Abstract: A system of beam steering using electrical operation. A first system provides a grating and a liquid crystal material. When the liquid crystal is unenergized, there is a mismatch between the liquid crystal and the grating, causing the grating to diffract the light in a specified direction. The liquid crystal is energized to match its index of refraction to the grating. Then, the light is not diffracted by the grating, and hence travels in a different direction then it would when the liquid crystal was not energized. Another, finer system, forms electrically generated gratings using a liquid crystal material.

Abstract: A system of reproducing multiplexed holographic information from one master medium (100, 300, 400, 500, 600, 720) to another replicate medium (200, 310, 410, 510, 610, 730) simultaneously reads out the information from all multiplexed master holograms within the master medium. The replica has different phase and amplitude distributions from the master medium containing a plurality of multiplexed holograms (420, 520) though both the replica and the master contain the identical holographic information of the original objects.

Abstract: An optical memory for storing and/or reading data on an optical disk. The optical disk incorporates a material in which holographic gratings can be created at plural locations within the disk. An electro-optical head which is capable of creating these holographic gratings at any one of the plural locations is employed. The head is additionally capable of detecting the presence or absence of a holographic grating at any one of these plural locations. The presence of the holographic grating could indicate a first binary state and the absence of the holographic grating indicate a second state. Alternately, the electro-optical head could be used to vary the diffraction efficiency of the holographic gratings during their creation. In that case, the head would also be capable of detecting this variation in efficiency and produce a proportional detection signal. This signal would be used as an indicator of the value of the stored data element.

Abstract: An identification system using biometric information of human body parts and a secret sequence code. In particular, biometric information of human body parts is used to form the secret sequence code. Specifically, a combination entry device recognizes user's fingerprints which are entered as a sequence. The fingerprints must be entered in the proper sequence in order to be recognized by the system. The fingerprints are preferably recognized using a fast technique with a low-probability level of rejection. While the sensor can be fooled for any one fingerprint. The use of a plurality of different fingerprints improves the identification capability. In particular, the combination of fingerprints in the proper order is necessary to undo the lock.

Abstract: An identification system using biometric information of human body parts and a secret sequence code. In particular, biometric information of human body parts is used to form the secret sequence code. Specifically, a combination entry device recognizes user's fingerprints which are entered as a sequence. The fingerprints must be entered in the proper sequence in order to be recognized by the system. The fingerprints are preferably recognized using a fast technique with a low-probability level of rejection. While the sensor can be fooled for any one fingerprint. The use of a plurality of different fingerprints improves the identification capability. In particular, the combination of fingerprints in the proper order is necessary to undo the lock.

Abstract: A method and a compact apparatus to read shift-multiplexed holograms on a storage medium without the need for any lenses, and without the need for moving the storage medium. The shift-multiplexed holograms have centers at different locations. The apparatus can generate an array of diverging spherical waves of reference beams, each for illuminating one of the holograms. Each hologram is read as an image on a detector array by illuminating that hologram with a corresponding diverging spherical wave of reference beam. Different holograms can be read by illuminating the medium with a different diverging spherical reference beam. The diverging beams can be from an array of sources, or can be from switching one source.

Abstract: The present invention discloses nanomechanical fabrication methods of hybrid aligned nematic (HAN) cells of liquid crystals for creating analog spatial light modulators and smart pixel arrays on conventionally fabricated VLSI integrated circuits. The liquid crystal material is encapsulated between a top substrate and a bottom substrate. The locally averaged direction of the long axis of the molecules of liquid crystals of the HAN cells varies smoothly from homogeneous alignment on a top substrate to homeotropic alignment on a bottom substrate. The bottom substrate causes a homeotropic alignment of the liquid crystal because of its porous microstructure.

Abstract: A non-volatile holographic recording method and system based on a doubly-doped photorefractive material. One embodiment of the holographic material is doped to have first and second types of dopants that are operable to produce charge carriers to a common band in response to radiation of a specified wavelengths. Charge carriers in the common band can migrate to a different spatial location. The dopants are also capable of recombining with charge carriers in the common band. The first type of dopants have a first dopant energy level below the band by a first energy gap greater than a second energy gap of a second dopant energy level of the second type of dopants below the common band. The first and second dopant energy levels are separated from each other so that their absorption bands to the common band are substantially separated. In addition, the first and second energy gaps should be much greater than the thermal energy k.sub.

Abstract: An architecture for holographic data storage and processing integrates multifunctional silicon-based optoelectronic devices, rewritable holographic material, optical devices and other electro-optical elements in compact and high-performance systems. A dynamic hologram refresher based on optoelectronic integrated circuits has a smart pixel structure including an electrically addressed SLM to write a new data page, a thresholding detector array for readout, and a memory to latch the data from the detector to the modulator in each pixel. In particular, conjugate reconstruction is used in combination with the dynamic hologram refresher to retrieve data from volume multiplexed holograms in the rewritable holographic material.

Abstract: Methods and apparatus to reconfigure a programmable logic device on a chip. The device includes a number of configurable elements. The methods include the steps of retrieving reconfiguration data pre-stored in a memory device located apart from the chip, and transferring the retrieved reconfiguration data in parallel to each of the configurable elements. One approach pre-stores the data in holograms.

Abstract: A method and a compact apparatus to read shift-multiplexed holograms on a storage medium without the need for any lenses, and without the need for moving the storage medium. The shift-multiplexed holograms have centers at different locations. The apparatus can generate an array of diverging spherical waves of reference beams, each for illuminating one of the holograms. Each hologram is read as an image on a detector array by illuminating that hologram with a corresponding diverging spherical wave of reference beam. Different holograms can be read by illuminating the medium with a different diverging spherical reference beam. The diverging beams can be from an array of sources, or can be from switching one source.

