Abstract: A charge-transfer material enables patterning approach where the polarization angle in stand-alone films can be precisely defined at the single pixel level and reconfigured following initial alignment. This capability enables new routes for non-binary information storage, retrieval, and intrinsic encryption, and it suggests future technologies such as photonic chips that can be reconfigured using non-contact patterning.

Abstract: A holographic display panel comprises a plurality of display units, each display unit comprises at least two adjacent pixels, each pixel comprises: a plurality of sub-pixels; and a plurality of phase plates. Diffractive angles of light coming out of the phase plates corresponding to the sub-pixels in a same pixel are the same, a diffractive angle of first light coming out of the phase plates corresponding to a first pixel in one of the display units is different from a diffractive angle of second light coming out of the phase plates corresponding to a second pixel that is different from the first pixel but in the same display unit, and a reverse extension line of the first light and a reverse extension line of the second light intersect at an image plane position.

Abstract: A spatial light modulating panel using a transitive liquid crystal display panel and a three-dimensional display device using the same. A a spatial light modulator including a plurality of pixels arrayed in a matrix manner; and a liquid crystal layer configured to modulate phase of an incident light passing through the each pixel, respectively. The spatial light modulator and the 3D display using the same provides a thin flat type display system having an easy and simple structure and a low manufacturing cost.

Abstract: Provided are methods and systems for identification and analysis of materials and molecular structures. An apparatus for identification and analysis of materials and molecular structures may include a laser. The laser may, in turn, include an amplified spontaneous emission-suppressed single-frequency laser excitation source. The apparatus may further comprise a plurality of filters. The plurality of filters may include reflective volume holographic grating blocking filters. The apparatus may also comprise an optical unit and an optical spectrometer. The optical unit may be configured to deliver excitation energy to a sample substance and capture Raman signal scattering from the sample substance. The optical spectrometer may be disposed in a path of the Raman signal and configured to measure a spectrum of the Raman signal and generate a detection signal. Finally, the apparatus may comprise a processing unit configured to analyze the spectrum.

Abstract: The inventive concept relates to a beating signal monitoring module and a terahertz wave generation device and an optical signal monitoring device that including the beating signal monitoring module. The beating signal monitoring module includes a nonlinear unit generating an optical signal including a FWM light in response to a beating signal generated from a first light and a second light; a filter unit separating the FWM light from the optical signal and outputting the separated FWM light; and a monitoring unit monitoring the beating signal using the separated FWM light. The beating signal monitoring module and a terahertz wave generation device and an optical signal monitoring device that including the beating signal monitoring module can effectively monitor a beating signal being generated by two lasers using a Four Wave Mixing signal.

Abstract: Iterating an optical phase conjugation of ultrasonically-modulated diffuse light emitted by a scattering medium includes illuminating the scattering medium with a light beam from a coherent light source, modulating the diffuse light transmitted through the scattering medium with an ultrasonic wave focused on a region of interest within the scattering medium, fixing a hologram, retro-reflectively illuminating the scattering medium using a phase-conjugated copy of the diffuse light that was ultrasonically modulated, moving the ultrasonic focus, and iterating until light is focused on the final target.

Abstract: System and method for compensating distortions introduced by an optical channel and by at least one directly modulated transmitting laser that transmits a modulated optical signal that carries data to a receiving end over the optical channel.

Abstract: Devices and techniques for using four wave mixing in optical sensing of various materials, including isotopes, chemical and biological substances.

Abstract: This invention relates a method of six-dimensional optical multilayer storage using two-photon absorption writing, erasing and optical coherence tomography reading and the apparatus designed based on this method. The invented system stores data in three spatial dimensions plus three physical dimensions of wavelength, intensity and polarization. It has large storage capacity of over 32 Tbytes per DVD sized disk and ultrafast reading speed of over 25 Gbits/s with high signal-to-noise ratio of over 76 dB. The larger capacity of over 1 Pbyte per disk is potential. Furthermore, the invented system has relatively simple optical structure, easy light manipulation for addressing the storage cell and high compatibility with the CDs and DVDs. It is an actually practicable optical large capacity storage technology.

