompanied the extremely energetic and long-lived prompt γ-ray emission from GRB 160625B. Our measurements probe the structure of the magnetic field at an early stage of the jet, closer to its central black hole, and show that the prompt phase is produced via fast-cooling synchrotron radiation in a large-scale magnetic field that is advected from the black hole and distorted by dissipation processes within the jet.

  2. Holographic renormalization and supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Genolini, Pietro Benetti [Mathematical Institute, University of Oxford,Woodstock Road, Oxford OX2 6GG (United Kingdom); Cassani, Davide [LPTHE, Sorbonne Universités UPMC Paris 6 and CNRS, UMR 7589,F-75005, Paris (France); Martelli, Dario [Department of Mathematics, King’s College London,The Strand, London, WC2R 2LS (United Kingdom); Sparks, James [Mathematical Institute, University of Oxford,Woodstock Road, Oxford OX2 6GG (United Kingdom)

    2017-02-27

    Holographic renormalization is a systematic procedure for regulating divergences in observables in asymptotically locally AdS spacetimes. For dual boundary field theories which are supersymmetric it is natural to ask whether this defines a supersymmetric renormalization scheme. Recent results in localization have brought this question into sharp focus: rigid supersymmetry on a curved boundary requires specific geometric structures, and general arguments imply that BPS observables, such as the partition function, are invariant under certain deformations of these structures. One can then ask if the dual holographic observables are similarly invariant. We study this question in minimal N=2 gauged supergravity in four and five dimensions. In four dimensions we show that holographic renormalization precisely reproduces the expected field theory results. In five dimensions we find that no choice of standard holographic counterterms is compatible with supersymmetry, which leads us to introduce novel finite boundary terms. For a class of solutions satisfying certain topological assumptions we provide some independent tests of these new boundary terms, in particular showing that they reproduce the expected VEVs of conserved charges.

  3. The holographic entropy cone

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Ning [Institute for Quantum Information and Matter, California Institute of Technology,Pasadena, CA 91125 (United States); Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Nezami, Sepehr [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94305 (United States); Ooguri, Hirosi [Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo,Kashiwa 277-8583 (Japan); Stoica, Bogdan [Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Sully, James [Theory Group, SLAC National Accelerator Laboratory, Stanford University,Menlo Park, CA 94025 (United States); Walter, Michael [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94305 (United States)

    2015-09-21

    We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phase space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.

  4. The holographic entropy cone

    International Nuclear Information System (INIS)

    Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael

    2015-01-01

    We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phase space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.

  5. An optical and near-infrared polarization survey of Seyfert and broad-line radio galaxies. Pt. 1

    International Nuclear Information System (INIS)

    Brindle, C.; Hough, J.H.; Bailey, J.A.; Axon, D.J.; Ward, M.J.; McLean, I.S.

    1990-01-01

    We present new broad-band optical and near-infrared (0.44-2.2 μm) flux density and polarization measurements of a sample of 71 Seyfert galaxies and three broad-line radio galaxies. We confirm the results of earlier studies which show that the polarization of Seyferts is generally low in the V-band and at longer wavelengths, but in the B-band somewhat higher polarizations are commonly found. After correction has been made for the effects of stellar dilution, we find that Seyfert 2 nuclei are probably more highly polarized than Seyfert 1's. The small sample of Seyfert 2's selected using the 'warm' IRAS colour criterion tend to be more highly polarised than those selected by optical techniques. (author)

  6. Plasmonic non-concentric nanorings array as an unidirectional nano-optical conveyor belt actuated by polarization rotation.

    Science.gov (United States)

    Jiang, Min; Wang, Guanghui; Jiao, Wenxiang; Ying, Zhoufeng; Zou, Ningmu; Ho, Ho-Pui; Sun, Tianyu; Zhang, Xuping

    2017-01-15

    We report a nano-optical conveyor belt containing an array of gold plasmonic non-concentric nanorings (PNNRs) for the realization of trapping and unidirectional transportation of nanoparticles through rotating the polarization of an excitation beam. The location of hot spots within an asymmetric plasmonic nanostructure is polarization dependent, thus making it possible to manipulate a trapped target by rotating the incident polarization state. In the case of PNNR, the two poles have highly unbalanced trap potential. This greatly enhances the chance of transferring trapped particles between adjacent PNNRs in a given direction through rotating the polarization. As confirmed by three-dimensional finite-difference time-domain analysis, an array of PNNRs forms an unidirectional nano-optical conveyor belt, which delivers target nanoparticles or biomolecules over a long distance with nanometer accuracy. With the capacity to trap and to transfer, our design offers a versatile scheme for conducting mechanical sample manipulation in many on-chip optofluidic applications.

  7. Holographic patterning of organic-inorganic photopolymerizable nanocomposites

    Science.gov (United States)

    Sakhno, Oksana V.; Goldenberg, Leonid M.; Smirnova, Tatiana N.; Stumpe, J.

    2009-09-01

    We present here novel easily processible organic-inorganic nanocomposites suitable for holographic fabrication of diffraction optical elements (DOE). The nanocomposites are based on photocurable acrylate monomers and inorganic nanoparticles (NP). The compatibility of inorganic NP with monomers was achieved by capping the NP surface with proper organic shells. Surface modification allows to introduce up to 50wt.% of inorganic NP in organic media. Depending on the NP nature (metal oxides, phosphates, semiconductors, noble metals) and their properties, the materials for both efficient DOE and multifunctional elements can be designed. Organic-inorganic composites prepared have been successfully used for the effective inscription of periodic volume refractive index structures using the holographic photopolymerization method. The nanocomposite preparation procedure, their properties and optical performance of holographic gratings are reported. The use of functional NP makes it possible to obtain effective holographic gratings having additional physical properties such as light-emission or NLO. Some examples of such functional polymer-NP structures and their possible application fields are presented. The combination of easy photo-patterning of soft organic compounds with physical properties of inorganic materials in new nanocomposites and the flexibility of the holographic patterning method allow the fabrication of mono- and multifunctional one- and multi-dimensional passive or active optical and photonic elements.

  8. Design of frequency-encoded data-based optical master-slave-JK flip-flop using polarization switch

    Science.gov (United States)

    Mandal, Sumana; Mandal, Dhoumendra; Mandal, Mrinal Kanti; Garai, Sisir Kumar

    2017-06-01

    An optical data processing and communication system provides enormous potential bandwidth and a very high processing speed, and it can fulfill the demands of the present generation. For an optical computing system, several data processing units that work in the optical domain are essential. Memory elements are undoubtedly essential to storing any information. Optical flip-flops can store one bit of optical information. From these flip-flop registers, counters can be developed. Here, the authors proposed an optical master-slave (MS)-JK flip-flop with the help of two-input and three-input optical NAND gates. Optical NAND gates have been developed using semiconductor optical amplifiers (SOAs). The nonlinear polarization switching property of an SOA has been exploited here, and it acts as a polarization switch in the proposed scheme. A frequency encoding technique is adopted for representing data. A specific frequency of an optical signal represents a binary data bit. This technique of data representation is helpful because frequency is the fundamental property of a signal, and it remains unaltered during reflection, refraction, absorption, etc. throughout the data propagation. The simulated results enhance the admissibility of the scheme.

  9. Polarization-independent rapidly tunable optical add-drop multiplexer utilizing non-polarizing beam splitters in Ti:LiNbO3

    Science.gov (United States)

    Shin, Yong-Wook; Sung, Won Ju; Eknoyan, O.; Madsen, C. K.; Taylor, H. F.

    2012-04-01

    A polarization-independent four-port wavelength-tunable optical add drop multiplexer (OADM) that utilizes non-polarizing relaxed beam splitters has been analyzed and demonstrated in Ti:LiNbO3 at the 1530 nm wavelength regime. The design utilizes an asymmetric interferometer configuration with strain induced index grating for polarization coupling along its arms that are shifted in position relative to each other. Experimental results of the filter response agree with theoretical predictions. Electrooptic tuning over a range of 15.7 nm at a rate of 0.08 nm/V has been measured. A temporal response < 46 ns to a 20 V step change in tuning voltage has been demonstrated. Fiber-to-fiber insertion loss is ~ 6.5 dB.

  10. Holographic associative memories in document retrieval systems

    International Nuclear Information System (INIS)

    Becker, P.J.; Bolle, H.; Keller, A.; Kistner, W.; Riecke, W.D.; Wagner, U.

    1979-03-01

    The objective of this work was the implementation of a holographic memory with associative readout for a document retrieval system. Taking advantage of the favourable properties of holography - associative readout of the memory, parallel processing in the response store - may give shorter response times than sequentially organized data memories. Such a system may also operate in the interactive mode including chain associations. In order to avoid technological difficulties, the experimental setup made use of commercially available components only. As a result an improved holographic structure is proposed which uses volume holograms in photorefractive crystals as storage device. In two chapters of appendix we give a review of the state of the art of electrooptic devices for coherent optical data processing and of competing technologies (semiconductor associative memories and associative program systems). (orig.) [de

  11. Chaos synchronization in vertical-cavity surface-emitting laser based on rotated polarization-preserved optical feedback.

    Science.gov (United States)

    Nazhan, Salam; Ghassemlooy, Zabih; Busawon, Krishna

    2016-01-01

    In this paper, the influence of the rotating polarization-preserved optical feedback on the chaos synchronization of a vertical-cavity surface-emitting laser (VCSEL) is investigated experimentally. Two VCSELs' polarization modes (XP) and (YP) are gradually rotated and re-injected back into the VCSEL. The anti-phase dynamics synchronization of the two polarization modes is evaluated using the cross-correlation function. For a fixed optical feedback, a clear relationship is found between the cross-correlation coefficient and the polarization angle θp. It is shown that high-quality anti-phase polarization-resolved chaos synchronization is achieved at higher values of θp. The maximum value of the cross-correlation coefficient achieved is -0.99 with a zero time delay over a wide range of θp beyond 65° with a poor synchronization dynamic at θp less than 65°. Furthermore, it is observed that the antiphase irregular oscillation of the XP and YP modes changes with θp. VCSEL under the rotating polarization optical feedback can be a good candidate as a chaotic synchronization source for a secure communication system.

