Abstract: An apparatus for replicating holographically recorded data, comprising a holographic master media having holographically recorded data thereon; a holographic copy media; a light source for generating a master reference beam and a copy reference beam, coherent with the first object beam, the first master reference beam incident on the holographic master media, the holographic master media diffracting the master reference beam to provide a first object beam; the copy reference beam incident on the holographic copy media; and a first optical relay system, disposed between the holographic master media and the holographic copy media, for relaying the first object beam from the holographic master media to the holographic copy media, the holographic copy media recording an interference pattern between the first object beam and the copy reference beam, thereby replicating at least a portion of holographically recorded data.

Abstract: A method and an apparatus for recording at least two multiplexed holograms. Either an object beam or a reference beam is reflected from an aspherical reflecting surface. Either the reference beam impinging on a recording media at the selected storage location or the object beam impinging on the recording media at the selected storage location is rotated through a selected azimuthal angle about an axis that passes through a plane defined by the intersection of the object beam and the reference beam in the recording media, wherein an angle between the object beam and the reference beam impinging on the recording media is preserved.

Abstract: An apparatus for image acquisition of topological features of the surface of skin. The apparatus comprises a waveguide, having an entrance edge and top and bottom surfaces; a light source, configured to direct a light beam at the entrance edge of the waveguide; a skin contact layer, disposed at or near the top surface of the waveguides; a holographic optical element (HOE), disposed at the top or at the bottom surfaces of the waveguide, configured to diffract the light beam incident from the light source to the skin contact layer; a sensor array, configured to detect light reflected from the surface of skin in contact with skin contact layer; and means for compensating for changes in the Bragg matching condition of the HOE due to temperature.

Abstract: An apparatus for identifying fake fingerprints has electrodes disposed along a platen surface of a fingerprint scanner and whether or not the skin of one or more fingers presented to the surface are real and alive is determined in accordance with analysis of electrical signals received from the electrodes. Electronics of the apparatus determines one or more liveness parameter(s) in accordance with signals received from electrodes. Information from an image of the fingerprint may be used to select which electrode signals to use for liveness detection. To further confirm the presence of a live finger(s), additional liveness parameter(s) of the pulse and/or temperature may also be sensed. The skin may be one of in contact with the platen of the fingerprint scanner, separated from direct contact with the platen's electrodes by an insulating layer or a pad, or not in physical contact with the platen or a pad thereupon.

Abstract: The apparatus represents a device having one or two sensors for capturing a single image or two images having the subject's eyes, in which a dimension, such as the horizontal axis, with respect to pixels in the single image or two first images characterizing zero head tilt, and processors in one or more of a housing with the one or two sensors or in a computer system which receives the single image or two images. Such processors determine a head tilt angle between a virtual line extending between the two eyes of the subject in accordance with predefined features, such as pupil or iris center, in the single image or two images and the dimension characterizing zero head tilt, segment left and right iris images from the single image or two images, and rotate the segmented left and right iris image in accordance with the angle to substantially remove head tilt when present.

Abstract: An apparatus for replicating holographically recorded data, comprising a holographic master media having holographically recorded data thereon; a holographic copy media; a light source for generating a master reference beam and a copy reference beam, coherent with the first object beam, the first master reference beam incident on the holographic master media, the holographic master media diffracting the master reference beam to provide a first object beam; the copy reference beam incident on the holographic copy media; and a first optical relay system, disposed between the holographic master media and the holographic copy media, for relaying the first object beam from the holographic master media to the holographic copy media, the holographic copy media recording an interference pattern between the first object beam and the copy reference beam, thereby replicating at least a portion of holographically recorded data.

Abstract: An apparatus for replicating holographically recorded data, comprising a holographic master media having holographically recorded data thereon; a holographic copy media; a light source for generating a master reference beam and a copy reference beam, coherent with the first object beam, the first master reference beam incident on the holographic master media, the holographic master media diffracting the master reference beam to provide a first object beam; the copy reference beam incident on the holographic copy media; and a first optical relay system, disposed between the holographic master media and the holographic copy media, for relaying the first object beam from the holographic master media to the holographic copy media, the holographic copy media recording an interference pattern between the first object beam and the copy reference beam, thereby replicating at least a portion of holographically recorded data.

