Abstract: An authentication system using a correlator that correlates an input with a reference wherein at least one of the input and reference comprises a phase volume mask having structures, preferably points, that are each less than about six microns in size and can have an aspect ratio (AR) greater than 1:1 so as to produce a phase encoded random pattern having millions of combinations in a mask that is as small as one square millimeter. The random pattern can be convolved with a second pattern, such as a biometric pattern, to produce a phase convolved mask. The correlator preferably is a nonlinear joint transform correlator that can use “chirp” encoding to permit the input to be located in a different plane than the reference. The correlator optically Fourier transforms images of the reference and input that are thereafter nonlinearly transformed and inverse Fourier transformed by a processor to determine the presence or absence of a correlation spike indicative of authenticity.

Abstract: An authentication system using a correlator that correlates an input with a reference wherein at least one of the input and reference comprises a phase volume mask having structures, preferably points, that are each less than about six microns in size and can have an aspect ratio (AR) greater than 1:1 so as to produce a phase encoded random pattern having millions of combinations in a mask that is as small as one square millimeter. The random pattern can be convolved with a second pattern, such as a biometric pattern, to produce a phase convolved mask. The correlator preferably is a nonlinear joint transform correlator that can use “chirp” encoding to permit the input to be located in a different plane than the reference. The correlator optically Fourier transforms images of the reference and input that are thereafter nonlinearly transformed and inverse Fourier transformed by a processor to determine the presence or absence of a correlation spike indicative of authenticity.

Abstract: An authentication system using a correlator that correlates an input with a reference wherein at least one of the input and reference comprises a phase volume mask having structures, preferably points, that are each less than about six microns in size and can have an aspect ratio (AR) greater than 1:1 so as to produce a phase encoded random pattern having millions of combinations in a mask that is as small as one square millimeter. The random pattern can be convolved with a second pattern, such as a biometric pattern, to produce a phase convolved mask. The correlator preferably is a nonlinear joint transform correlator that can use “chirp” encoding to permit the input to be located in a different plane than the reference. The correlator optically Fourier transforms images of the reference and input that are thereafter nonlinearly transformed and inverse Fourier transformed by a processor to determine the presence or absence of a correlation spike indicative of authenticity.

Abstract: An improved method for generating masters having a plurality of randomly distributed speckle suitable for making seamless light shaping diffusers of virtually any size and at low cost is disclosed herein. The method utilizes incoherent light to record a desired speckle pattern in a photosensitive medium which is then exposed in an imagesetter.

Abstract: Systems and methods for providing an LGD with a collimated backlight and a non-Lambertian diffuser are described.

Abstract: Systems and methods for providing an LCD backlight are described. An LCD backlight system includes: a beam bending and viewing film including a first side including a surface diffuser and a second side including a plurality of substantially parallel optical elements, each of the plurality of substantially parallel optical elements including a first facet that includes a refractive surface and a second facet that includes a total internal reflection surface. The systems and methods provide advantages in that light from the LCD backlight is bright and homogenous.

Abstract: Systems and methods for providing an LCD with a collimated backlight and a non-Lambertian diffuser are described.

Abstract: A holographic filter comprises a volume hologram recorded with Bragg surfaces for use in spectroscopic and spectral splitting applications. The Bragg planes in the holographic filter can be recorded to satisfy virtually any design constraint imposed upon the filter such as Raman, Lippmann, non-Snellian (slanted), curved, and multiplexed spectral filters. The holographic filter achieves maximal reduction of secondary maxima and sidelobes and obtains large wavelength selectivities, and varied grating constants.

Abstract: A holographic filter comprises a volume hologram recorded with Bragg surfaces for use in spectroscopic and spectral splitting applications. The Bragg planes in the holographic filter can be recorded to satisfy virtually any design constraint imposed upon the filter such as Raman, Lippmann, non-Snellian (slanted), curved, and multiplexed spectral filters. The holographic filter achieves maximal reduction of secondary maxima and sidelobes and obtains large wavelength selectivities, and varied grating constants.