  12. Linear Transformation of the Polarization Modes in Coiled Optical Spun-Fibers with Strong Unperturbed Linear Birefringence. I. Nonresonant Transformation

    Science.gov (United States)

    Malykin, G. B.; Pozdnyakova, V. I.

    2018-03-01

    A linear transformation of orthogonal polarization modes in coiled optical spun-fibers with strong unperturbed linear birefringence, which causes the emergence of the dependences of the integrated elliptical birefringence and the ellipticity and azimuth of the major axis of the ellipse, as well as the polarization state of radiation (PSR), on the length of optical fiber has been considered. Optical spun-fibers are subjected to a strong mechanical twisting, which is frozen into the structure of the optical fiber upon cooling, in the process of being drawn out from the workpiece. Since the values of the local polarization parameters of coiled spunwaveguides vary according to a rather complex law, the calculations were carried out by numerical modeling of the parameters of the Jones matrices. Since the rotation speed of the axes of the birefringence is constant on a relatively short segment of a coiled optical spun-fiber in the accompanying torsion (helical) coordinate system, the so-called "Ginzburg helical polarization modes" (GHPMs)—two mutually orthogonal ellipses with the opposite directions of traversal, the axis of which rotate relative to the fixed coordinate system uniformly and unidirectionally—are approximately the local normal polarization modes of such optical fiber. It has been shown that, despite the fact that the unperturbed linear birefringence of the spun-fibers significantly exceeds the linear birefringence, which is caused by the winding on a coil, the integral birefringence of an extended segment of such a fiber coincides in order of magnitude with the linear birefringence, which is caused by the winding on the coil, and the integral polarization modes tend asymptotically to circular ones. It has been also shown that the values of the circular birefringence of twisted single-mode fibers, which were calculated in a nonrotating and torsion helical coordinate systems, differ significantly. It has been shown that the polarization phenomena occur

  13. Spin exchange optical pumping based polarized 3He filling station for the Hybrid Spectrometer at the Spallation Neutron Source.

    Science.gov (United States)

    Jiang, C Y; Tong, X; Brown, D R; Culbertson, H; Graves-Brook, M K; Hagen, M E; Kadron, B; Lee, W T; Robertson, J L; Winn, B

    2013-06-01

    The Hybrid Spectrometer (HYSPEC) is a new direct geometry spectrometer at the Spallation Neutron Source at the Oak Ridge National Laboratory. This instrument is equipped with polarization analysis capability with 60° horizontal and 15° vertical detector coverages. In order to provide wide angle polarization analysis for this instrument, we have designed and built a novel polarized (3)He filling station based on the spin exchange optical pumping method. It is designed to supply polarized (3)He gas to HYSPEC as a neutron polarization analyzer. In addition, the station can optimize the (3)He pressure with respect to the scattered neutron energies. The depolarized (3)He gas in the analyzer can be transferred back to the station to be repolarized. We have constructed the prototype filling station. Preliminary tests have been carried out demonstrating the feasibility of the filling station. Here, we report on the design, construction, and the preliminary results of the prototype filling station.

  14. Polarization-dependent optical characterization of poly(phenylquinoxaline) thin films

    Science.gov (United States)

    Ksianzou, V.; Velagapudi, R. K.; Grimm, B.; Schrader, S.

    2006-09-01

    Linear optical properties of two types of poly(phenylquinoxaline) (PPQ) are studied by multiwavelength prism coupling technique and optical absorption spectroscopy. Surface roughness measurements are done using atomic force microscopy. PPQs form smooth films of high optical quality having refractive indices above 1.7 in the visible and near infrared spectral ranges. Enhanced birefringence of Δn ˜0.04 has been observed in both PPQ films prepared by spin coating. Sellmeier coefficients are derived for the wavelength range starting from 0.532to1.064μm for both TE and TM polarizations. Quantum chemical calculations both on the semiempirical and on the ab initio level are carried out in order to calculate the first-order molecular polarizability tensors of the polymer repeat units. From the obtained tensor elements, theoretical values for both the average refractive indices and the maximum expectable birefringence are calculated. Based on these values a more detailed interpretation of the experimental findings is carried out. The dispersion of refractive index is quantified by the value of Abbe's constant (νd). In our case the value νd≈11 indicates high dispersion in the visible spectral range. The imaginary part k of the complex refractive index n*=n-ik reaches values of k ⩽10-3 in the wavelength range from 0.5to1μm.

  15. Reverse polarity optical-OFDM (RPO-OFDM): dimming compatible OFDM for gigabit VLC links.

    Science.gov (United States)

    Elgala, Hany; Little, Thomas D C

    2013-10-07

    Visible light communications (VLC) technology permits the exploitation of light-emitting diode (LED) luminaries for simultaneous illumination and broadband wireless communication. Optical orthogonal frequency-division multiplexing (O-OFDM) is a promising modulation technique for VLC systems, in which the real-valued O-OFDM baseband signal is used to modulate the instantaneous power of the optical carrier to achieve gigabit data rates. However, a major design challenge that limits the commercialization of VLC is how to incorporate the industry-preferred pulse-width modulation (PWM) light dimming technique while maintaining a broadband and reliable communication link. In this work, a novel signal format, reverse polarity O-OFDM (RPO-OFDM), is proposed to combine the fast O-OFDM communication signal with the relatively slow PWM dimming signal, where both signals contribute to the effective LED brightness. The advantages of using RPO-OFDM include, (1) the data rate is not limited by the frequency of the PWM signal, (2) the LED dynamic range is fully utilized to minimize the nonlinear distortion of the O-OFDM communication signal, and (3) the bit-error performance is sustained over a large fraction of the luminaire dimming range. In addition, RPO-OFDM offers a practical approach to utilize off-the-shelf LED drivers. We show results of numerical simulations to study the trade-offs between the PWM duty cycle, average electrical O-OFDM signal power, radiated optical flux as well as human perceived light.

  16. Neutron spin filter based on optically polarized sup 3 He in a near-zero magnetic field

    CERN Document Server

    Skoy, V R; Sorokin, V N; Kolachevsky, N N; Sobelman, I I; Sermyagin, A V

    2003-01-01

    A test of polarization of sup 3 He nuclei via spin-exchange collisions with optically pumped rubidium atoms in an extremely low applied magnetic field was carried out. Permalloy magnetic shields were used to prevent a fast relaxation of sup 3 He polarization owing to the inhomogeneity of a surrounding magnetic field. The whole installation was placed at the neutron beam line of the IBR-30 facility, and used as a neutron spin filter. Thus, a prototype of new design of neutron polarizer was introduced. We intend to apply this experience for the full-scale KaTRIn facility to test the time reversal violation in neutron-nuclear reactions.

  17. A holographic waveguide based eye tracker

    Science.gov (United States)

    Liu, Changgeng; Pazzucconi, Beatrice; Liu, Juan; Liu, Lei; Yao, Xincheng

    2018-02-01

    We demonstrated the feasibility of using holographic waveguide for eye tracking. A custom-built holographic waveguide, a 20 mm x 60 mm x 3 mm flat glass substrate with integrated in- and out-couplers, was used for the prototype development. The in- and out-couplers, photopolymer films with holographic fringes, induced total internal reflection in the glass substrate. Diffractive optical elements were integrated into the in-coupler to serve as an optical collimator. The waveguide captured images of the anterior segment of the eye right in front of it and guided the images to a processing unit distant from the eye. The vector connecting the pupil center (PC) and the corneal reflex (CR) of the eye was used to compute eye position in the socket. An eye model, made of a high quality prosthetic eye, was used prototype validation. The benchtop prototype demonstrated a linear relationship between the angular eye position and the PC/CR vector over a range of 60 horizontal degrees and 30 vertical degrees at a resolution of 0.64-0.69 degrees/pixel by simple pixel count. The uncertainties of the measurements at different angular positions were within 1.2 pixels, which indicated that the prototype exhibited a high level of repeatability. These results confirmed that the holographic waveguide technology could be a feasible platform for developing a wearable eye tracker. Further development can lead to a compact, see-through eye tracker, which allows continuous monitoring of eye movement during real life tasks, and thus benefits diagnosis of oculomotor disorders.

  18. Optics

    CERN Document Server

    Mathieu, Jean Paul

    1975-01-01

    Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

  19. Exploring neural cell dynamics with digital holographic microscopy

    KAUST Repository

    Marquet, Pierre; Depeursinge, Christian D.; Magistretti, Pierre J.

    2013-01-01

    In this review, we summarize how the new concept of digital optics applied to the field of holographic microscopy has allowed the development of a reliable and flexible digital holographic quantitative phase microscopy (DH-QPM) technique at the nanoscale particularly suitable for cell imaging. Particular emphasis is placed on the original biological ormation provided by the quantitative phase signal. We present the most relevant DH-QPM applications in the field of cell biology, including automated cell counts, recognition, classification, three-dimensional tracking, discrimination between physiological and pathophysiological states, and the study of cell membrane fluctuations at the nanoscale. In the last part, original results show how DH-QPM can address two important issues in the field of neurobiology, namely, multiple-site optical recording of neuronal activity and noninvasive visualization of dendritic spine dynamics resulting from a full digital holographic microscopy tomographic approach. Copyright © 2013 by Annual Reviews.

  20. Exploring neural cell dynamics with digital holographic microscopy

    KAUST Repository

    Marquet, Pierre

    2013-07-11

    In this review, we summarize how the new concept of digital optics applied to the field of holographic microscopy has allowed the development of a reliable and flexible digital holographic quantitative phase microscopy (DH-QPM) technique at the nanoscale particularly suitable for cell imaging. Particular emphasis is placed on the original biological ormation provided by the quantitative phase signal. We present the most relevant DH-QPM applications in the field of cell biology, including automated cell counts, recognition, classification, three-dimensional tracking, discrimination between physiological and pathophysiological states, and the study of cell membrane fluctuations at the nanoscale. In the last part, original results show how DH-QPM can address two important issues in the field of neurobiology, namely, multiple-site optical recording of neuronal activity and noninvasive visualization of dendritic spine dynamics resulting from a full digital holographic microscopy tomographic approach. Copyright © 2013 by Annual Reviews.

