Abstract: A collimator array is disclosed that carries forward its alignment characteristics to optical devices that incorporate it. Little, if any active alignment need be performed in the manufacturing of such optical devices, such as switching arrays and optical add/drop arrays that employ a plurality of such collimator arrays in each device. The collimator array includes a fiber array having a plurality of regularly spaced optical fibers such that an output axis of each optical fiber has a predetermined spatial position and orientation with respect to a reference edge of the fiber array. The collimator array also includes an array of lenses separated from the fiber array by an air gap and aligned with the fiber array at an alignment position. The aligned position is such that collimated light exiting each lens has a predetermined position and direction with respect to the reference edge of the fiber array.

Abstract: An assembly that could be used either as a switch or an attenuator includes two or more optical channels defined by lithography within a substrate. The two or more optical channels are positioned so that the ends of the optical channels are at or near an edge of the substrate. A moveable MEMS mirror is positioned near the edge of the substrate and the openings, with the face of the mirror positioned to receive an optical signal from one of the optical channels. The mirror can direct an optical signal from one of the optical channels into another of the optical channels. Mirror position can be changed to alter the path of the optical signal and to change the coupling between the optical channels. In this way, the assembly of optical channels within the substrate and the MEMS mirror can act as a switch or as an attenuator.

Abstract: A tap coupler device for an optical array is formed either in a waveguide structure or in a V block in which a fiber array may be mounted. The tap coupler device may include a substrate with main and tap waveguides formed therein, and waveguide tap couplers formed in the substrate for diverting a portion of the optical signal from the main waveguides to corresponding tap waveguides. Another variation includes a substrate including waveguides, with the surface of the substrate where the waveguides end inclined to reflect a portion of the signals in the waveguides toward the top surface of the substrate. Yet another variation includes an input V block having input fibers. The surface of the V block where the input fibers terminate is inclined to reflect a portion of light signals from the input fibers toward the top surface of the V block.

Abstract: An assembly that could be used either as a switch or an attenuator includes two or more optical channels defined by lithography within a substrate. The two or more optical channels are positioned so that the ends of the optical channels are at or near an edge of the substrate. A moveable MEMS mirror is positioned near the edge of the substrate and the openings, with the face of the mirror positioned to receive an optical signal from one of the optical channels. The mirror can direct an optical signal from one of the optical channels into another of the optical channels. Mirror position can be changed to alter the path of the optical signal and to change the coupling between the optical channels. In this way, the assembly of optical channels within the substrate and the MEMS mirror can act as a switch or as an attenuator.

Abstract: An optical add/drop module includes an add channel, an input channel, a drop channel and an output channel, with each channel aligned to transmit or receive light reflected from a common mirror in at least one state of the add/drop module. Rotating the mirror changes the state of the module. In the module's add/drop state, light from the input channel reflects from the mirror into the drop channel and light from the add channel reflects off the mirror to the output channel. In the module's pass through state, light from the input channel reflects off the mirror into the output channel and light from the add channel reflects off the mirror to a position other than the drop channel. Arrays of add, input, drop and output channels can be coupled to a linear array of independent micro-electromechanical mirrors to provide an integrated set of optical add/drop modules.

Abstract: An optical add/drop module includes an add channel, an input channel, a drop channel and an output channel, with each channel aligned to transmit or receive light reflected from a common mirror in at least one state of the add/drop module. Rotating the mirror changes the state of the module. In the module's add/drop state, light from the input channel reflects from the mirror into the drop channel and light from the add channel reflects off the mirror to the output channel. In the module's pass through state, light from the input channel reflects off the mirror into the output channel and light from the add channel reflects off the mirror to a position other than the drop channel. Arrays of add, input, drop and output channels can be coupled to a linear array of independent micro-electromechanical mirrors to provide an integrated set of optical add/drop modules.

Abstract: A method is provided for reconstructing an image transmitted through a thick distorting medium. A remote source provides coherent light at the object plane, and a local source, typically derived from the remote source, provides corresponding light that is coherent with respect to the remote source. Light from the remote source is directed through the thick aberrator and into a holographic medium, such as a photorefractive crystal, to interact with corresponding light from the local source and produce a volume hologram. An angularly multiplexed volume hologram, which covers the entire object field, is written into the holographic medium by successive exposures of light from the remote and local sources for successive pixels of the object plane. Light from an object, which comprises two-dimensional information from the object plane, can be reconstructed by the volume hologram after being distorted by the thick aberrator.

Abstract: An optical image enhancer includes a beam of coherent light for carrying an input image and a first lens for receiving the beam and performing a spatial Fourier transform of the input image. A photorefractive crystal at the Fourier plane receives the transformed image, while a coherent pump beam illuminates selected spatial frequency components of the transformed image at the Fourier plane, thereby transferring energy to the selected frequencies by two-beam coupling. A second lens receives the transformed image from the Fourier plane and performs a spatial Fourier transform of the transformed image, thereby reproducing the input image in an output image which contains intensified features corresponding to the selected spatial frequency components. A spatial light modulator may be used to cause the pump beam to illuminate the selected spatial frequency components of the transformed image at the Fourier plane.

Abstract: A mutually pumped phase conjugator (MPPC) is used to remove spatial distortions from a high power laser beam. The high power beam with its "dirty" spatial profile is directed into one side of the MPPC. A spatially clean beam at the same nominal frequency as the high power beam is output from a continuous wave (CW) laser and directed into the opposite side of the MPPC. As a result of mutually pumped phase conjugation, the MPPC returns a phase conjugate beam that retains the clean spatial profile of the CW beam but acquires the temporal characteristics of the high power beam. A Faraday isolation system may be used to separate the phase conjugate beam from the incident CW beam to provide an output beam having a clean spatial profile. If desired, the high power beam can be transformed into an image bearing output beam simply by modifying the incident CW beam with a transparency or spatial light modulator.

Abstract: A phase-conjugate optical communication system includes a first source of coherent radiation for producing a first beam having a nominal wavelength .lambda. and a first modulator for temporally modulating the first beam. A second source of coherent radiation, mutually incoherent with the first source, produces a second beam having the nominal wavelength .lambda., while a second modulator temporally modulates the second beam. A mutually pumped phase conjugator is positioned such that the first and second beams fan in the conjugator and produce a set of shared fanning holograms, the holograms causing a third beam, which is the phase conjugate of the first beam and on which is imposed the temporal modulation of the second beam, to be diffracted in a direction opposite to the first beam and causing a fourth beam, which is the phase conjugate of the second beam and on which is imposed the temporal modulation of the first beam, to be diffracted in a direction opposite to the second beam.

Abstract: A phase conjugate interferometer for combining first and second two dimensional images includes a source of coherent light and a first beam splitter for dividing the coherent light into a transmitted beam and a reflected pump beam. A second beam splitter divides the transmitted beam into a reflected first probe beam which traverses a first image transparency and a transmitted second probe beam which traverses a second image transparency.