Abstract: A system and method for irradiating a medium including irradiating the medium with an electromagnetic wave which is scattered in the medium and modulated in frequency at a position in the medium; obtaining information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and a reference wave; and generating a phase conjugate wave, based on the obtained information, which irradiates the medium.

Abstract: The invention provides a process capable of fabricating a cholesteric liquid crystal medium having a volume hologram with efficiency yet without recourse to complicated steps such as an alignment step. This is achievable as follows. A volume hologram layer is formed on a substrate, and a cholesteric liquid crystal layer is then formed on another substrate. The volume hologram layer and the cholesteric liquid crystal layer are laminated together via a bonding layer. Further, a bonding for lamination onto an application member is formed on either the volume hologram layer side or the cholesteric liquid crystal layer side to obtain a cholesteric liquid crystal medium having a volume hologram.

Abstract: A Head Up Display can be utilized to find light from an energy source. The Head Up Display includes a first waveguide having a first input coupler and a first output coupler. The Head Up Display can also include a second waveguide having a second input coupler and a second output coupler. The first waveguide has a first major surface and the second waveguide has a second major surface, which are disposed approximately parallel to each other. The first waveguide and the second waveguide are positioned as a combiner and allowing viewing an outside feed and information from an image source. The first input coupler diffracts light in the first field of view into the first waveguide and light in a second field of view reaches the second input coupler and is diffracted into the second waveguide.

Abstract: Devices and methods for recording and reproducing a holographic 3D image are provided. The devices for recording the holographic 3D image comprising: a laser generation unit for emitting a laser beam; a beam splitter unit configured to receive the laser beam from the laser generation unit and split the laser beam into a reference beam and an object beam directed to an object to be photographed; a photorefractive crystal configured to receive the reference beam from the beam splitter and the object beam diffused from the object to form a holographic 3D image; and a rotation unit configured to rotate the photorefractive crystal once every time one holographic 3D image is recorded. The holographic 3D image can be recorded and reproduced by the rotate the photorefractive crystal in light paths of recording and reproduction light beams, respectively.

Abstract: A cooling device which prevents ambient persons from being exposed to an unpleasant feeling as much as possible by properly controlling an exhausting direction of the air which is used for cooling and exhausted from a chassis and an image projection apparatus having the cooling device are obtained. The cooing device cools first and second members to be cooled provided in the chassis, has first and second exhaust fans for guiding winds which have cooled the respective first and second members to an outside of the chassis, and is characterized in that the first and second exhaust fans are arranged so as to face the same surface of the chassis and the winds exhausted from the first and second exhaust fans are mixed.

Abstract: There is provided a light source unit which includes a luminescent light source which receives excitation light so as to emit light of a predetermined wavelength band, excitation light sources which shine excitation light on to the luminescent light source, a reflection space having the luminescent light source in an interior thereof and an emission space which emits luminescent light source light emitted from the reflection space from an emission port whose area is made smaller than the area of the luminescent light source and a projector which employs the light source unit.

Abstract: An optical material includes lithium tantalate, and a molar composition ratio of lithium oxide and tantalum oxide (Li2O/Ta2O5) in the lithium tantalate is in the range of 0.975 to 0.982. Since an optical material having a high refractive index is provided in an optical unit, at the same focal distance, a lens thickness can be significantly reduced. As a result, an optical electronic component and an optical electronic device including the optical material has a reduced size and thickness and is highly functional.