  1. Real-time holographic endoscopy

    Science.gov (United States)

    Smigielski, Paul; Albe, Felix; Dischli, Bernard

    1992-08-01

    Some new experiments concerning holographic endoscopy are presented. The quantitative measurements of deformations of objects are obtained by the double-exposure and double- reference beam method, using either a cw-laser or a pulsed laser. Qualitative experiments using an argon laser with time-average holographic endoscopy are also presented. A video film on real-time endoscopic holographic interferometry was recorded with the help of a frequency-doubled YAG-laser working at 25 Hz for the first time.

  2. Intelligent holographic databases

    Science.gov (United States)

    Barbastathis, George

    Memory is a key component of intelligence. In the human brain, physical structure and functionality jointly provide diverse memory modalities at multiple time scales. How could we engineer artificial memories with similar faculties? In this thesis, we attack both hardware and algorithmic aspects of this problem. A good part is devoted to holographic memory architectures, because they meet high capacity and parallelism requirements. We develop and fully characterize shift multiplexing, a novel storage method that simplifies disk head design for holographic disks. We develop and optimize the design of compact refreshable holographic random access memories, showing several ways that 1 Tbit can be stored holographically in volume less than 1 m3, with surface density more than 20 times higher than conventional silicon DRAM integrated circuits. To address the issue of photorefractive volatility, we further develop the two-lambda (dual wavelength) method for shift multiplexing, and combine electrical fixing with angle multiplexing to demonstrate 1,000 multiplexed fixed holograms. Finally, we propose a noise model and an information theoretic metric to optimize the imaging system of a holographic memory, in terms of storage density and error rate. Motivated by the problem of interfacing sensors and memories to a complex system with limited computational resources, we construct a computer game of Desert Survival, built as a high-dimensional non-stationary virtual environment in a competitive setting. The efficacy of episodic learning, implemented as a reinforced Nearest Neighbor scheme, and the probability of winning against a control opponent improve significantly by concentrating the algorithmic effort to the virtual desert neighborhood that emerges as most significant at any time. The generalized computational model combines the autonomous neural network and von Neumann paradigms through a compact, dynamic central representation, which contains the most salient features

  3. Sol-Gel Glass Holographic Light-Shaping Diffusers

    Science.gov (United States)

    Yu, Kevin; Lee, Kang; Savant, Gajendra; Yin, Khin Swe (Lillian)

    2005-01-01

    Holographic glass light-shaping diffusers (GLSDs) are optical components for use in special-purpose illumination systems (see figure). When properly positioned with respect to lamps and areas to be illuminated, holographic GLSDs efficiently channel light from the lamps onto specified areas with specified distributions of illumination for example, uniform or nearly uniform irradiance can be concentrated with intensity confined to a peak a few degrees wide about normal incidence, over a circular or elliptical area. Holographic light diffusers were developed during the 1990s. The development of the present holographic GLSDs extends the prior development to incorporate sol-gel optical glass. To fabricate a holographic GLSD, one records a hologram on a sol-gel silica film formulated specially for this purpose. The hologram is a quasi-random, micro-sculpted pattern of smoothly varying changes in the index of refraction of the glass. The structures in this pattern act as an array of numerous miniature lenses that refract light passing through the GLSD, such that the transmitted light beam exhibits a precisely tailored energy distribution. In comparison with other light diffusers, holographic GLSDs function with remarkably high efficiency: they typically transmit 90 percent or more of the incident lamp light onto the designated areas. In addition, they can withstand temperatures in excess of 1,000 C. These characteristics make holographic GLSDs attractive for use in diverse lighting applications that involve high temperatures and/or requirements for high transmission efficiency for ultraviolet, visible, and near-infrared light. Examples include projectors, automobile headlights, aircraft landing lights, high-power laser illuminators, and industrial and scientific illuminators.

  4. Investigation into constant envelope orthogonal frequency division multiplexing for polarization-division multiplexing coherent optical communication

    Science.gov (United States)

    Li, Yupeng; Ding, Ding

    2017-09-01

    Benefiting from the high spectral efficiency and low peak-to-average power ratio, constant envelope orthogonal frequency division multiplexing (OFDM) is a promising technique in coherent optical communication. Polarization-division multiplexing (PDM) has been employed as an effective way to double the transmission capacity in the commercial 100 Gb/s PDM-QPSK system. We investigated constant envelope OFDM together with PDM. Simulation results show that the acceptable maximum launch power into the fiber improves 10 and 6 dB for 80- and 320-km transmission, respectively (compared with the conventional PDM OFDM system). The maximum reachable distance of the constant envelope OFDM system is able to reach 800 km, and even 1200 km is reachable if an ideal erbium doped fiber amplifier is employed.

  5. Dipole field measurement technique utilizing the Faraday rotation effect in polarization preserving optical fibers

    International Nuclear Information System (INIS)

    Haddock, C.; Tong, M.Y.M.

    1989-10-01

    TRIUMF is presently in the project definition stage of its proposed KAON factory. The facility will require approximately 300 dipole magnets. The rapid measurement of representative parameters of these magnets, in particular effective length, is one of the challenges to be met. As well as the commissioning of a.c magnetic field measurement systems based on established techniques a project is underway to investigate an alternative method utilizing the Faraday Rotation effect in polarization preserving optical fibers. It is shown that a fiber equivalent to a Faraday cell can be constructed by winding a fiber in a such a way that the induced beat length L p is equal to (2n+1) times the bending circumference, with n integer. Background to the subject and preliminary results of the measurements are reported in this paper

  6. Polar optical phonons in a semiconductor quantum-well: The complete matching problem

    International Nuclear Information System (INIS)

    Nieto, J.M.; Comas, F.

    2007-01-01

    Confined polar optical phonons in a semiconductor quantum-well (QW) are studied by applying a phenomenological theory which was proposed a few years ago and is based on a continuum approach. This theory considers the coupled character of the electromechanical vibrations and takes due account of both the electric and mechanical boundary conditions. In the present work, we have applied the so-called complete matching problem in contrast with all previous published works on the subject, where more restrictive approximate boundary conditions has been applied. We also consider the effects of strains at the interfaces on the phonon spectra. Comparisons with previous works are made, while we focused on the study of a ZnTe/CdTe/ZnTe QW

  7. Giant vesicles (GV) in colloidal system under the optical polarization microscope (OPM).

    Science.gov (United States)

    Khalid, Khalisanni; Noh, Muhammad Azri Mohd; Khan, M Niyaz; Ishak, Ruzaina; Penney, Esther; Chowdhury, Zaira Zaman; Hamzah, Mohammad Hafiz; Othman, Maizatulnisa

    2017-09-01

    This paper discusses the unprecedented microscopic findings of micellar growth in colloidal system (CS) of catalyzed piperidinolysis of ionized phenyl salicylate (PS - ). The giant vesicles (GV) was observed under the optical polarization microscope (OPM) at [NaX]=0.1M where X=3-isopropC 6 H 4 O - . The conditions were rationalized from pseudo-first-order rate constant, k obs of PS - of micellar phase at 31.1×10 -3 s -1 reported in previous publication. The overall diameter of GV (57.6μm) in CS (CTABr/NaX/H 2 O)-catalyzed piperidinolysis (where X=3-isopropC 6 H 4 O) of ionized phenyl salicylate were found as giant unilamellar vesicles (GUV) and giant multilamellar vesicles (GMV). The findings were also validated by means of rheological analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Hyperentanglement concentration for polarization-spatial-time-bin hyperentangled photon systems with linear optics

    Science.gov (United States)

    Wang, Hong; Ren, Bao-Cang; Alzahrani, Faris; Hobiny, Aatef; Deng, Fu-Guo

    2017-10-01

    Hyperentanglement has significant applications in quantum information processing. Here we present an efficient hyperentanglement concentration protocol (hyper-ECP) for partially hyperentangled Bell states simultaneously entangled in polarization, spatial-mode and time-bin degrees of freedom (DOFs) with the parameter-splitting method, where the parameters of the partially hyperentangled Bell states are known to the remote parties. In this hyper-ECP, only one remote party is required to perform some local operations on the three DOFs of a photon, only the linear optical elements are considered, and the success probability can achieve the maximal value. Our hyper-ECP can be easily generalized to concentrate the N-photon partially hyperentangled Greenberger-Horne-Zeilinger states with known parameters, where the multiple DOFs have largely improved the channel capacity of long-distance quantum communication. All of these make our hyper-ECP more practical and useful in high-capacity long-distance quantum communication.

  9. A helical optical for circular polarized UV-FEL project at the UVSOR

    Energy Technology Data Exchange (ETDEWEB)

    Hama, Hiroyuki [Institute for Molecular Science, Okazaki (Japan)

    1995-12-31

    Most of existing storage ring free electron lasers (SRFEL) are restricted those performances by degradation of mirrors in optical cavities. In general, the SRFEL gain at the short wavelength region with high energy electrons is quite low, and the high reflectivity mirrors such as dielectric multilayer mirrors are therefore required. The mirror degradation is considered as a result of irradiation of higher harmonic photons that are simultaneously emitted from planar optical klystron (OK) type undulators, which are commonly used in SRFEL. This problem is getting severer as the lasing wavelength becomes shorter. The UVSOR-FEL had been originally scheduled to be shutdown by 1996 because another undulator project for spectroscopic studies with circular polarized photon would take the FEL`s place. According to suggestion of the insertion device group of the SPring-8, we have designed a helical undulator that is able to vary degree and direction of the polarization easily. In addition, the undulator can be converted into a helical OK by replacing magnets at the center part of undulator in order to coexist with further FEL experiments. Using a calculated magnetic field for magnet configurations of the OK mode, the radiation spectrum at wide wavelength range was simulated by a Fourier transform of Lienard-Wiechert potentials. As a matter of course, some higher harmonics are radiated on the off-axis angle. However it was found out that the higher harmonics is almost negligible as far as inside a solid angle of the Gaussian laser mode. Moreover the gain at the UV region of 250 nm is expected to be much higher than our present FEL because of high brilliant fundamental radiation. The calculated spatial distribution of higher harmonics and the estimated instantaneous gain is presented. Advantages of the helical OK for SRFEL will be discussed in view of our experience, and a possibility of application two-color experiment with SR will be also mentioned.

