Abstract: An optical modulation/multiplexing circuit can fabricate a plurality of nonlinear optical waveguide devices and silica optical waveguides through a small number of processes, and achieve the simplification of the fabrication process and stabilization of the operation by hybrid integration with reduced connection loss. It employs lithium niobate domain inversion optical waveguides as nonlinear optical switches, and implements functions necessary for modulation and multiplexing such as input, splitting, multiplexing and timing adjustment of optical modulation signals and an optical clock signal by connecting glass waveguides to the input and output terminals of the domain inversion optical waveguides. Nonlinear optical media generate a second harmonic light beam of the optical clock signal, and at the same time produces a light beam with a frequency corresponding to the difference frequency of the two high frequency signals, the second harmonic light beam and the signal pulses.

Abstract: An ND filter includes a substrate formed in a plastic sheet and a deposited film formed on a surface of the substrate. The plastic sheet has at least 120° C. of a glass transition temperature. In producing the ND filter, the deposited film is formed on the surface of the substrate at a temperature below the glass transition temperature of the plastic sheet to suppress deformation due to expansion and contraction and to prevent the plastic sheet from wrinkling.

Abstract: Electromagnetic waves in wide frequency ranges up to photonics have been used for applications to time-domain imaging (TDI). Realistic time domain imaging requires a rapid optical delay line on the order of 100 ps with sampling rate at least 100 Hz. Present available optical time delay systems suffer either from low sampling rate or low time delay length, deviating from ideal requirements. The purpose of this invention is to introduce a miniature and rapid scanning optical delay line based on micro-opto-electro-mechanical system (MOEMS) technology to improve the data acquisition in time domain imaging, capable of sampling rate beyond 100 Hz and time delays beyond the 100 ps.

Abstract: An image display device comprising a holographic screen and an image projection device for projecting an image beam onto the holographic screen at an upward or downward angle is provided, wherein a forward view color difference &Dgr;u′v′ between a chromaticity value (u′, v′) at the center of the holographic screen when a white image is projected onto the holographic screen by the image projection device and a standard chromaticity value (u′o, v′o) is 0.04 or less when the projection angle of the image beam onto the center of the holographic screen is set to any angle within a specified projection angle range of 20 to 45°, whereby a image display device and holographic screen can be provided wherein the range of the projection angle of the image beam, in which an image with excellent color reproducibility can be displayed, is wide.

Abstract: A system for recording and reading out holograms in a storage medium including a pattern encoder, a first fourier transform lens with a focal length f1, a second fourier transform lens with a focal length f2, a detector array, and a first and second prism. The first prism is located between the pattern encoder and the first fourier transform lens, wherein the optical length between the pattern encoder and the first fourier transform lens through the first prism is equal to a back focal length BFL1. The second prism located between the second fourier transform lens f2 and the detector array, wherein the optical path length between the second fourier transform lens and the detector array through the second prism is equal to a back focal length BFL2.

Abstract: The invention relates to an optical component (1) consisting of a base unit (3) which supports a substrate (5) with a substrate region (7) that encompasses an optically functional surface, and a coating (9) which covers the substrate region (7) and at least part of the base unit (3). The substrate region (7) and a reference point (13) in the base unit (3) are oriented relative to each other in predefined fashion. The optical component (1) is produced by assembling the base unit (3) and the substrate (5) prior to the coating process, preferably by means of an assembly device (17). The assembled component is subsequently coated by employing a vacuum coating technique.

Abstract: Devices and methods are provided for a re-configurable optical add/drop multiplexer (ROADM) having a static circulator, a selectable grating and a reversible circulator. The use of a reversible circulator in a known optical drop multiplexer configuration allows the selectable grating to be used for selecting both the add-wavelength and the drop-wavelength while maintaining an East/West architectural split to allow for SONET compliant maintenance. This invention provides a cost-effective enhancement to a duplex reflective wavelength selective ROADM.

Abstract: The present invention provides a color filter which is more durable than a dye-type color filter and also has green pixel portions which exhibit a bright green color having a strong yellowish tinge when used in a liquid crystal display device using a three-band lamp having a main emission line of green light of about 545 nm as a light source, thus enabling the liquid crystal display device to display bright images even when using a backlighting light source having a low intensity. This color filter comprises green pixel portions which (1) contain a halogenated metal phthalocyanine dye wherein 8 to 16 halogen atoms are bonded to benzene rings in one phthalocyanine molecule, and (2) exhibit maximum transmittance at a wavelength within a range from 520 nm to 590 nm with respect to the transmission spectra of the entire range of visible light.

Abstract: The present invention relates to an optical signal processor which can multiplex or demultiplex multiwavelength signal light. The optical signal processor includes an optical input/output capability, a first optical system, a wavelength branching capability, a second optical system, and a reflecting capability.

Abstract: According to one aspect a method for manufacturing a holographic storage medium includes providing one or more data masks with data to be recorded, illuminating the one or more data masks onto the medium with a plane wave object beam from a laser light source operating at a record wavelength, propagating a reference beam at an incident angle to the medium to record the one or more data masks on the medium, and altering the incident angle of the reference beam for each of the one or more data masks, wherein each of the one or more data masks recorded on said medium can be read bit by bit using a laser light source operating in a readout range of wavelengths different from the record wavelength.

Abstract: Invisible different monochromatic images are inscribed in a diffractive optical element. Each of the images appears when a specific light source is on and image disappears when the specific light is off. The light sources for the different monochromatic images are spaced at different positions with respect to the diffractive optical element. A dynamic image is produced by time-varying and electronically controlling the intensity and on/off of the different light sources.