Abstract: An apparatus for image acquisition of topological features of the surface of skin. The apparatus comprises a waveguide, having an entrance edge and top and bottom surfaces; a light source, configured to direct a light beam at the entrance edge of the waveguide; a skin contact layer, disposed at or near the top surface of the waveguides; a holographic optical element (HOE), disposed at the top or at the bottom surfaces of the waveguide, configured to diffract the light beam incident from the light source to the skin contact layer; a sensor array, configured to detect light reflected from the surface of skin in contact with skin contact layer; and means for compensating for changes in the Bragg matching condition of the HOE due to temperature.

Abstract: Holographic data storage systems are fixed after exposure during which data in the form of holograms are stored at locations in the medium (4). Sufficient fixing energy in the form of light or other electromagnetic and thermal radiation is applied to the media (4) either by flooding the media, or to specific locations where the medium has been written. The energy is sufficient to expose the recorded medium (4) to prevent recording in the unused dynamic range thereof. Such recording can be a spurious recording made during readout or from spurious sources of light incident on the media. In one embodiment, the reference beam (108) produced in the course of holographic recording is redirected to locations on the media (4) which have already been recorded. The redirected beam post exposes the media to fix these locations against spurious recording. The integrity of the holographic data storage systems and the robustness thereof is improved by fixing methods and apparatus incorporating the invention.

Abstract: Holographic media for storing and reading holographic data is provided having one or more external or internal surfaces having structures for at least one of minimizing reflections from illumination incident the surface, or enhancing adhesion between surfaces within the media. Structures for minimizing reflections represent a grating pattern of subwavelength structures providing low reflectivity at the operating characteristics of holographic optical systems to use the media, such as spectral bandwidth, angular bandwidth, and polarization of illumination incident the media. Adhesion promotion may be provided by structures along an interior surface of the media, such as along an interfacing surface between photosensitive material of the media and a substrate material adjoining the photosensitive material. Such adhesion promotion may be provided by such structured surface with or without providing low reflectivity at the operating characteristics of holographic optical systems to use the media.

Abstract: A method is provided for molding from glass certain complex optical components, such as lenses, microlens, arrays of microlenses, and gratings or surface-relief diffusers having fine or hyperfine microstructures suitable for optical or electro-optical applications. Thereby, mold masters or patterns, which define the profile of the optical components, made on metal alloys, particularly titanium or nickel alloys, or refractory compositions, with or without a non-reactive coating are used. Given that molding optical components from oxide glasses has numerous drawbacks, it has been discovered in accordance with the invention that non-oxide glasses substantially eliminates these drawbacks. The non-oxide glasses, such as chalcogenide, chalcohalide, and halide glasses, may be used in the mold either in bulk, planar, or power forms. In the mold, the glass is heated to about 10–110° C., preferably about 50° C.

Abstract: A method and an apparatus for recording at least two multiplexed holograms. The object beam and the reference beam generated by a coherent light source. Either an object beam or a reference beam is reflected from at least one portion of an aspherical reflecting surface causing the object beam and the reference beam to intersect and form an interference pattern at a plane defined by the intersection of the object and reference beams at a selected storage location in a recording media.

Abstract: The invention is directed to metal-free grating for use in wavelength optical communications, and in particular to metal-free, reflective immersed diffraction gratings. The gratings of the invention area made of at least a first material 1 of refractive index n1 and a second material of refractive index n2. Materials 1 and 2 must obey the Expressions: (I) n1>n2, (II) n1>&lgr;/2L>n2 for single diffracted order at Littrow, and (III) n2/n1<Sin|&thgr;j|<1; wherein &lgr; is the wavelength of the light incident on the grating, &thgr;j represents any and all propagation angles of incident and diffracted light, and L is the grating period. The grating profile is located at the interface of material 1 and to material 2. In one embodiment, the grating profile is made from additional material 3 and 4 of refractive index n3 and n4, respectively, and is placed between materials 1 and 2. In another embodiment the grating is made from silicon.

Abstract: The invention is directed to metal-free grating for use in wavelength optical communications, and in particular to metal-free, reflective immersed diffraction gratings. The gratings of the invention area made of at least a first material 1 of refractive index n1 and a second material of refractive index n2. Materials 1 and 2 must obey the Expressions: (I) n1>n2, (II) n1>&lgr;/2L>n2 for single diffracted order at Littrow, and (III) n2/n1<Sin |&thgr;j|<1; wherein &lgr; is the wavelength of the light incident on the grating, &thgr;j represents any and all propagation angles of incident and diffracted light, and L is the grating period. The grating profile is located at the interface of material 1 and to material 2. In one embodiment, the grating profile is made from additional material 3 and 4 of refractive index n3 and n4, respectively, and is placed between materials 1 and 2. In another embodiment the grating is made from silicon.