  10. The hand-hold polarization-sensitive spectral domain optical coherence and its applications

    Science.gov (United States)

    Liu, Hao; Gao, Wanrong

    2017-08-01

    The polarization-sensitive spectral domain optical coherence tomography (PSOCT) has the advantages of being able to measure the polarization properties of samples, such as phase-retardation, diattenuation, depolarization, and optical axis orientation, providing a contrast to identify the diseased area and normal area in tissues in PSOCT images. Conventionally, the sample arm of PSOCT is fixed on the stage where biomedical tissues or models is placed, and the OCT images is acquired by scanning with a galvanometer-based mirror. To be applied in the practical diagnosis, a promising way is to design a hand-held device. To this end, it is required that probe is assembled with a small volume to allow for comprehensively imaging large tissues areas at a microscopic scale, and is available to move on different samples to be acquired quickly with negligible motion artifacts. Meanwhile, the probe should be manufactured wih well stability to avoid system jitter error while it is used to detect the biological tissues in vivo. In this work, a design of a hand-hold fiber-based PSOCT is described. The device is of the size of 10 cm (length) × 8 cm (width) × 6 cm (height). Both the axial resolution and the imaging depth of the system are measured and were approximately 7 μm and 2.5 mm in air, respectively, which are in good agreement with the theoretical predictions. The A-scan rate of the system is 70 kHz. The structure is compact and all the components are fixed on the shell to reduce the motion artifact, resulting in a great stability on measuring the tissues in vivo. The cross sectional images of ex vivo chicken breast, ex vivo pork cartilage and in vivo forearm skin of human wolunteer are presented to demonstrate the capability of the system.

  11. Visibility of trabecular meshwork by standard and polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Yasuno, Yoshiaki; Yamanari, Masahiro; Kawana, Keisuke; Miura, Masahiro; Fukuda, Shinichi; Makita, Shuichi; Sakai, Shingo; Oshika, Tetsuro

    2010-11-01

    Polarization-sensitive optical coherence tomography (PS-OCT) is known to be advantageous because of its additional tissue-specific contrast of the anterior eye. So far, this advantage has been shown only qualitatively. We evaluate the improved visibility afforded by 3-D PS corneal and anterior eye segment OCT (PS-CAS-OCT) in visualizing the trabecular meshwork (TM) based on statistical evidences. A total of 31 normal subjects participated in this study. The anterior eye segments of both the eyes of the subjects are scanned using a custom-made PS-CAS-OCT and the standard-scattering OCT (S-OCT) and polarization-sensitive phase-retardation OCT (P-OCT) images are obtained. Three graders grade the visibility of the TM using a four-leveled grading system. The intergrader agreement, intermodality differences, and interquadrant dependence of visibility are statistically examined. All three of three combinations of graders show substantial agreement in visibility with P-OCT (ρ = 0.74, 0.70, and 0.68, Spearman's correlation), while only one of three shows substantial agreement with S-OCT (ρ = 0.72). Significant dependence of the visibility on the modality (S-OCT versus P-OCT) and quadrants are found by the analysis of variance. A subsequent Wilcoxon signed-rank test reveals significantly improved visibility. PS-CAS-OCT may become a useful tool for screening angle-closure glaucoma.

  12. Deriving covariant holographic entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Xi [School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540 (United States); Lewkowycz, Aitor [Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Rangamani, Mukund [Center for Quantum Mathematics and Physics (QMAP), Department of Physics, University of California, Davis, CA 95616 (United States)

    2016-11-07

    We provide a gravitational argument in favour of the covariant holographic entanglement entropy proposal. In general time-dependent states, the proposal asserts that the entanglement entropy of a region in the boundary field theory is given by a quarter of the area of a bulk extremal surface in Planck units. The main element of our discussion is an implementation of an appropriate Schwinger-Keldysh contour to obtain the reduced density matrix (and its powers) of a given region, as is relevant for the replica construction. We map this contour into the bulk gravitational theory, and argue that the saddle point solutions of these replica geometries lead to a consistent prescription for computing the field theory Rényi entropies. In the limiting case where the replica index is taken to unity, a local analysis suffices to show that these saddles lead to the extremal surfaces of interest. We also comment on various properties of holographic entanglement that follow from this construction.

  13. Utilization of Field Enhancement in Plasmonic Waveguides for Subwavelength Light-Guiding, Polarization Handling, Heating, and Optical Sensing.

    Science.gov (United States)

    Dai, Daoxin; Wu, Hao; Zhang, Wei

    2015-10-09

    Plasmonic nanostructures have attracted intensive attention for many applications in recent years because of the field enhancement at the metal/dielectric interface. First, this strong field enhancement makes it possible to break the diffraction limit and enable subwavelength optical waveguiding, which is desired for nanophotonic integrated circuits with ultra-high integration density. Second, the field enhancement in plasmonic nanostructures occurs only for the polarization mode whose electric field is perpendicular to the metal/dielectric interface, and thus the strong birefringence is beneficial for realizing ultra-small polarization-sensitive/selective devices, including polarization beam splitters, and polarizers. Third, plasmonic nanostructures provide an excellent platform of merging electronics and photonics for some applications, e.g., thermal tuning, photo-thermal detection, etc. Finally, the field enhancement at the metal/dielectric interface helps a lot to realize optical sensors with high sensitivity when introducing plasmonic nanostrutures. In this paper, we give a review for recent progresses on the utilization of field enhancement in plasmonic nanostructures for these applications, e.g., waveguiding, polarization handling, heating, as well as optical sensing.

  14. Utilization of Field Enhancement in Plasmonic Waveguides for Subwavelength Light-Guiding, Polarization Handling, Heating, and Optical Sensing

    Directory of Open Access Journals (Sweden)

    Daoxin Dai

    2015-10-01

    Full Text Available Plasmonic nanostructures have attracted intensive attention for many applications in recent years because of the field enhancement at the metal/dielectric interface. First, this strong field enhancement makes it possible to break the diffraction limit and enable subwavelength optical waveguiding, which is desired for nanophotonic integrated circuits with ultra-high integration density. Second, the field enhancement in plasmonic nanostructures occurs only for the polarization mode whose electric field is perpendicular to the metal/dielectric interface, and thus the strong birefringence is beneficial for realizing ultra-small polarization-sensitive/selective devices, including polarization beam splitters, and polarizers. Third, plasmonic nanostructures provide an excellent platform of merging electronics and photonics for some applications, e.g., thermal tuning, photo-thermal detection, etc. Finally, the field enhancement at the metal/dielectric interface helps a lot to realize optical sensors with high sensitivity when introducing plasmonic nanostrutures. In this paper, we give a review for recent progresses on the utilization of field enhancement in plasmonic nanostructures for these applications, e.g., waveguiding, polarization handling, heating, as well as optical sensing.

  15. Flowing holographic anyonic superfluid

    Science.gov (United States)

    Jokela, Niko; Lifschytz, Gilad; Lippert, Matthew

    2014-10-01

    We investigate the flow of a strongly coupled anyonic superfluid based on the holographic D3-D7' probe brane model. By analyzing the spectrum of fluctuations, we find the critical superfluid velocity, as a function of the temperature, at which the flow stops being dissipationless when flowing past a barrier. We find that at a larger velocity the flow becomes unstable even in the absence of a barrier.

  16. High-power fiber laser with a polarizing diffraction grating milled on the facet of an optical fiber

    Czech Academy of Sciences Publication Activity Database

    Vaněk, Martin; Vaniš, Jan; Baravets, Yauhen; Todorov, Filip; Čtyroký, Jiří; Honzátko, Pavel

    2016-01-01

    Roč. 24, č. 26 (2016), s. 30225-30233 ISSN 1094-4087 R&D Projects: GA ČR GA15-07908S Institutional support: RVO:67985882 Keywords : Optical fibers * Polarization * Diffraction gratings Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.307, year: 2016

  17. 61.3-Gbps hybrid fiber-wireless in-home network enabled by optical heterodyne and polarization multiplexing

    NARCIS (Netherlands)

    Cao, Z.; Li, F.; Liu, Y.; Yu, J.; Wang, Q.; Oh, C.W.; Jiao, Y.; Tran, N.C.; Boom, van den H.P.A.; Tangdiongga, E.; Koonen, A.M.J.

    2014-01-01

    A hybrid fiber-wireless in-home network is proposed to support high-speed multiple input and multiple output (MIMO) orthogonal frequency division multiplexing systems operating at millimeter wave (mm-wave) band by employing optical heterodyne (OH) and polarization multiplexing (PolMux). OH enables

  18. High-power fiber laser with a polarizing diffraction grating milled on the facet of an optical fiber

    Czech Academy of Sciences Publication Activity Database

    Vaněk, Martin; Vaniš, Jan; Baravets, Yauhen; Todorov, Filip; Čtyroký, Jiří; Honzátko, Pavel

    2016-01-01

    Roč. 24, č. 26 (2016), s. 30225-30233 ISSN 1094-4087 R&D Projects: GA ČR GA15-07908S Institutional support: RVO:67985882 Keywords : Optical fiber s * Polarization * Diffraction gratings Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.307, year: 2016

  19. Detection of 320 Gb/s Nyquist OTDM by polarization-insensitive time-domain optical Fourier transformation

    DEFF Research Database (Denmark)

    Hu, Hao; Kong, Deming; Palushani, Evarist

    2013-01-01

    320 Gb/s Nyquist-OTDM is generated by rectangular filtering with a bandwidth of 320 GHz and received by polarization-insensitive time-domain optical Fourier transformation (TD-OFT) followed by passive filtering. After the time-to-frequency mapping in the TD-OFT, the Nyquist-OTDM is converted into...