Abstract: An updateable system and method of recording a hologram on a media simultaneously reduces the writing time and increases persistence without sacrificing diffraction efficiency. A voltage kick-off technique controls the bias electric field applied to a photorefractive polymer media in conjunction with the application of the writing beams and dark decay. Essentially the voltage kick-off technique applies a high electric field above the optimal field while the writing beams are on and reduces the electric field when the writing beams are off during dark decay. The voltage kick-off technique produced two separate unexpected results. First, when the writing beams are turned off and the electric field is lowered the diffraction efficiency continues to increase until it reaches a maximum efficiency that is within a few percent of that achieved by writing at the optimal field until steady-state is achieved.

Abstract: A method and system for bulk erasing in a holographic storage system is disclosed. The method may involve illuminating the entire volume storage region of a photorefractive crystal with a laser to achieve bulk erasure, or may involve selective erasure of a portion of a single written page. For bulk erasure of the entire photorefractive crystal the use of a separate laser or an incoherent light source is used.

Abstract: A method and device for re-writing data on a holographic storage device is disclosed. First and second electro-optic modulators may phase shift the reference and data beams used to store data on the photorefractive crystal. When the reference beam is shifted 180° out of phase with respect to the data beam, the photorefractive crystal is erased.

Abstract: A method is provided for monitoring degradation of a data storage medium. Multiple reactive elements are provided in the data storage medium. Properties of each one of these elements is determined, prior or subsequent to data being stored in the medium, to generate a baseline map of the medium. Updated properties of at least one of the elements are determined in order to generate an updated map of the medium. A determination can then be made as to whether degradation of the medium has occurred by comparing the baseline map to the updated map.

Abstract: A three-dimensional hologram image display apparatus displays a three-dimensional hologram image by use of computed interference fringe patterns. The three-dimensional hologram image display apparatus includes a light modulation device which has an electro-optical effect in which a refractive index is varied in accordance with an applied electric field intensity; and an electric field controller configured to record computed interference fringe patterns in the light modulation device by varying an electric field intensity applied to the light modulation device in accordance with the computed interference fringe patterns.

Abstract: An object of the present invention is to provide an electron microscope that employs a hologram of a diffraction pattern to reconstruct a microscopic image involving no imaging aberration due to image forming lenses, as well as a combined illumination lens used for such an electron microscope.

Abstract: Single crystals with low scattering, small refractive index differences and few small angle grain boundaries have a bi-directional scattering distribution function value (BSDF) of less than 1.5*10?6 or 5*10?7.

Abstract: An updateable system and method of recording a hologram on a media simultaneously reduces the writing time and increases persistence without sacrificing diffraction efficiency. A voltage kick-off technique controls the bias electric field applied to a photorefractive polymer media in conjunction with the application of the writing beams and dark decay. Essentially the voltage kick-off technique applies a high electric field above the optimal field while the writing beams are on and reduces the electric field when the writing beams are off during dark decay. The voltage kick-off technique produced two separate unexpected results. First, when the writing beams are turned off and the electric field is lowered the diffraction efficiency continues to increase until it reaches a maximum efficiency that is within a few percent of that achieved by writing at the optimal field until steady-state is achieved.

Abstract: The present invention provides a multi-channel tunable filter and methods for making such a filter. In one embodiment, the filter comprises a bank of gratings or a continuously varying filter frequency imprinted into a filter material, such as Lithium Niobate or glass or polymer. An optical read-head comprising a pair of lenses is configured to pass light from within an optical fiber carrying multiple wavelengths through an appropriate grating to extract or drop a specific wavelength. To ensure continuous data transmission, the filter is tuned to a wavelength by configuring the read-head to move in a hitless manner. In one embodiment, the gratings are recorded by the interference of two beams. A first plane wave reflects off a first mirror stack and a second plane wave reflects off a second mirror stack. In another embodiment, the gratings are recorded by a phase masking method.