Abstract: A method and a system to re-align onto a detector array a holographic image of a Fourier region hologram stored in a medium, with the medium spinning around a first axis, and the hologram being generated by a reference beam and a signal beam. In generating the hologram, the reference beam is incident on the medium with respect to a second axis at a second-axis-incident angle, and a third axis at a third-axis-incident angle, such that the holographic image of the hologram when reproduced by the reference beam is aligned onto the detector array. Also, the three axes are substantially orthogonal to each other. As the medium spins, the medium's orientation can change through tilting with respect to the second and the third axes so that the holographic image when reproduced by the reference beam is not aligned onto the detector array.

Abstract: The present invention is a holographic reconstruction device for reconstructing successive holograms previously recorded by a recording reference beam in a recording medium, each previously recorded successive hologram being spaced apart a recording displacement. The recording reference beam has a recording wavelength in the range where the recording medium is photosensitive and a recording propagation angle. The device comprises a reconstruction mechanism having a reconstruction reference beam with a reconstruction wavelength in the range where the recording medium is relatively photo-insensitive and a reconstruction propagation angle. The reconstruction reference beam is provided onto the recording medium. Also, a succession of relative displacements in the recording medium is produced and each of the displacements are equal to the distance of the recording displacements with which the holograms were previously recorded.

Abstract: An architecture for holographic data storage and processing integrates multifunctional silicon-based optoelectronic devices, rewritable holographic material, optical devices and other electro-optical elements in compact and high-performance systems. A dynamic hologram refresher based on optoelectronic integrated circuits has a smart pixel structure including an electrically addressed SLM to write a new data page, a thresholding detector array for readout, and a memory to latch the data from the detector to the modulator in each pixel. In particular, conjugate reconstruction is used in combination with the dynamic hologram refresher to retrieve data from volume multiplexed holograms in the rewritable holographic material.

Abstract: The invention is embodied in a method of recording successive holograms in a recording medium, using at least a fan of M waves along at least a first axis with a separation angle between adjacent waves and directing the fan of M waves as a reference beam along a reference beam path onto the recording medium, successively modulating a wave with a succession of images to produce a succession of signal beams along a signal beam path lying at a propagation angle relative to the reference beam path so that the signal and reference beams intersect at abeam intersection lying within the medium, the beam intersection having a size corresponding to beam areas of the reference and signal beams, producing a succession of relative displacements in a direction parallel to the first axis between the recording medium and the beam intersection of the signal and reference beam paths in synchronism with the succession of signal beams, each of the displacements being less than the size of the intersection whereby to record succ

Abstract: An identification system using biometric information of human body parts and a secret sequence code. In particular, biometric information of human body parts is used to form the secret sequence code. Specifically, a combination entry device recognizes user's fingerprints which are entered as a sequence. The fingerprints must be entered in the proper sequence in order to be recognized by the system. The fingerprints are preferably recognized using a fast technique with a low-probability level of rejection. While the sensor can be fooled for any one fingerprint. The use of a plurality of different fingerprints improves the identification capability. In particular, the combination of fingerprints in the proper order is necessary to undo the lock.

Abstract: A corneal topographer based on conoscopic holography with partially coherent illumination. Corneal topographic measurements can be accomplished at a processing rate higher than the standard video rate of 30 Hz. The conoscopic measurements can be used in an opto-electronic servo to control a photorefractive keratectomy system in real time for an improved accuracy in laser ablation of a corneal surface.

Abstract: A system and method for measuring the dimensions of a small (e.g., microelectronic) structure. The present invention is an optical system and method that uses a polarized light beam, reflected off or transmitted through, a structure, to measure the structural parameters, such as the lateral dimensions, vertical dimensions, height, or the type of structural material. The system employs a light source to generate a light beam that is polarized and focused onto the structure to be measured. The structure is illuminated with TE and TM polarized light. The structure is dimensioned such that the TM and TE fields are affected differently by the diffraction off the structure. As a result, either the TE or TM field can be used as a reference to analyze the phase and amplitude changes in the other field. Differences between the diffracted TE and TM far fields allow a comparison of the relationship between the amplitude and phase of those fields to determine the structural parameters of a structure.

Abstract: The present invention discloses nanomechanical fabrication methods of hybrid aligned nematic (HAN) cells of liquid crystals for creating analog spatial light modulators and smart pixel arrays on conventionally fabricated VLSI integrated circuits. The liquid crystal material is encapsulated between a top substrate and a bottom substrate. The locally averaged direction of the long axis of the molecules of liquid crystals of the HAN cells varies smoothly from homogeneous alignment on a top substrate to homeotropic alignment on a bottom substrate. The bottom substrate causes a homeotropic alignment of the liquid crystal because of its porous microstructure.

Abstract: A method of verifying the authenticity of an object is disclosed employing a spatial integrating optical correlator. An unreadable and hence non-counterfeitable mask (e.g., a. complex mask or a phase mask) is coupled to the object and the optical correlator compares the mask with a reference mask on which it is scanned over. The correlator produces a correlation spot or image having an intensity which exceeds a given level if the mask is genuine. An alternate embodiment includes a fingerprint or other personalized pattern bonded to the mask, and the fingerprint or other personalized pattern on the card is compared to a reference fingerprint or other personalized pattern of the card holder for added security.