  20. Optically stimulated slowing of polar heavy-atom molecules with a constant beat phase

    Science.gov (United States)

    Yin, Yanning; Xu, Supeng; Xia, Meng; Xia, Yong; Yin, Jianping

    2018-04-01

    Polar heavy-atom molecules have been well recognized as promising candidates for precision measurements and tests of fundamental physics. A much slower molecular beam to increase the interaction time should lead to a more sensitive measurement. Here we theoretically demonstrate the possibility of the stimulated longitudinal slowing of heavy-atom molecules by the coherent optical bichromatic force with a constant beat phase. Taking the YbF meolecule as an example, we show that a rapid and short-distance deceleration of heavy molecules by a phase-compensation method is feasible with moderate conditions. A molecular beam of YbF with a forward velocity of 120 m/s can be decelerated below 10 m/s within a distance of 3.5 cm and with a laser irradiance for each traveling wave of 107.2 W/cm 2 . Our proposed slowing method could be a promising approach to break through the space constraint or the limited capture efficiency of molecules loadable into a magneto-optical trap in traditional deceleration schemes, opening the possibility for a significant improvement of the precision measurement sensitivity.

  1. Stochastic theory of polarized light in nonlinear birefringent media: An application to optical rotation

    Science.gov (United States)

    Tsuchida, Satoshi; Kuratsuji, Hiroshi

    2018-05-01

    A stochastic theory is developed for the light transmitting the optical media exhibiting linear and nonlinear birefringence. The starting point is the two-component nonlinear Schrödinger equation (NLSE). On the basis of the ansatz of “soliton” solution for the NLSE, the evolution equation for the Stokes parameters is derived, which turns out to be the Langevin equation by taking account of randomness and dissipation inherent in the birefringent media. The Langevin equation is converted to the Fokker-Planck (FP) equation for the probability distribution by employing the technique of functional integral on the assumption of the Gaussian white noise for the random fluctuation. The specific application is considered for the optical rotation, which is described by the ellipticity (third component of the Stokes parameters) alone: (i) The asymptotic analysis is given for the functional integral, which leads to the transition rate on the Poincaré sphere. (ii) The FP equation is analyzed in the strong coupling approximation, by which the diffusive behavior is obtained for the linear and nonlinear birefringence. These would provide with a basis of statistical analysis for the polarization phenomena in nonlinear birefringent media.

  2. The collagen structure of bovine intervertebral disc studied using polarization-sensitive optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Matcher, Stephen J; Winlove, C Peter; Gangnus, Sergei V [Present address: JSC ' Saratovneftegeophysics' , Saratov (Russian Federation)

    2004-04-07

    Polarization-sensitive optical coherence tomography (PS-OCT) is used to measure the birefringence properties of bovine intervertebral disc and equine flexor tendon. For equine tendon the birefringence {delta}n is (6.0 {+-} 0.2) x 10{sup -3} at a wavelength of 1.3 {mu}m. This is somewhat larger than the values reported for bovine tendon. The surface region of the annulus fibrosus of a freshly excised intact bovine intervertebral disc displays an identical value of birefringence, {delta}n = (6.0 {+-} 0.6) x 10{sup -3} at 1.3 {mu}m. The nucleus pulposus does not display birefringence, the measured apparent value of {delta}n = (0.39 {+-} 0.01) x 10{sup -3} being indistinguishable from the effects of depolarization due to multiple scattering. A clear difference is found between the depth-resolved retardance of equine tendon and that of bovine intervertebral disc. This apparently relates to the lamellar structure of the latter tissue, in which the collagen fibre orientation alternates between successive lamellae. A semi-empirical model based on Jones calculus shows that the measurements are in reasonable agreement with previous optical and x-ray data. These results imply that PS-OCT could be a useful tool to study collagen organization within the intervertebral disc in vitro and possibly in vivo and its variation with applied load and disease.

  3. The collagen structure of bovine intervertebral disc studied using polarization-sensitive optical coherence tomography

    International Nuclear Information System (INIS)

    Matcher, Stephen J; Winlove, C Peter; Gangnus, Sergei V

    2004-01-01

    Polarization-sensitive optical coherence tomography (PS-OCT) is used to measure the birefringence properties of bovine intervertebral disc and equine flexor tendon. For equine tendon the birefringence Δn is (6.0 ± 0.2) x 10 -3 at a wavelength of 1.3 μm. This is somewhat larger than the values reported for bovine tendon. The surface region of the annulus fibrosus of a freshly excised intact bovine intervertebral disc displays an identical value of birefringence, Δn = (6.0 ± 0.6) x 10 -3 at 1.3 μm. The nucleus pulposus does not display birefringence, the measured apparent value of Δn = (0.39 ± 0.01) x 10 -3 being indistinguishable from the effects of depolarization due to multiple scattering. A clear difference is found between the depth-resolved retardance of equine tendon and that of bovine intervertebral disc. This apparently relates to the lamellar structure of the latter tissue, in which the collagen fibre orientation alternates between successive lamellae. A semi-empirical model based on Jones calculus shows that the measurements are in reasonable agreement with previous optical and x-ray data. These results imply that PS-OCT could be a useful tool to study collagen organization within the intervertebral disc in vitro and possibly in vivo and its variation with applied load and disease

  4. Optical fibers with low nonlinearity and low polarization-mode dispersion for terabit communications

    Science.gov (United States)

    Baghdadi, J. A.; Safaai-Jazi, A.; Hattori, H. T.

    2001-07-01

    Refractive-index nonlinearities have negligible effect on the performance of short-haul fiber-optic communication links utilizing electronic repeaters. However, in long links, nonlinearities can cause severe signal degradations. To mitigate nonlinear effects, a new generation of fibers, referred to as large effective-area fibers, have been introduced in recent years. This paper reviews the latest research and development work on these fibers conducted by several research groups around the world. Attention is focused on a class of large effective-area fibers that are based on a depressed-core multiple-cladding design. Another important issue in long-haul and high capacity fiber optic systems is the polarization-mode dispersion (PMD) which has been recognized as a serious limiting factor. In this paper, an improved fiber design is proposed which, in addition to providing large effective-area and low bending loss, eliminates PMD due to elliptical deformation in the single-mode wavelength region. Furthermore, this design is allowed to provide a small chromatic dispersion about few ps/ nm km , in order to overcome four-wave mixing effects.

  5. Diffuse reflectance spectroscopy and optical polarization imaging of in-vivo biological tissue

    Science.gov (United States)

    Mora-Núñez, A.; Castillejos, Y.; García-Torales, G.; Martínez-Ponce, G.

    2013-11-01

    A number of optical techniques have been reported in the scientific literature as accomplishable methodologies to diagnose diseases in biological tissue, for instance, diffuse reflectance spectroscopy (DRS) and optical polarization imaging (OPI). The skin is the largest organ in the body and consists of three primary layers, namely, the epidermis (the outermost layer exposed to the world), the dermis, and the hypodermis. The epidermis changes from to site to site, mainly because of difference in hydration. A lower water content increase light scattering and reduce the penetration depth of radiation. In this work, two hairless mice have been selected to evaluate their skin features by using DRS and OPI. Four areas of the specimen body were chosen to realize the comparison: back, abdomen, tail, and head. From DRS, it was possible to distinguish the skin nature because of different blood irrigation at dermis. In the other hand, OPI shows pseudo-depolarizing regions in the measured Mueller images related to a spatially varying propagation of the scattered light. This provides information about the cell size in the irradiated skin.

  6. First-principles calculation of the polarization-dependent force driving the Eg mode in bismuth under optical excitation.

    Science.gov (United States)

    Murray, Eamonn; Fahy, Stephen

    2014-03-01

    Using first principles electronic structure methods, we calculate the induced force on the Eg (zone centre transverse optical) phonon mode in bismuth immediately after absorption of polarized light. When radiation with polarization perpendicular to the c-axis is absorbed in bismuth, the distribution of excited electrons and holes breaks the three-fold rotational symmetry and leads to a net force on the atoms in the direction perpendicular to the axis. We calculate the initial excited electronic distribution as a function of photon energy and polarization and find the resulting transverse and longitudinal forces experienced by the atoms. Using the measured, temperature-dependent rate of decay of the transverse force[2], we predict the approximate amplitude of induced atomic motion in the Eg mode as a function of temperature and optical fluence. This work is supported by Science Foundation Ireland and a Marie Curie International Incoming Fellowship.

  7. Holographic patterning of luminescent photopolymer nanocomposites

    International Nuclear Information System (INIS)

    Sakhno, Oksana V.; Smirnova, Tatiana N.; Goldenberg, Leonid M.; Stumpe, Joachim

    2008-01-01

    Volume phase gratings in the photopolymerisable composites, containing luminescent nanoparticles have been fabricated for the first time. Nanoparticles of LaPO 4 , doped by Ce 3+ and Tb 3+ ions (the trade name is REN-X-green) with high luminescence quantum yield were used as a luminescent inorganic additive. The holographic gratings in such materials are formed as a result of the diffusion distribution of the nanoparticles during exposure of photopolymerisable composites to interference pattern. The influence of the pre-polymer formulation and the holographic patterning parameters on the grating formation is comprehensively investigated. The use of the optimised pre-polymer syrup containing two monomers with sufficiently different polymerisation rates allows fabrication of gratings with diffraction efficiency up to 80% at low optical losses (< 5%) (20 μm film thickness). To obtain maximum diffraction efficiency the intensity and the period of the interference pattern were optimised for each formulation. In addition maximum diffraction efficiency was achieved with the nanocomposites containing 30-32 wt.% of nanoparticles. On the other hand the highest possible modulation of the nanoparticles' concentration was obtained for the concentration of about 20 wt.%. In this case maximum ordering of the nanoparticles in the polymer matrix is achieved. The photoluminescence of the nanoparticles within the homogeneous polymer film and within the grating has been measured. The example application of the photopolymerisable composite containing luminescence inorganic nanoparticles in holographic security technology has been demonstrated

  8. Photoanisotropic polarization gratings beyond the small recording angle regime

    NARCIS (Netherlands)

    Xu, M.; De Boer, D.K.G.; Van Heesch, C.M.; Wachters, A.J.H.; Urbach, H.P.