Abstract: A diffractive optical element such as a diffuser, diffraction grating, and/or hologram, can be manufactured by using a surface relief pattern on a surface of a surface relief tool. A layer of curable material is physically contacted with the surface relief pattern on the surface of the surface relief tool to thereby imprint the pattern on a surface of the layer. Diffractive features are formed in the layer by propagating energy through the surface relief tool and into the layer such that refractive index variations corresponding to the pattern are created in the layer. The resultant product is a diffractive optical element comprising a layer of material having diffractive features formed by a predetermined pattern of refractive index variations. The diffractive features originate at an undulating boundary and extend only from one side of the boundary into the material. The undulating boundary has an undulating pattern that corresponds to the predetermined pattern of refractive index variations.

Abstract: A method for storing holographic data, said method comprising: step (A) providing an optically transparent substrate comprising a polymer composition and a light absorbing chromophore, said polymer composition comprising a continuous phase and a dispersed phase, said dispersed phase being less than about 200 nm in size; and step (B) irradiating a volume element of the optically transparent substrate with a holographic interference pattern, wherein the pattern has a first wavelength and an intensity both sufficient to cause a phase change in at least a portion of the dispersed phase within the volume element of the substrate to produce within the irradiated volume element refractive index variations corresponding to the holographic interference pattern, thereby producing an optically readable datum corresponding to the volume element.

Abstract: The present invention comprises an apparatus and method for recording information on a multi-layer diffractive optics memory to extend storage capacity. A composite mirror device comprises a plurality of sets of mirror elements. Each one of the mirror elements of the sets is configured to direct a reference beam to a point of the multi-layer memory at one of a plurality of angles. A plurality of planes is associated with the plurality of sets. There is one plane per set, each plane being defined for each of the sets of mirror elements so that the paths formed from the mirror elements of the set to the point lie in the plane. Each of the planes is separated from its neighbor by an angle selected to avoid crosstalk.

Abstract: A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.

Abstract: A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) or Micro-Electro-Mechanical Systems (MEMS) mirrors steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.

Abstract: The present invention provides a multi-channel tunable filter and methods for making such a filter. In one embodiment, the filter comprises a bank of gratings imprinted into a filter material, such as Lithium Niobate. In another embodiment, the filter comprises a bank of gratings imprinted on a thin-film filter. An optical read-head comprising a pair of lenses is configured to pass light from within an optical fiber carrying multiple wavelengths through an appropriate grating to extract or drop a specific wavelength. To ensure continuous data transmission, the filter is tuned to a wavelength by configuring the read-head to move in a hitless manner. In one embodiment, the gratings are recorded by the interference of two beams. A first plane wave reflects off a first mirror stack and a second plane wave reflects off a second mirror stack. In another embodiment, the gratings are recorded by a phase masking method.

Abstract: A wavelength multiplexed holographic system includes a wavelength tunable blue-violet laser and a controller for wavelength multiplexing. A method of holographic data recording includes providing a holographic medium, providing a tunable blue-violet laser for wavelength multiplexing, and tuning the laser wavelength to record a hologram at a set wavelength and recording holographic data at the set wavelength on the holographic medium. A method for retrieving holographic data includes providing a holographic medium, providing at least one tunable blue-violet laser, tuning the blue-violet laser to a set wavelength, and retrieving holographic data at the set wavelength.

Abstract: A holographic recording medium includes a transparent layer having a servo surface and a light incidence surface which face each other; a reflecting layer formed on the servo surface-side transparent layer; and a holographic recording layer formed on the light illuminating-side transparent layer. The transparent layer includes resin films laminated so that adjacent resin films differ in stretching direction by 90 degrees.

Abstract: The invention relates to an object of value with a security element having at least a first and a second liquid-crystalline material, the first material having thermochromic properties and the second material an optically variable effect.

Abstract: In one embodiment, holographic data storage medium includes a first thermoplastic substrate portion having a thickness less than approximately 2 millimeters and a second thermoplastic substrate portion having a thickness less than approximately 2 millimeters. A holographic recording material may be sandwiched between the first and second thermoplastic substrate portions. By making thermoplastic substrate portions sufficiently thin, edge wedge problems can be avoided.

