Abstract: A network for multi-bit word parallel communication between optoelectronic chips on a two dimensional array of optical input and output channels carried on a single dimension of optical fibers. Each bit of a word is carried on a different wavelength and the multiple wavelengths carrying a word are wavelength multiplexed onto a single optical fiber. Multiple fibers can be joined into a one dimensional array of fibers. A transceiver for transmitting and receiving along the optical data channels comprises an array of modulators powered by individual wavelength light beams, either from individual monochromatic light sources and a light beam from a single broadband light source made to pass through a diffraction grating. The modulators are positioned so that each modulator reflects a different wavelength light beam, thereby providing multiple optical channels. Alternatively, multiple wavelengths are generated from CMOS integrated light sources.

Abstract: A network for multi-bit word parallel communication between optoelectronic chips on a two dimensional array of optical input and output channels carried on a single dimension of optical fibers. Each bit of a word is carried on a different wavelength and the multiple wavelengths carrying a word are wavelength multiplexed onto a single optical fiber. Multiple fibers can be joined into a one dimensional array of fibers. A transceiver for transmitting and receiving along the optical data channels comprises an array of modulators powered by individual wavelength light beams, either from individual monochromatic light sources and a light beam from a single broadband light source made to pass through a diffraction grating. The modulators are positioned so that each modulator reflects a different wavelength light beam, thereby providing multiple optical channels. Alternatively, multiple wavelengths are generated from CMOS integrated light sources.

Abstract: A network for multi-bit word parallel communication between optoelectronic chips on a two dimensional array of optical input and output channels carried on a single dimension of optical fibers. Each bit of a word is carried on a different wavelength and the multiple wavelengths carrying a word are wavelength multiplexed onto a single optical fiber. Multiple fibers can be joined into a one dimensional array of fibers. A transceiver for transmitting and receiving along the optical data channels comprises an array of modulators powered by individual wavelength light beams, either from individual monochromatic light sources and a light beam from a single broadband light source made to pass through a diffraction grating. The modulators are positioned so that each modulator reflects a different wavelength light beam, thereby providing multiple optical channels. Alternatively, multiple wavelengths are generated from CMOS integrated light sources.

Abstract: The present invention provides synchronization of logic signals in a digital system using optical pulses generated from optical modulators. In one embodiment of the present invention, electrically driven optical modulators are positioned at electrical outputs of interest, and the modulators are read out in accordance with synchronized optical pulses produced from a timing source, where the optical pulse lengths are relatively short compared to the electrical output pulse length. The resulting modulated optical pulses output from the optical modulators are then all once more synchronous, with the skew in the original electrical signals having been removed. These optical pulses can then be communicated over optical channels, such as fiber or free space, with well controlled delay, thereby also reducing problems of variable delay in electrical connections.

Abstract: For use in a soliton optical pulse transmission system, an apparatus for, and method of, increasing a signal-to-noise ratio of the system. The apparatus includes: (1) a component for receiving a soliton and an accompanying background noise from the system and increasing a power density of the soliton and the accompanying background noise and (2) a saturable absorber, having a predetermined recombination rate, for receiving and absorbing a portion of the soliton and the accompanying background noise, the predetermined recombination rate causing the saturable absorber to absorb a lesser portion of the soliton than of the accompanying background noise, the component having increased the power density of the soliton and the accompanying background noise to increase a sensitivity of the saturable absorber, the apparatus thereby increasing the signal-to-noise ratio of the system.

Abstract: An apparatus and method provides optical multiple wavelength signals using a single optical broadband source to generate many independent optical wavelength channels. An optical transmitter includes a pulse chirping device which separates the frequency components of periodic optical pulses in the time domain forming separate wavelength channels which are separately modulated by a high-speed broadband optical modulator. A receiver includes a passive splitter to separate the individual wavelength channels. The chirped-pulse transmitter can then be conveniently adjusted to provide optimum overlap of wavelength channels with the modulating channel spectra.

Abstract: Low optical loss and simplified fabrication are achieved by a nonlinear reflector which incorporates one or more semiconductor quantum wells within a standard semiconductor quarter wave stack reflector. The nonlinear reflector provides an intensity dependent response which permits it to be used for saturable absorption directly in a main oscillating cavity of a laser. Saturation intensity of the nonlinear reflector and thereby related laser modelocking properties can be controlled by disposing the quantum well at a particular position in the reflector structure.