Abstract: An apparatus for recording Lippman holographic mirrors comprises an exposing volume optically coupled on one side with an index-matching fluid to the holographic material to be recorded. The volume is exposed on an adjacent side to a light beam expanded in one direction into a plane of light whose projection on the volume is a line. The line of light and the holographic material are moved relative to each other on an interrupted or a continuous basis to expose the holographic material.

Abstract: A high-speed light modulator employing surface plasmon wave coupling comprises a metal-dielectric interface positioned adjacent to and externally of a waveguide carrying totally internally reflected light waves. A high frequency voltage applied to the interface causes the dielectric, in the preferred case an ultra-fast electro-optic polymer, to resonate, generating a surface plasmon wave at the interface. The plasmon wave couples with the evanescent wave portion of the light waves in the waveguide. The output intensity of the light waves varies inversely with the strength of coupling between the light wave and surface plasmon wave modes. The modulator eliminates bulk and alignment problems associated with state of the art modulators and can be employed in integrated optic circuits.

Abstract: A wavelength division multiplexer/demultiplexer having optical path lengths between a fiber array and a Fourier transform lens, and between a dispersion grating and the lens equal to the focal length of the lens. The equal optical path lengths reduce losses due to angular acceptance mismatch in the multiplexer. Close orientation of the fiber array about the optical axis and the use of a holographic dispersion grating reduces other losses in the system. Multi-exposure holographic dispersion gratings enable the multiplexer/demultiplexer for extremely broad-band simultaneous transmission and reflection operation. Individual Bragg plane sets recorded in the grating are dedicated to and operate efficiently on discrete wavelength ranges. A volume Bragg vertically non-uniform holographic grating enables operation of the multiplexer or other devices that act on light waves according to wavelength over nearly the full usable 0.8-1.3 .mu.m wavelength range.

Abstract: An apparatus for coupling light waves into a single-mode planar waveguide comprises a curved multi-mode waveguide. The multi-mode waveguide is thick so that its mode structure is practically continuous and its coupling wavelength selectivity is low. The curved multi-mode waveguide presents a variable single-mode coupling gap to the adjacent single-mode planar waveguide which achieves optimum balance between phase and amplitude conditions for coupling a broad range of wavelengths and tolerates varying wavelength light sources.

Abstract: A diffraction coherence filter based on Bragg interference principles comprises a plurality of spaced-apart lower-hierarchy optical elements, containing a series of interference structures, which form a higher-hierarchy compound optical structure. The spatial distribution of the lower-hierarchy optical element and the interference structures is governed by mathematical relationships dependent upon the coherence radius and temporal coherence length of incoming radiation. All of the lower-hierarchy elements can be coherently coupled for coherent light and randomly coupled for incoherent light, whereby the filter may differentiate between coherent and incoherent radiation.

Abstract: A wavelength division multiplexer/demultiplexer having optical path lengths between a fiber array and a Fourier transform lens, and between a dispersion grating and the lens equal to the focal length of the lens. The optical path lengths reduce losses due to angular acceptance mismatch in the multiplexer. Close orientation of the fiber array about the optical axis and the use of a holographic dispersion grating reduces other losses in the system. Multi-exposure holographic dispersion gratings enable the multiplexer/demultiplexer for extremely broad-band simultaneous transmission and reflection operation. Individual Bragg plane sets recorded in the grating are dedicated to and operate efficiently on discrete wavelength ranges.

Abstract: An optical interconnect employing planar volume Bragg hologram technology in two dimensions comprises a dichromated gelatin planar volume Bragg hologram disposed in a glass planar optical path. Multiplexed Bragg plane sets selectively diffract information-bearing light signals such as voice, image, or computer data signals in a VLSI system from a laser diode or LED source coupled to the planar optical path toward high-speed photodiodes. The holographic planar optical interconnect can interconnect up to 1000 different signals between VLSI microelectronic components and systems.