    2010-01-01

    Polarization gratings can be realized by polarization holographic recording in photoanisotropic materials. In this paper, we study two types of polarization gratings. One is recorded with two orthogonally circularly (OC) polarized beams and the other one with two orthogonally linearly (OL) polarized

  9. Holographic interferometry of high pressure

    International Nuclear Information System (INIS)

    McIlwain, M.E.

    1987-01-01

    Measurements in turbulent flows have been historically performed using various types of probes and optical diagnostic methods. In general, probes suffer from plasma perturbation effects and are single point determination methods. Optical methods appear to be better suited to determinations in turbulent flows, however interpretation of the resulting data can often be complex. Methods such as laser Doppler anemometry, which relies on entrained particles, suffers from the fact that particles small enough to be swept along by the plasma are usually melted or sublimed in the plasma. Light refraction or diffraction methods such as shadow photography, interferometry, and holography have also been used to observe plasma flows. These methods typically suffer from the difficulty of interpreting line of sight images and obtaining quantitative data. A new method based on multi-pass holographic interferometry will be discussed. This method has certain advantages which can significantly simplify the complexity of line of sight interferometry image deconvolution. When the method employs high speed cinematography, time resolved images of the plasma flow can be obtained. This method has been applied to both transferred and non-transferred arcs and various types of DC-plasma torch produced jets. These studies and conclusions as to the usefulness of the technique are presented

  10. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  11. Holographic interaction effects on transport in Dirac semimetals

    NARCIS (Netherlands)

    Jacobs, V.P.J.; Vandoren, S.; Stoof, H.T.C.

    2014-01-01

    Strongly interacting Dirac semimetals are investigated using a holographic model especially geared to compute the single-particle correlation function for this case, including both interaction effects and non-zero temperature. We calculate the (homogeneous) optical conductivity at zero chemical

  12. Holographic gratings for spectrographic applications: Study of aberrations

    Science.gov (United States)

    Bhatia, M. S.

    1975-01-01

    The design and fabrication of holographic gratings requires an understanding of Fermat's principle. This principle states that the path of a light ray from one point to another is that which requires the least time. The aberrant, optical path of an object point to an image was studied using Fermat principles.

  13. Detection of oral early cancerous lesion by using polarization-sensitive optical coherence tomography: mice model

    Science.gov (United States)

    Lee, Hong-Yi; Chen, Ping-Hsien; Lee, Tzu-Han; Chang, Kuo-Wei; Kuo, Wen-Chuan

    2018-02-01

    Oral cancer is the 11th most common cancer worldwide, especially in a male adult. The median age of death in oral cancer was 55 years, 10-20 years earlier than other cancers. Presently, oral cancer is often found in late stage, because the lesion is often flat in early stage and is difficult to diagnose under traditional white light imaging. The only definitive method for determining cancer is an invasive biopsy and then using histology examination. How to detect precancerous lesions or early malignant lesions is an important issue for improving prognosis of oral cancer. Optical coherence tomography (OCT) is a new optical tool for diagnosing early malignant lesions in the skin or gastrointestinal tract recently. Here we report a new method for detecting precancerous or early malignant oral lesions by using swept source polarization-sensitive optical coherence tomography (PS-OCT) with center-wavelength 1310 nm, bandwidth 110 nm and 100 kHz swept rate. We used all single-mode fiber design to detect the change of birefringence information in the epithelium structure. This system has an advantage that enables measurement of backscattered intensity and birefringence simultaneously with only one A-scan per transverse location. In preliminary result, we computed the slope of the every A-scan signal in tissue part using a linear-curve fitting in backscattered intensity and birefringence on the enface. In this research, we used an oral cancer mice model for observing the change of structure and birefringence properties in different stages of oral cancer mice. We presented the parametric enface imaging that can detect the early oral malignant lesions.

  14. Segmentation and quantification of retinal lesions in age-related macular degeneration using polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Baumann, Bernhard; Gotzinger, Erich; Pircher, Michael; Sattmann, Harald; Schuutze, Christopher; Schlanitz, Ferdinand; Ahlers, Christian; Schmidt-Erfurth, Ursula; Hitzenberger, Christoph K

    2010-01-01

    We present polarization-sensitive optical coherence tomography (PS-OCT) for quantitative assessment of retinal pathologies in age-related macular degeneration (AMD). On the basis of the polarization scrambling characteristics of the retinal pigment epithelium, novel segmentation algorithms were developed that allow one to segment pathologic features such as drusen and atrophic zones in dry AMD as well as to determine their dimensions. Results from measurements in the eyes of AMD patients prove the ability of PS-OCT for quantitative imaging based on the retinal features polarizing properties. Repeatability measurements were performed in retinas diagnosed with drusen and geographic atrophy in order to evaluate the performance of the described methods. PS-OCT appears as a promising imaging modality for three-dimensional retinal imaging and ranging with additional contrast based on the structures' tissue-inherent polarization properties.

  15. Analysis of CMOS Compatible Cu-Based TM-Pass Optical Polarizer

    KAUST Repository

    Ng, Tien Khee; Khan, Mohammed Zahed Mustafa; Al-Jabr, Ahmad Ali; Ooi, Boon S.

    2012-01-01

    for the polarizer, it was found that the metal-insulator-metal (MIM) polarizer structure is superior compared to the insulator-metal-insulator polarizer structure due to its higher polarization extinction ratio (PER) and low insertion loss. An optimized MIM TM

  16. Precise real-time polarization measurement of terahertz electromagnetic waves by a spinning electro-optic sensor.

    Science.gov (United States)

    Yasumatsu, Naoya; Watanabe, Shinichi

    2012-02-01

    We propose and develop a method to quickly and precisely determine the polarization direction of coherent terahertz electromagnetic waves generated by femtosecond laser pulses. The measurement system consists of a conventional terahertz time-domain spectroscopy system with the electro-optic (EO) sampling method, but we add a new functionality in the EO crystal which is continuously rotating with the angular frequency ω. We find a simple yet useful formulation of the EO signal as a function of the crystal orientation, which enables a lock-in-like detection of both the electric-field amplitude and the absolute polarization direction of the terahertz waves with respect to the probe laser pulse polarization direction at the same time. The single measurement finishes around two periods of the crystal rotations (∼21 ms), and we experimentally prove that the accuracy of the polarization measurement does not suffer from the long-term amplitude fluctuation of the terahertz pulses. Distribution of the measured polarization directions by repeating the measurements is excellently fitted by a gaussian distribution function with a standard deviation of σ = 0.56°. The developed technique is useful for the fast direct determination of the polarization state of the terahertz electromagnetic waves for polarization imaging applications as well as the precise terahertz Faraday or Kerr rotation spectroscopy.

  17. Near-field characteristics of highly non-paraxial subwavelength optical fields with hybrid states of polarization

    International Nuclear Information System (INIS)

    Chen Rui-Pin; Gao Teng-Yue; Chew Khian-Hooi; Dai Chao-Qing; Zhou Guo-Quan; He Sai-Ling

    2017-01-01

    The vectorial structure of an optical field with hybrid states of polarization (SoP) in the near-field is studied by using the angular spectrum method of an electromagnetic beam. Physical images of the longitudinal components of evanescent waves are illustrated and compared with those of the transverse components from the vectorial structure. Our results indicate that the relative weight integrated over the transverse plane of the evanescent wave depends strongly on the number of the polarization topological charges. The shapes of the intensity profiles of the longitudinal components are different from those of the transverse components, and it can be manipulated by changing the initial SoP of the field cross-section. The longitudinal component of evanescent wave dominates the near-field region. In addition, it also leads to three-dimensional shape variations of the optical field and the optical spin angular momentum flux density distributions. (paper)

  18. On the Structure of Holographic Polymer-dispersed Polyethylene Glycol

    International Nuclear Information System (INIS)

    Birnkrant, M.; McWilliams, H.; Li, C.; Natarajan, L.; Tondiglia, V.; Sutherland, R.; Lloyd, P.; Bunning, T.

    2006-01-01

    Holographic polymerization (H-P) has been used to fabricate polymer-dispersed liquid crystals and pattern inert nanoparticles. In this article, one-dimensional grating structures of Norland resin and polyethylene glycol (PEG) were achieved using the H-P technique. Both reflection and transmission grating structures were fabricated. The optical properties of the reflection grating structures (also known as Bragg reflectors, BRs) are thermosensitive, which is attributed to the formation and crystallization of PEG crystals. The thermal switching temperature of the BR can be tuned by using different molecular weight PEG samples. The hierarchical structure and morphology of the BR were studied using synchrotron X-ray, polarized light microscopy and transmission electron microscopy. PEG crystals were found to be confined in ∼60 nm thick layers in the BR. Upon crystallization, the PEG lamellae were parallel to the BR surfaces and PEG chains were parallel to the BR normal, resembling the confined crystallization behavior of polyethylene oxide (PEO) in PEO-block-polystyrene (PEO-b-PS) block copolymers. This observation suggests that the tethering effect in the block copolymer systems does not play a major role in PEG chain orientation in the confined nanoenvironment

  19. Fabrication of the polarization independent spectral beam combining grating

    Science.gov (United States)

    Liu, Quan; Jin, Yunxia; Wu, Jianhong; Guo, Peiliang

    2016-03-01

    Owing to damage, thermal issues, and nonlinear optical effects, the output power of fiber laser has been proven to be limited. Beam combining techniques are the attractive solutions to achieve high-power high-brightness fiber laser output. The spectral beam combining (SBC) is a promising method to achieve high average power output without influencing the beam quality. A polarization independent spectral beam combining grating is one of the key elements in the SBC. In this paper the diffraction efficiency of the grating is investigated by rigorous coupled-wave analysis (RCWA). The theoretical -1st order diffraction efficiency of the grating is more than 95% from 1010nm to 1080nm for both TE and TM polarizations. The fabrication tolerance is analyzed. The polarization independent spectral beam combining grating with the period of 1.04μm has been fabricated by holographic lithography - ion beam etching, which are within the fabrication tolerance.

