Abstract: An optical switch is disclosed having what may be characterized as an optically-induced grating. One embodiment of such an optical switch includes first and second waveguides. An optical mask is formed on a side of the first waveguide opposite that which faces the second waveguide. Multiple slits exist in this optical mask in alignment with an output from a light source. Changing the mode of this light force changes the output of the light source directed onto the slits, and changes the state of the first and second waveguides from being optically decoupled to optically coupled.

Abstract: A demultiplexer is disclosed. The demultiplexer incorporates a reflective grating that is associated with a first waveguide through which a multiplexed optical signal may be transmitted. Individual wavelengths of light that have been reflected by the reflective grating are able to pass through a barrier layer which separates the first waveguide from a second waveguide. A plurality of photodetectors are associated with the second waveguide to read out the individual, wavelength-specific optical signals. The reflective grating is preferably formed on a surface of the first waveguide which projects away from the second waveguide, while the photodetectors are preferably formed at least in part by processing a surface of the second waveguide that projects away from the first waveguide. Both polarities of light are preferably accounted for/collected by the grating as well.

Abstract: A demultiplexer is disclosed. The demultiplexer incorporates a reflective grating that is associated with a first waveguide through which a multiplexed optical signal may be transmitted. Individual wavelengths of light that have been reflected by the reflective grating are able to pass through a barrier layer which separates the first waveguide from a second waveguide. A plurality of photodetectors are associated with the second waveguide to read out the individual, wavelength-specific optical signals. The reflective grating is preferably formed on a surface of the first waveguide which projects away from the second waveguide, while the photodetectors are preferably formed at least in part by processing a surface of the second waveguide that projects away from the first waveguide. Both polarities of light are preferably accounted for/collected by the grating as well.

Abstract: An optical switch is disclosed having what may be characterized as an optically-induced grating. One embodiment of such an optical switch includes first and second waveguides. An optical mask is formed on a side of the first waveguide opposite that which faces the second waveguide. Multiple slits exist in this optical mask in alignment with an output from a light source. Changing the mode of this light force changes the output of the light source directed onto the slits, and changes the state of the first and second waveguides from being optically decoupled to optically coupled.

Abstract: A demultiplexer is disclosed. The demultiplexer incorporates a reflective grating that is associated with a first waveguide through which a multiplexed optical signal may be transmitted. Individual wavelengths of light that have been reflected by the reflective grating are able to pass through a barrier layer which separates the first waveguide from a second waveguide. A plurality of photodetectors are associated with the second waveguide to read out the individual, wavelength-specific optical signals. The reflective grating is preferably formed on a surface of the first waveguide which projects away from the second waveguide, while the photodetectors are preferably formed at least in part by processing a surface of the second waveguide that projects away from the first waveguide. Both polarities of light are preferably accounted for/collected by the grating as well.

Abstract: A demultiplexer is disclosed. The demultiplexer incorporates a reflective grating that is associated with a first waveguide through which a multiplexed optical signal may be transmitted. Individual wavelengths of light that have been reflected by the reflective grating are able to pass through a barrier layer which separates the first waveguide from a second waveguide. A plurality of photodetectors are associated with the second waveguide to read out the individual, wavelength-specific optical signals. The reflective grating is preferably formed on a surface of the first waveguide which projects away from the second waveguide, while the photodetectors are preferably formed at least in part by processing a surface of the second waveguide that projects away from the first waveguide. Both polarities of light are preferably accounted for/collected by the grating as well.

Abstract: An optical memory material includes a two-photon storage component which can be written from a first to a second state in response to WRITE light, mixed with a signal component which fluoresces by one-photon absorption only at the written locations in response to READ light. The storage material may be a fulgide. The memory material may also include a frequency upconversion material to aid writing. Writing is performed by a spatial light modulator (SLM) with a dynamic focussing system, for concentrating sufficient power at WRITE locations for nonlinear two-photon absorption. Crosstalk is avoided during simultaneous writing in some embodiments, by spacing the individual WRITE beams apart by an integer number of inter-beam spacings, so that non-adjacent datels are written simultaneously in a "paragraph," and the non-written areas are written at a different time with different paragraphs.