Abstract: A holographic recording medium includes a transparent layer having a servo surface and a light incidence surface which face each other; a reflecting layer formed on the servo surface-side transparent layer; and a holographic recording layer formed on the light illuminating-side transparent layer. The transparent layer includes resin films laminated so that adjacent resin films differ in stretching direction by 90 degrees.

Abstract: A holographic memory system includes a light source for generating a reference beam having a wavelength; and a photodetecting device for selectively detecting a reconstructed signal beam corresponding to the reference beam. The photodetecting device includes a band-pass filter for transmitting light of a wavelength band including the wavelength of the reconstructed signal beam while blocking light having a wavelength deviating from the wavelength band; and a photodetecting unit for detecting the light transmitted through the band-pass filter.

Abstract: A recording material for holograms includes a metal oxide porous body with an oxygen donor substance in the pores. In addition, a method manufactures a recording material for holograms that include a metal oxide porous body with an oxygen donor substance in the pores. The method includes forming a metal oxide porous body from a metal oxide precursor, and supplying an oxygen donor substance to the pores of the metal oxide porous body.

Abstract: A phase volume hologram and a method for producing the phase volume hologram are described herein. The phase volume hologram is made by filling the microcavities of a porous transparent siliceous body with a polymerisable composition (e.g., liquid monomer or monomer/oligomer mixture). The filled siliceous body then has a hologram interference pattern recorded therein using a laser light that in conformity with the hologram interference pattern converts the polymerisable composition into a polymerized material (solid-phase polymer) and a non-polymerized material. In particular, the polymerized material has a volume fraction in the microcavities that is close to 1 in the vicinity of a maxima of the recorded interference pattern and close to 0 in the vicinity of a minima of the recorded interference pattern. Thereafter, the non-polymerized material is removed from the siliceous body which now resembles the phase volume hologram.

Abstract: The present invention discloses a recording medium comprising an improved doped Stoichiometric Lithium Niobate (SLN) crystal for high-speed holographic data storage. The improved doped SLN has an extremely high optical damage resistance of more than 145 kW/cm2 for power density of an incident laser beam along the c axis. The Recording time using the present improved doped SLN is advantageously very short and is about 1 second for a single hologram with a saturated diffraction efficiency of 28.7% at a recording laser beam density of 70 W/cm2. Reliable retrieval of a signal-image written at as low as 1 milliseconds has been performed in the Z-cut doped SLN. The present recording medium is an improved doped SLN of a Z-cut SLN crystal doped with Iron (Fe) and Terbium (Tb). The Terbium (Tb) content within the fluxed melts for growing the improved doped SLN ranges from 10 ppm to 140 ppm.

Abstract: A description is provided of an optical information recording and reproducing apparatus having a volume holographic memory. The apparatus is capable of recording an interference pattern in the volume holographic memory in high density and can be made small-sized.

Abstract: In a hologram recording method for forming a plurality of areas of a refractive index light interference pattern of a coherent signal light beam in accordance with information data within a recording medium having a shape of parallel flat plates, the signal light beam and the recording reference light beam cross each other within the recording medium, and a gate light beam having a second wavelength for revealing recording sensitivity of the recording medium is simultaneously irradiated to the recording medium so as to pass through a portion of the recording reference light beam and demarcate a volume smaller than that of this crossing portion.

Abstract: A holographic recording medium exhibiting a high recording sensitivity without execution of reduction treatment. A system records information on the holographic recording medium by using a gating light within a wavelength band causing less optical damage to the holographic recording medium. The holographic recording medium includes a single crystal of lithium niobate (LiNbO3) or lithium tantalate (LiTaO3) containing Mn as a dopant.

Abstract: A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) or Micro-Electro-Mechanical Systems (MEMS) mirrors steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.