Abstract: An optical pickup unit includes a light source of semiconductor laser chips of different light-emission wavelengths; a plurality of holograms placed between the light source and an optical recording medium, the holograms including at least one non-polarization hologram having a substantially uniform diffraction efficiency irrespective of the direction of polarization of incident light and at least one polarization hologram having a diffraction efficiency varying depending on the direction of polarization of incident light; and a wave plate provided between the optical recording medium and the polarization hologram. The returning beam of a light beam emitted from a selected one of the semiconductor laser chips is diffracted by the corresponding one of said holograms to be received by a light-receiving element. The wave plate turns the direction of polarization of the returning beam to a different direction from that of the emitted light beam.

Abstract: A tunable optical filter including at least one deformable membrane actuator. The actuator may include an array of a thousand or millions of individual actuator cells for strength and mechanical robustness. The deformable membrane actuator including a first primary substrate having a first optical portion, an electrically conductive and deformable membrane, an electrically conductive primary substrate electrode and a membrane support structure. The substrate electrode and the membrane support structure are disposed on or adjacent to the first primary substrate, the deformable membrane being supported by the membrane support structure, and a second substrate having a second optical portion. The second substrate is supported by a load support structure disposed on one surface of the deformable membrane and is located a distance from the first substrate.

Abstract: The present invention relates to a device for homogenizing the spatial intensity distribution of a spatially coherent radiation beam. The device includes a grating arranged in the propagation path of a spatially coherent radiation beam for diffracting the coherent beam and thus decreasing the coherence length of a diffracted radiation beam in a direction orthogonal to the propagation direction of the radiation beam relative to the width of the radiation beam in the orthogonal direction; and a radiation splitting and directing arrangement arranged in the propagation path of the diffracted radiation beam for splitting the diffracted radiation beam into spatially separated portions and for superimposing the spatially separated portions to form a radiation beam having a homogenized spatial intensity distribution.

Abstract: An objective lens unit for an optical pickup used for recording and/or reproducing information signals from an optical disc. The objective lens unit includes a resin layer (21) having, sequentially from an object side, a first surface S1 as an aspherical surface and a second surface S2 as an aspherical surface, at least one of the first surface and the second surface including a diffractive surface, and a lens of glass (22) having the second surface S2 as an aspherical surface and a third surface S3 as an aspherical surface. The lens unit is corrected for the chromatic aberration on an image surface on the optical axis with respect to the light of a reference wavelength not larger than 420 nm within several nm of the reference wavelength, with the numerical aperture of the lens unit being not less than 0.8. This objective lens unit is able to converge the laser light close to the limit of diffraction on the image surface.

Abstract: An image display device including a polarization selective holographic optical device for diffracting illuminating light, and a reflection type spatial optical modulator for modulating the state of polarization of the illuminating light diffracted by the polarization selective holographic optical device is disclosed. The device includes a plurality of each of two areas of respectively different incidence polarization orientation dependencies of the refractive index, with the layers being layered sequentially alternately. An image display apparatus including the above image display device, a light source, an illuminating optical system and a projection optical system is also disclosed. With the present optical display device and optical display apparatus, the utilization efficiency of the illuminating light may be improved, while the device and the apparatus may be reduced in size and production cost, as uniformity and high contrast of the image displayed are achieved simultaneously.

Abstract: A computer-generated hologram fabrication process that enables a plurality of original images to be observed with master-slave relations Original images 11, 12, a recording surface 20 and reference light R are defined on a computer, and a number of point light sources P11-1, . . . , P12-1, . . . as samples are defined on each original image. Given angles of spreading of object light beams emitted from individual point light sources are defined, and areas on the recording surface 20, at which object light beams emitted from point light sources defined on each original image 11, 12 with the thus limited given angles of spreading arrive, are determined as recording areas &agr;11 and &agr;12 corresponding to the original images 11 and 12. When there is an overlapping (hatched) portion in the recording areas, the overlapping portion is determined as a recording area corresponding to the master original image.

Abstract: An etalon has at least one transparent plate, wherein the transparent plate consists of lithium tantalate single crystal, an etalon has at least one transparent plate, wherein the transparent plate consists of lithium niobate single crystal and a method for producing an etalon, which includes at least growing a single crystal of lithium tantalate or lithium niobate by the Czochralski method, producing a transparent plate from the single crystal and producing an etalon from the transparent plate. There are provided etalons of thin type showing high thermal stability.

Abstract: The present invention is a phase-imaging technique by digital holography that eliminates the problem of 2&pgr;-ambiguity. The technique is based on a combination of two or more digital holograms generated using multiple wavelengths. For a two-wavelength experiment, the phase maps of two digital holograms of different wavelengths are subtracted which yields another phase map whose effective wavelength is inversely proportional to the difference of wavelengths. Using two holograms made with a 633 nm HeNe laser and a 532 nm doubled YAG laser an image was obtained that is a 3D reconstruction of a reflective surface with axial resolution of ˜10 nm over a range of −5 um, without any phase discontinuity over this range. The method can be extended to three wavelengths or more in order to reduce the effect of phase noise further.

Abstract: A grating that includes a multilayer structure that has alternating layers of materials, a plurality of grooves formed between a plurality of lands, wherein at least one structural parameter of the plurality of grooves and plurality of lands is formed randomly in the multilayer structure.