Abstract: A built-in-test capability is provided for determining the integrity of an optical fiber connecting: (a) an optical firing unit having a primary light source emitting a first wavelength, a test light source emitting a second wavelength different from the first wavelength, a mechanism both for coupling light from the light sources to the optical fiber and also for coupling the return light to a detector; and (b) an optically-initiated device which is coupled to a second end of the optical fiber. The apparatus includes a photoluminescent material disposed at a junction of the optically-initiated device and the second end of the optical fiber. In test mode, this photoluminescent material is exposed to the test light source, which results in photoluminescence at a third wavelength. The photoluminescent light travels through the optical fiber to the detector, and when detected indicates optical fiber continuity.

Abstract: A built-in-test capability is provided for determining the integrity of an optical fiber connecting: (a) an optical firing unit having a primary light source emitting a first wavelength, a test light source emitting a second wavelength different from the first wavelength, a mechanism both for coupling light from the light sources to the optical fiber and also for coupling the return light to a detector; and (b) an optically-initiated device which is coupled to a second end of the optical fiber. The apparatus includes a photoluminescent material disposed at a junction of the optically-initiated device and the second end of the optical fiber. In test mode, this photoluminescent material is exposed to the test light source, which results in photoluminescence at a third wavelength. The photoluminescent light travels through the optical fiber to the detector, and when detected indicates optical fiber continuity.

Abstract: A built-in-test capability is provided for determining the integrity of an optical fiber connecting: (a) an optical firing unit having a primary light source emitting a first wavelength, a test light source emitting a second wavelength different from the first wavelength, a mechanism both for coupling light from the light sources to the optical fiber and also for coupling the return light to a filter/detector; and (b) an optically initiated device which is coupled to a second end of the optical fiber. The apparatus includes a photoluminescent material disposed at a junction of the optically initiated device and the optical-fiber-second-end. This photoluminescence material photoluminesces at a third wavelength (when exposed to the test light source), and the light travels through the optical fiber and, when detected indicates optical fiber continuity.

Abstract: A SAR radar has an optical processor which uses an electrical-signal-to-light modulator. The modulator includes a tapped delay line which may be either analog or digital, and the signals tapped from the delay line are applied to an array of temporary storage elements, which in the case of analog signals may be a capacitive sample-and-hold, or for digital signals may include storage registers. In order to improve the signal-to-noise ratio (SNR) by comparison with a processor using an acoustic modulator, the signals tapped from the delay line are sampled at a display sampling rate, which is very low by comparison with the signal sampling rate or the highest frequency of interest, and the sampled signals are held until the next following display rate pulse. The signals held in the temporary storage elements are applied to the modulator elements, so that the optical pattern remains fixed for relatively long periods of time during which the optical processing can integrate photons for improved SNR.

Abstract: A device for converting a set of electronic signals that represent an image into a coherent image includes a two-dimensional array of asymmetric Fabry-Perot (ASFP), quantum-well-based optical modulators connected on a pixel-by-pixel basis to a two-dimensional array of drive circuits located on an integrated circuit. Electronic signals received by the integrated circuit cause the pixel drive circuits to change a bias voltage applied across the optical modulator section and, thereby, change the optical properties of the optical modulator section of the device. The two-dimensional array can be used to impart intensity-only, phase-only, or phase-and-intensity variations onto a beam of coherent laser light incident on the array. This coherent image can be used with other optical elements to form optical processing machines and optical storage devices.

Abstract: An optical memory material includes a two-photon storage component which can be written from a first to a second state in response to WRITE light, mixed with a signal component which fluoresces by one-photon absorption only at the written locations in response to READ light. The storage material may be a fulgide. The memory material may also include a frequency upconversion material to aid writing. Writing is performed by a spatial light modulator (SLM) with a dynamic focussing system, for concentrating sufficient power at WRITE locations for nonlinear two-photon absorption. Crosstalk is avoided during simultaneous writing in some embodiments, by spacing the individual WRITE beams apart by an integer number of inter-beam spacings, so that non-adjacent datels are written simultaneously in a "paragraph," and the non-written areas are written at a different time with different paragraphs.

Abstract: A method and apparatus for simply and accurately determining the index of refraction of semiconductor materials, etalon bars and materials transparent to infrared radiation. The channel spectra of the material is obtained by passing through it a portion of radiation from a continuously tuned diode laser. Another portion of the diode laser radiation is heterodyned with radiation from a CO.sub.2 laser to obtain heterodyne marker beats. The channel spectra and marker beats are displayed in conjunction whereby the frequency difference between the marker beats can be related to the number of fringes in the channel spectra between the marker beats.