Abstract: A ferroelectric material in which the refractive index change can be induced by irradiation with light at two different wavelengths without performing a reduction treatment or doping impurities. The ferroelectric material of the invention in which the refractive index change is induced by irradiation with light at two different wavelengths is a lithium tantalate single crystal with the composition of Li2O/(Li2O+Ta2O5)=0.4966 to 0.4995. Preferably, the ferroelectric material is a lithium tantalate single crystal with the composition of Li2O/(Li2O+Ta2O5)=0.4974 to 0.4989. Preferably, the infrared absorption coefficient in the [OH] stretching mode falls within a range of 0 cm−1 to 0.15 cm−1 (0 cm−1 and 0.15 cm−1 are included in the range).

Abstract: A phase volume hologram and a method for producing the phase volume hologram are described herein. The phase volume hologram is made by filling the microcavities of a porous transparent siliceous body with a polymerisable composition (e.g., liquid monomer or monomer/oligomer mixture). The filled siliceous body then has a hologram interference pattern recorded therein using a laser light that in conformity with the hologram interference pattern converts the polymerisable composition into a polymerized material (solid-phase polymer) and a non-polymerized material. In particular, the polymerized material has a volume fraction in the microcavities that is close to 1 in the vicinity of a maxima of the recorded interference pattern and close to 0 in the vicinity of a minima of the recorded interference pattern. Thereafter, the non-polymerized material is removed from the siliceous body which now resembles the phase volume hologram.

Abstract: A holographic information storage and retrieval system provides an all-optical reversible method to fix information in doped or undoped photorefractive materials. The fixed information is sufficiently stable to provide long term archival storage over a period of decades or more and can be read out non-destructively by a coherent reference beam. Holograms recorded in a photorefractive material are fixed when the material is irradiated with incoherent ultraviolet light. Hence, the holograms are preserved indefinitely against erasure by a coherent beam and against dissipation in dark storage. Holograms, which are fixed in the photorefractive material with incoherent ultraviolet light, are also erased with incoherent ultraviolet light, thus making the process reversible.

Abstract: A photorefractive material provides a high photosensitivity without reduction. The material comprises a single crystal of terbium (Tb)-doped niobate or tantalate. The single crystal is a single crystal of lithium niobate (LiNbO3) whose molar fraction of [Li2O]/([Li2O]+[Nb2O5]) lies in a range of 0.482 to 0.505, or a single crystal of lithium tantalate (LiTaO3) whose molar fraction of [Li2O]/([Li2O]+[Ta2O5]) lies in a range of 0.482 to 0.505. The amount of terbium added in the photorefractive material ranges from 10 weight ppm to 1000 weight ppm.

Abstract: Liquid crystal is filled between a pair of transparent plate electrodes, and a DC voltage is applied between the electrodes to align the liquid crystal molecules along the electric field. When light enters the liquid crystal cell, the alignment of the liquid crystal molecules deviates due to the electric field of the light. The change in the alignment of the liquid crystal molecules is detected by a change in the capacitance or in the electric resistance between the plate electrodes. A liquid crystal panel 35 constituted by a two-dimensional array of such liquid crystal cells is used as an image sensor, and the interference patterns of an object 38 are produced on and detected by the liquid crystal pattern 35 in real time. The detected interference patterns are recorded continuously, whereby a three-dimensional movie is recorded.

Abstract: A diffractive optical element such as a diffuser, diffraction grating, and/or hologram, can be manufactured by using a surface relief pattern on a surface of a surface relief tool. A layer of curable material is physically contacted with the surface relief pattern on the surface of the surface relief tool to thereby imprint the pattern on a surface of the layer. Diffractive features are formed in the layer by propagating energy through the surface relief tool and into the layer such that refractive index variations corresponding to the pattern are created in the layer. The resultant product is a diffractive optical element comprising a layer of material having diffractive features formed by a predetermined pattern of refractive index variations. The diffractive features originate at an undulating boundary and extend only from one side of the boundary into the material. The undulating boundary has an undulating pattern that corresponds to the predetermined pattern of refractive index variations.