  20. A holographic bound for D3-brane

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, Davood; Myrzakul, Aizhan; Myrzakulov, Ratbay [Eurasian National University, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan); Eurasian National University, Department of General Theoretical Physics, Astana (Kazakhstan); Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Bahamonde, Sebastian [University College London, Department of Mathematics, London (United Kingdom)

    2017-06-15

    In this paper, we will regularize the holographic entanglement entropy, holographic complexity and fidelity susceptibility for a configuration of D3-branes. We will also study the regularization of the holographic complexity from the action for a configuration of D3-branes. It will be demonstrated that for a spherical shell of D3-branes the regularized holographic complexity is always greater than or equal to the regularized fidelity susceptibility. Furthermore, we will also demonstrate that the regularized holographic complexity is related to the regularized holographic entanglement entropy for this system. Thus, we will obtain a holographic bound involving regularized holographic complexity, regularized holographic entanglement entropy and regularized fidelity susceptibility of a configuration of D3-brane. We will also discuss a bound for regularized holographic complexity from action, for a D3-brane configuration. (orig.)

  1. Holo-GPC: Holographic Generalized Phase Contrast

    DEFF Research Database (Denmark)

    Bañas, Andrew; Glückstad, Jesper

    2017-01-01

    Light shaping methods based on spatial phase-only modulation can be classified depending on whether they distribute multiple beams or shape the individual beams. Diffractive optics or holography can be classified as the former, as it spatially distributes a plurality of focal spots over a working...... of GPC in forming well-defined speckle-free shapes that can be distributed over an extended 3D volume through holographic means. The combined strengths of the two photon-efficient phase-only light shaping modalities open new possibilities for contemporary laser sculpting applications....

  2. In vivo imaging of human oral hard and soft tissues by polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Walther, Julia; Golde, Jonas; Kirsten, Lars; Tetschke, Florian; Hempel, Franz; Rosenauer, Tobias; Hannig, Christian; Koch, Edmund

    2017-12-01

    Since optical coherence tomography (OCT) provides three-dimensional high-resolution images of biological tissue, the benefit of polarization contrast in the field of dentistry is highlighted in this study. Polarization-sensitive OCT (PS OCT) with phase-sensitive recording is used for imaging dental and mucosal tissues in the human oral cavity in vivo. An enhanced polarization contrast of oral structures is reached by analyzing the signals of the co- and crosspolarized channels of the swept source PS OCT system quantitatively with respect to reflectivity, retardation, optic axis orientation, and depolarization. The calculation of these polarization parameters enables a high tissue-specific contrast imaging for the detailed physical interpretation of human oral hard and soft tissues. For the proof-of-principle, imaging of composite restorations and mineralization defects at premolars as well as gingival, lingual, and labial oral mucosa was performed in vivo within the anterior oral cavity. The achieved contrast-enhanced results of the investigated human oral tissues by means of polarization-sensitive imaging are evaluated by the comparison with conventional intensity-based OCT.

  3. Future of photorefractive based holographic 3D display

    Science.gov (United States)

    Blanche, P.-A.; Bablumian, A.; Voorakaranam, R.; Christenson, C.; Lemieux, D.; Thomas, J.; Norwood, R. A.; Yamamoto, M.; Peyghambarian, N.

    2010-02-01

    The very first demonstration of our refreshable holographic display based on photorefractive polymer was published in Nature early 20081. Based on the unique properties of a new organic photorefractive material and the holographic stereography technique, this display addressed a gap between large static holograms printed in permanent media (photopolymers) and small real time holographic systems like the MIT holovideo. Applications range from medical imaging to refreshable maps and advertisement. Here we are presenting several technical solutions for improving the performance parameters of the initial display from an optical point of view. Full color holograms can be generated thanks to angular multiplexing, the recording time can be reduced from minutes to seconds with a pulsed laser, and full parallax hologram can be recorded in a reasonable time thanks to parallel writing. We also discuss the future of such a display and the possibility of video rate.

  4. Environmental stability study of holographic solar spectrum splitting materials

    Science.gov (United States)

    Chrysler, Benjamin D.; Ayala Pelaez, Silvana; Wu, Yuechen; Vorndran, Shelby D.; Kostuk, Raymond K.

    2016-09-01

    In this study the impact of outdoor temperature variations and solar illumination exposure on spectral filter material and holographic optical elements is examined. Although holographic components have been shown to be useful for solar spectrum splitting designs, relatively little quantitative data exist to demonstrate the extent to which these materials can withstand outdoor conditions. As researchers seek to investigate practical spectrum splitting designs, the environmental stability of holographic materials should be considered as an important factor. In the experiment presented, two holographic materials, Covestro Bayfol HX photopolymer and dichromated gelatin, and 3M reflective polymer filter materials are exposed to outdoor conditions for a period of several months. The environmental effect on absorption, spectral and angular bandwidth, peak efficiency, and Bragg matching conditions for the holograms are examined. Spectral bandwidth and transmittance of the 3M reflective filter material are also monitored. Holographic gratings are recorded, measured, and mounted on glass substrates and then sealed with a glass cover plate. The test samples are then mounted on a photovoltaic panel to simulate realistic temperature conditions and placed at an outdoor test facility in Tucson, Arizona. A duplicate set of holograms and 3M filter material is stored as a control group and periodically compared over the test period.

  5. High-contrast fluorescence imaging based on the polarization dependence of the fluorescence enhancement using an optical interference mirror slide.

    Science.gov (United States)

    Yasuda, Mitsuru; Akimoto, Takuo

    2015-01-01

    High-contrast fluorescence imaging using an optical interference mirror (OIM) slide that enhances the fluorescence from a fluorophore located on top of the OIM surface is reported. To enhance the fluorescence and reduce the background light of the OIM, transverse-electric-polarized excitation light was used as incident light, and the transverse-magnetic-polarized fluorescence signal was detected. As a result, an approximate 100-fold improvement in the signal-to-noise ratio was achieved through a 13-fold enhancement of the fluorescence signal and an 8-fold reduction of the background light.

  6. Polarization Control with Plasmonic Antenna Tips: A Universal Approach to Optical Nanocrystallography and Vector-Field Imaging

    Science.gov (United States)

    Park, Kyoung-Duck; Raschke, Markus B.

    2018-05-01

    Controlling the propagation and polarization vectors in linear and nonlinear optical spectroscopy enables to probe the anisotropy of optical responses providing structural symmetry selective contrast in optical imaging. Here we present a novel tilted antenna-tip approach to control the optical vector-field by breaking the axial symmetry of the nano-probe in tip-enhanced near-field microscopy. This gives rise to a localized plasmonic antenna effect with significantly enhanced optical field vectors with control of both \\textit{in-plane} and \\textit{out-of-plane} components. We use the resulting vector-field specificity in the symmetry selective nonlinear optical response of second-harmonic generation (SHG) for a generalized approach to optical nano-crystallography and -imaging. In tip-enhanced SHG imaging of monolayer MoS$_2$ films and single-crystalline ferroelectric YMnO$_3$, we reveal nano-crystallographic details of domain boundaries and domain topology with enhanced sensitivity and nanoscale spatial resolution. The approach is applicable to any anisotropic linear and nonlinear optical response, and provides for optical nano-crystallographic imaging of molecular or quantum materials.

  7. Holographic effective field theories

    Energy Technology Data Exchange (ETDEWEB)

    Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei' , Università di Padova,and INFN - Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Zaffaroni, Alberto [Dipartimento di Fisica, Università di Milano-Bicocca,and INFN - Sezione di Milano-Bicocca, I-20126 Milano (Italy)

    2016-06-28

    We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.

  8. Holographic twin Higgs model.

    Science.gov (United States)

    Geller, Michael; Telem, Ofri

    2015-05-15

    We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider.

  9. Holographic Twin Higgs Model

    Science.gov (United States)

    Geller, Michael; Telem, Ofri

    2015-05-01

    We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at mKK , naturally allowing for mKK beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider.

  10. Holographic magnetisation density waves

    Energy Technology Data Exchange (ETDEWEB)

    Donos, Aristomenis [Centre for Particle Theory and Department of Mathematical Sciences, Durham University,Stockton Road, Durham, DH1 3LE (United Kingdom); Pantelidou, Christiana [Departament de Fisica Quantica i Astrofisica & Institut de Ciencies del Cosmos (ICC),Universitat de Barcelona,Marti i Franques 1, 08028 Barcelona (Spain)

    2016-10-10

    We numerically construct asymptotically AdS black brane solutions of D=4 Einstein theory coupled to a scalar and two U(1) gauge fields. The solutions are holographically dual to d=3 CFTs in a constant external magnetic field along one of the U(1)’s. Below a critical temperature the system’s magnetisation density becomes inhomogeneous, leading to spontaneous formation of current density waves. We find that the transition can be of second order and that the solutions which minimise the free energy locally in the parameter space of solutions have averaged stressed tensor of a perfect fluid.

  11. Phases of Holographic QCD

    International Nuclear Information System (INIS)

    Lippert, Matthew

    2009-01-01

    We investigated the Sakai-Sugimoto model of large N QCD at nonzero temperature and baryon chemical potential and in the presence of background electric and magnetic fields. We studied the holographic representation of baryons and the deconfinement, chiral-symmetry breaking, and nuclear matter phase transitions. In a background electric field, chiral-symmetry breaking corresponds to an insulator-conductor transition. A magnetic field both catalyzes chiral-symmetry breaking and generates, in the confined phase, a pseudo-scalar gradient or, in the deconfined phase, an axial current. The resulting phase diagram is in qualitative agreement with studies of hot, dense QCD.

  12. Rapid Multiwaveband Polarization Variability in the Quasar PKS 0420-014: Optical Emission from the Compact Radio Jet

    Science.gov (United States)

    D'Arcangelo, Francesca D.; Marscher, Alan P.; Jorstad, Svetlana G.; Smith, Paul S.; Larionov, Valeri M.; Hagen-Thorn, Vladimir A.; Kopatskaya, Eugenia N.; Williams, G. Grant; Gear, Walter K.