Abstract: In one aspect, a method is provided for molding from glass complex optical components such as lenses, microlens, arrays of microlenses, and gratings or surface-relief diffusers having fine or hyperfine microstructures suitable for optical or electro-optical applications. In another aspect, mold masters or patterns, which define the profile of the optical components, made on metal alloys, particularly titanium or nickel alloys, or refractory compositions, with or without a non-reactive coating are provided. Given that molding optical components from oxide glasses has numerous drawbacks, it has been discovered in accordance with the invention that non-oxide glasses substantially eliminates these drawbacks. The non-oxide glasses, such as chalcogenide, chalcohalide, and halide glasses, may be used in the mold either in bulk, planar, or power forms. In the mold, the glass is heated to about 10-110° C., preferably about 50° C.

Abstract: A method for fabricating a structure on a substrate with a low contrast photoresist having a height greater than 15 microns is provided. A uniformly thick film of photoresist is achieved on a substrate by spinning the substrate at two different speeds, then at least partially, but not fully drying the layer of photoresist at ambient temperature. The layer of photoresist is then dried and hardened by applying heat to the bottom surface of the substrate via a hot plate. The substrate is maintained level at all times during the spinning and drying steps in order to prevent wedging of the photoresist which remains in a plastic state until fully hardened by the hot plate. A surface relief pattern is then created in the photoresist via a scanning beam of electromagnetic radiation, which is preferably a laser beam. The resulting exposed surface relief patterns are then developed to produce the desired structure, which has a height of 15 microns or greater.

Abstract: A method for aligning optical fibers to a lens array is provided, including, providing a planar reflective surface facing the front surface of lens array, locating one end of a fiber adjacent the back surface of the substrate upon which the lens array is formed or integrated to face one of the lenses of the array, propagating light through the fiber and the lens facing the fiber to the planar reflective surface, receiving returned reflected light from the reflective surface through the fiber and the lens facing the fiber, and then adjusting the position of the fiber to change the amount of the returned reflected light received by the fiber to determine when the fiber is at a position which provides a maximum amount or power of the returned reflected light, thereby aligning the end of the fiber to the focal point of the lens. The fiber is attached to the substrate at that position, such as by an adhesive material, and the method repeated for each fiber to a different lens of the array.

Abstract: A method for fabricating a structure on a substrate with a low contrast photoresist having a height greater than 15 microns is provided. A uniformly thick film of photoresist is achieved on a substrate by spinning the substrate at two different speeds, then at least partially, but not fully drying the layer of photoresist at ambient temperature. The layer of photoresist is then dried and hardened by applying heat to the bottom surface of the substrate via a hot plate. The substrate is maintained level at all times during the spinning and drying steps in order to prevent wedging of the photoresist which remains in a plastic state until fully hardened by the hot plate. A surface relief pattern is then created in the photoresist via a scanning beam of electromagnetic radiation, which is preferably a laser beam. The resulting exposed surface relief patterns are then developed to produce the desired structure, which has a height of 15 microns or greater.

Abstract: A method for aligning optical fibers to a lens array is provided, including, providing a planar reflective surface facing the front surface of lens array, locating one end of a fiber adjacent the back surface of the substrate upon which the lens array is formed or integrated to face one of the lenses of the array, propagating light through the fiber and the lens facing the fiber to the planar reflective surface, receiving returned reflected light from the reflective surface through the fiber and the lens facing the fiber, and then adjusting the position of the fiber to change the amount of the returned reflected light received by the fiber to determine when the fiber is at a position which provides a maximum amount or power of the returned reflected light, thereby aligning the end of the fiber to the focal point of the lens. The fiber is attached to the substrate at that position, such as by an adhesive material, and the method repeated for each fiber to a different lens of the array.

Abstract: Fabrication of arbitrary profile micro-optical structures (lenses, gratings, etc.) and, if desired, with optomechanical alignment marks simultaneously during fabrication is based upon the use of low-contrast photosensitive material that, when exposed to a spatially variable energy dosage of electromagnetic radiation, can be processed to achieve multi-level or continuous surface-relief microstructures. By varying the exposure dose spatially based upon predetermined contrast curves of the photosensitive material, arbitrary one-dimensional (1-D) or two-dimensional (2-D) surface contours, including spherical, aspherical, toroidal, hyperbolic, parabolic, and ellipsoidal, can be achieved with surface sags greater than 15 &mgr;m. Surface profiles with advanced phase correction terms (e.g., Zernike polynomials) can be added to increase the alignment tolerance and overall system performance of the fabricated structure can also be fabricated.