Abstract: The present invention provides an apparatus and method for high-density optical wavelength division multiplexing (WDM) using a single optical source. An optical wavelength division multiplexer in accordance with the present invention includes an optical source providing an optical pulse signal. A wavelength splitter separates the optical pulse signal spectrum into a plurality of channel signals at different wavelengths such that each channel signal may be separately modulated or otherwise processed. A wavelength combiner then recombines the separately modulated channel signals to provide a high-density WDM optical signal particularly well-suited for use in optical circuit interconnection and optical communication network applications. The high-density single-source multiplexer of the present invention may also be conveniently adjusted to align channel signal wavelengths or to compensate for optical fiber dispersion.

Abstract: Photocurrent suppression is achieved without deleteriously affecting modulation performance in a surface normal, electro-absorption, quantum well modulator by introducing a sufficient number of non-radiative recombination centers in the quantum well region of the modulator. The presence of the non-radiative recombination centers significantly shortens the lifetime of photogenerated carriers and, thereby, suppresses the photocurrent. Modulation performance characteristics such as contrast ratio are maintained at acceptable levels even though exciton broadening occurs in the quantum wells. The present modulator exhibits a careful balance between defect density in the quantum wells and the acceptable degree of exciton broadening necessary to preserve quantum effects.

Abstract: Conventional microfabrication techniques in conjunction with the precise growth of layers of single crystalline materials by epitaxial growth techniques allow the creation of electro-optic microstructures which achieve high reflectivity with only few periods of layer pairs. Standard lithographic techniques are utilized to fabricate quantum wells which are confined on both sides by air, acrylic resin, or vacuum. The quantum wells are fabricated from spatially and compositionally modulated III-V superlattices in which alternate layers of the structures are sacrificed by selective etching. The structures are patterned such that the quantum wells are suspended between support posts.

Abstract: Apparatus is disclosed for generating two streams of optical pulse signals having less than 100 femtoseconds of jitter. A Ti:sapphire laser that is self mode locked by using self focusing in the gain medium and a weak HITCI intercavity dye jet for starting generates a first stream of substantially 100 femtosecond pulses. This first stream of optical pulses is split into two parts, one of which is used as a desired stream of optical pulses and the other of which is used to pump an HITCI dye laser synchronously to generate a second desired stream of optical pulses. The pulses of the second stream from the dye laser have durations of about 140 femtoseconds and less than 100 femtoseconds of jitter relative to the pulses of the first stream.

Abstract: Modelocking of a solid state laser such as a Ti:Al.sub.2 O.sub.3 laser is achieved by employing an external cavity defined by spatially separated reflective elements wherein at least one of the reflective elements exhibits a nonlinear characteristic in response to an impinging light beam. Exemplary nonlinear reflective elements are described using bulk semiconductor material or semiconductor quantum well structures integrated with a rear reflector such as a stack of quarter-wave thick dielectric or semiconductor material. Tuning control of the nonlinear reflective element may be introduced with temperature control arrangements and with mechanical translation arrangements in conjunction with lateral band gap engineering of the semiconductor material.

Abstract: An electro-optic medium, useful for image processing, is formed by creating a distribution of deep impurity levels over essentially all the lateral extent of a multilayer heterostructure. This treatment renders the heterostructure semi-insulating, and as a consequence, individual image-resolution elements are isolated. Described is an optical system comprising such an electro-optic medium.

Abstract: An electrooptic measuring apparatus having both high voltage sensitivity and femtosecond time resolution includes coplanar transmission lines fabricated on a semi-insulating multiple quantum well structure. An electrical signal, such as from a high speed electronic device, injected onto the transmission lines creates an electrical field parallel to the layer planes of the multiple quantum well structure. Excitonic electroabsorption by the multiple quantum well structure, in response to the parallel field, changes the transmissivity of the multiple quantum well structure. An external light beam directed through the multiple quantum well structure is modulated by the changes in transmissivity. By detecting this modulation, a sampling of the electrical signal is achieved.

Abstract: An inexpensive, simple and highly accurate sweep drive circuit for streak cameras generates a ramp voltage for the deflection plates of an image converter tube of a streak camera. A solid state switch is used in a manner which eliminates the need for a pulsed multi-kilovolt bias voltage and the use of cryogenics. High voltage direct current in the multi-kilovolt range is applied to a charged circuit which may include a high voltage capacitor or use the capacitance presented by the deflection plates of the tube. The switch is laser activated and becomes photo-conducting. The charge in the capacitor passes through a charging resistor which controls the sweep rate to the deflection plates. After the activating laser pulse, the switch returns rapidly to a nonconducting state, during the recombination time of the switch material. The photo-electron beam is swept linearly over a substantial portion of the recombination time from off the image forming phosphor screen to off screen on the other side thereof.