    2007-04-01

    An 11 day monitoring campaign in late 2005 reveals clear correlation in polarization between the optical emission and the region of the intensity peak (the ``pseudocore'') at the upstream end of the jet in 43 GHz VLBA (Very Long Baseline Array) images in the highly variable quasar PKS 0420-014. The electric-vector position angle (EVPA) of the pseudocore rotated by about 80° in four VLBA observations over a period of 9 days, matching the trend of the optical EVPA. In addition, the 43 GHz EVPAs agree well with the optical values when we correct the former for Faraday rotation. Fluctuations in the polarization at both wave bands are consistent with the variable emission arising from a standing conical shock wave that compresses magnetically turbulent plasma in the ambient jet. The volume of the variable component is the same at both wave bands, although only ~20% of the total 43 GHz emission arises from this site. The remainder of the 43 GHz flux density must originate in a separate region with very low polarization. If 0420-014 is a typical case, the nonthermal optical emission from blazars originates primarily in and near the pseudocore rather than closer to the central engine where the flow collimates and accelerates.

  13. Cellular Dynamics Revealed by Digital Holographic Microscopy☆

    KAUST Repository

    Marquet, P.; Depeursinge, Christian; Jourdain, P.

    2016-01-01

    Digital holographic microscopy (DHM) is a new optical method that provides, without the use of any contrast agent, real-time, three-dimensional images of transparent living cells, with an axial sensitivity of a few tens of nanometers. They result from the hologram numerical reconstruction process, which permits a sub wavelength calculation of the phase shift, produced on the transmitted wave front, by the optically probed cells, namely the quantitative phase signal (QPS). Specifically, in addition to measurements of cellular surface morphometry and intracellular refractive index (RI), various biophysical cellular parameters including dry mass, absolute volume, membrane fluctuations at the nanoscale and biomechanical properties, transmembrane water permeability as swell as current, can be derived from the QPS. This article presents how quantitative phase DHM (QP-DHM) can explored cell dynamics at the nanoscale with a special attention to both the study of neuronal dynamics and the optical resolution of local neuronal network.

  14. Cellular Dynamics Revealed by Digital Holographic Microscopy☆

    KAUST Repository

    Marquet, P.

    2016-11-22

    Digital holographic microscopy (DHM) is a new optical method that provides, without the use of any contrast agent, real-time, three-dimensional images of transparent living cells, with an axial sensitivity of a few tens of nanometers. They result from the hologram numerical reconstruction process, which permits a sub wavelength calculation of the phase shift, produced on the transmitted wave front, by the optically probed cells, namely the quantitative phase signal (QPS). Specifically, in addition to measurements of cellular surface morphometry and intracellular refractive index (RI), various biophysical cellular parameters including dry mass, absolute volume, membrane fluctuations at the nanoscale and biomechanical properties, transmembrane water permeability as swell as current, can be derived from the QPS. This article presents how quantitative phase DHM (QP-DHM) can explored cell dynamics at the nanoscale with a special attention to both the study of neuronal dynamics and the optical resolution of local neuronal network.

  15. Digital Holographic Microscopy Principles, Techniques, and Applications

    CERN Document Server

    Kim, Myung K

    2011-01-01

    Digital holography is an emerging field of new paradigm in general imaging applications. By replacing the photochemical procedures with electronic imaging and having a direct numerical access to the complex optical field, a wide range of new imaging capabilities become available, many of them difficult or infeasible in conventional holography. An increasing number of researchers—not only in optical physics and optical engineering, but also in diverse applications areas such as microbiology, medicine, marine science, particle analysis, microelectromechanics, and metrology—are realizing and exploiting the new capabilities of digital holography. Digital Holographic Microscopy: Principles, Techniques, and Applications, by Dr. Myung K. Kim, is intended to provide a brief but consistent introduction to the principles of digital holography as well as to give an organized overview of the large number of techniques and applications being developed. This will also shed some light on the range of possibilities for f...

  16. Effect of birefringence of lens material on polarization status and optical imaging characteristics

    Science.gov (United States)

    Kim, Wan-Chin; Park, No-Cheol

    2018-04-01

    In most cases of molding with glass or optical polymers, it is expected that there will be birefringence caused by the internal mechanical stresses remaining in the molding material. The distribution of the residual stress can be annealed by slow cooling, but this approach is disadvantageous with respect to the shape accuracy and manufacturing time. In this study, we propose an analytical model to calculate the diffracted field near the focal plane by considering two primary parameters, the orientation angle of the fast axis and the path difference. In order to verify the reliability of the analytical model, we compared the measured beam spot of the F-theta lens of the laser scanning unit (LSU) with the analytical result. In addition, we analyzed the calculated result from the perspective of the polarization status in the exit pupil. The proposed analysis method can be applied to enhance the image quality for cases in which birefringence occurs in a lens material by suitably modeling the amplitude and phase of the incident light flux.

  17. Screening-induced surface polar optical phonon scattering in dual-gated graphene field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Bo, E-mail: hubo2011@semi.ac.cn

    2015-03-15

    The effect of surface polar optical phonons (SOs) from the dielectric layers on electron mobility in dual-gated graphene field effect transistors (GFETs) is studied theoretically. By taking into account SO scattering of electron as a main scattering mechanism, the electron mobility is calculated by the iterative solution of Boltzmann transport equation. In treating scattering with the SO modes, the dynamic dielectric screening is included and compared to the static dielectric screening and the dielectric screening in the static limit. It is found that the dynamic dielectric screening effect plays an important role in the range of low net carrier density. More importantly, in-plane acoustic phonon scattering and charged impurity scattering are also included in the total mobility for SiO{sub 2}-supported GFETs with various high-κ top-gate dielectric layers considered. The calculated total mobility results suggest both Al{sub 2}O{sub 3} and AlN are the promising candidate dielectric layers for the enhancement in room temperature mobility of graphene in the future.

  18. Estimating the Relative Water Content of Single Leaves from Optical Polarization Measurements

    Science.gov (United States)

    Vanderbilt, Vern; Daughtry, Craig; Dahlgren, Robert

    2016-01-01

    Remotely sensing the water status of plants and the water content of canopies remain long-term goals of remote sensing research. For monitoring canopy water status, existing approaches such as the Crop Water Stress Index and the Equivalent Water Thickness have limitations. The CWSI does not work well in humid regions, requires estimates of the vapor pressure deficit near the canopy during the remote sensing over-flight and, once stomata close, provides little information regarding the canopy water status. The EWI is based upon the physics of water-light interaction, not plant physiology. In this research, we applied optical polarization techniques to monitor the VISNIR light reflected from the leaf interior, R, as well as the leaf transmittance, T, as the relative water content (RWC) of corn (Zea mays) leaves decreased. Our results show that R and T both changed nonlinearly as each leaf dried, R increasing and T decreasing. Our results tie changes in the VISNIR R and T to leaf physiological changes linking the light scattered out of the drying leaf interior to its relative water content and to changes in leaf cellular structure and pigments. Our results suggest remotely sensing the physiological water status of a single leaf and perhaps of a plant canopy might be possible in the future. However, using our approach to estimate the water status of a leaf does not appear possible at present, because our results display too much variability that we do not yet understand.

  19. Real-Time Observation of Carbon Nanotube Etching Process Using Polarized Optical Microscope.

    Science.gov (United States)

    Zhao, Qiuchen; Yao, Fengrui; Wang, Zequn; Deng, Shibin; Tong, Lianming; Liu, Kaihui; Zhang, Jin

    2017-08-01

    Controllable synthesis of carbon nanotubes (CNTs) is of great importance in its further application, which attracts broad attention. As growth and etching are the two sides in the process of material crystallography and the control of the competition between them forms the foundation for modern technology of materials design and manufacture, the understanding on etching process of carbon nanotubes is still very unclear because technically it is of great challenge to characterize the dynamics in such small one-dimensional (1D) scale. Here the real-time investigation on the etching process of CNTs is reported, by the hot-wall chemical reactor equipped with a polarized optical microscope. It is discovered that the CNT etching behavior in air is totally of random, including the etching sites, termination sites, and structure dependence. Combining with the dynamic simulation, it is revealed that the random behavior reflects the unique "self-termination" phenomenon. A structure-independent etching propagation barrier of 2.4 eV is also obtained, which indicates that the etching propagation process still follows the conventional Kinetic Wulff construction theory. The results represent the new knowledge on the etching process in carbon nanotube and can contribute to its selective enrichment. Furthermore, the "self-termination" phenomenon may be a universal behavior in 1D process. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Investigation in clinical potential of polarization sensitive optical coherence tomography in laryngeal tumor model study

    Science.gov (United States)

    Zhou, Xin; Oak, Chulho; Ahn, Yeh-Chan; Kim, Sung Won; Tang, Shuo

    2018-02-01

    Polarization-sensitive optical coherence tomography (PS-OCT) is capable of measuring tissue birefringence. It has been widely applied to access the birefringence in tissues such as skin and cartilage. The vocal cord tissue consists of three anatomical layers from the surface to deep inside, the epithelium that contains almost no collagen, the lamina propria that is composed with abundant collagen, and the vocalis muscle layer. Due to the variation in the organization of collagen fibers, the different tissue layers show different tissue birefringence, which can be evaluated by PS-OCT phase retardation measurement. Furthermore, collagen fibers in healthy connective tissues are usually well organized, which provides relatively high birefringence. When the collagen organization is destroyed by diseases such as tumor, the birefringence of the tissue will decrease. In this study, a rabbit laryngeal tumor model with different stages of tumor progression is investigated ex-vivo by PS-OCT. The PS-OCT images show a gradual decrease in birefringence from normal tissue to severe tumor tissue. A phase retardation slope-based analysis is conducted to distinguish the epithelium, lamina propria, and muscle layers, respectively. The phase retardation slope quantifies the birefringence in different layers. The quantitative study provides a more detailed comparison among different stages of the rabbit laryngeal tumor model. The PS-OCT result is validated by the corresponding histology images of the same samples.