Abstract: A narrowband laser source includes an optical fiber section including a core centered on a longitudinal axis and a cladding surounding the core, and having a grating region embedded in the core. The grating region includes a multitude of Bragg grating elements extending with a substantially equal longitudinal spacing substantially normal to the longitudinal axis for the grating region to significantly reduce the amount of light passing therethrough when the frequency of such light is in a predetermined narrow range around and including a predetermined center frequency, to an extent proportionate to the deviation of such frequency from the center frequency. A portion of the light emitted by a laser at a frequency dependent on the amount of electric energy applied to the laser is supplied into the core of the fiber section for propagation toward the grating region.

Abstract: A single polarization active IO device includes a crystalline material substrate having an IO circuit array comprising an optical waveguide array disposed on a major surface of the substrate by a two step proton exchange (TSPE) process, and including an electrode array disposed on the major surface in juxtaposed relation with the waveguide array to provide one or more active IO regions thereon.

Abstract: An optical power star coupler includes a LiNbO.sub.3 or LiTaO.sub.3 substrate having a major surface for receiving a circuit array of one or more surface for splitters disposed thereon by a two step proton exchange (TSPE) process, in a geometric pattern to provide an N.times.M star coupler having high polarization extinction, uniform splitting ratio, and low loss.

Abstract: Spatial light modulators which use a substrate having a buried channel charge-coupled device (CCD) formed therein, wherein the amount of charge in the charge storage wells associated with the electrodes of the CCD is controlled by an electrically or optically addressed data signal. The level of charge in such charge storage wells controls the electric field beneath the electrodes so that the intensity of electromagnetic energy (e.g., light) directed through The CCD is spatially modulated by the charge levels in the charge storage wells in accordance with the Franz-Keldysh electroabsorption effect.

Abstract: Discrete segments of an analog optical wave signal are collected in individual waveguides of a waveguide array. In the waveguide array, the optical signal is processed to provide an analysis of the signal or to control the signal. The signal can be analyzed by Mach-Zehnder interferometers which can provide an indication of the distance of a subject from the array. By controlling the dielectric constants of the waveguides electronically, the array can serve as an aberration free focusing lens or as an aberration compensation lens. Rapid electronic control of the focal length of the lens makes the lens particularly applicable to automatic focusing systems, systems which view only objects within a selected range of distances from the array, and the compiling of in focus segments to form a wide depth of field image.

Abstract: Spatial light modulators which use a substrate having a buried channel charge-coupled device (CCD) formed therein, wherein the amount of charge in the charge storage wells associated with the electrodes of the CCD is controlled by an electrically or optically addressed data signal. The level of charge in such charge storage wells controls the electric field beneath the electrodes so that the intensity of electromagnetic energy (e.g., light) directed through the CCD is spatially modulated by the charge levels in the charge storage wells in accordance with the Franz-Keldysh electroabsorption effect.

Abstract: An electronic mixer is decribed which utilizes an optoelectronic switch formed from a semi-insulating substrate of indium phosphide doped with a deep level impurity and disposed intermediate a microstrip transmission line. One conductor of the transmission line has a small gap in its metallization. Upon illumination of the gap by laser pulses from a laser source which are absorbed near the semiconductor surface, a photo-generated electron-hole plasma forms thereby providing a conducting path across the gap. An RF signal to be mixed with a LO signal is coupled to one side of the switch. The LO signal controls the Laser source. The output of the switch is therefore the product of the RF and LO signal.

Abstract: A three-dimensional optical waveguide is disclosed. This waveguide comprises a single crystal semiconductor layer grown upon an insulator which has an index of refraction lower than the semiconductor. The semiconductor layer has a thickness which provides confinement of light propagating in the semiconductor layer in the vertical direction. An effective larger index of refraction over a cross-sectional region of the semiconductor layer provides confinement of light in the lateral direction. This lateral confinement is achieved by side walls in the semiconductor layer which extend toward, but fall short of, the insulator layer.

Abstract: A high speed sampling technique is proposed using a cascade of optical waveguide interferometers driven by CW sinusoidal traveling or standing microwaves. Each interferometer multiplies the optical signal by a function closely approximated by cos.sup.4 .omega.t, where .omega. is the frequency of its microwave drive. A cascade of four interferometers with 2.6 V microwave drives at 10, 20, 40, and 80 GHz and a total length of 2 cm can sample an optical signal with 2 ps resolution and 50 ps between samples.

Abstract: A method for fabricating three-dimensional optical waveguides is disclosed. In this method, a single crystal semiconductor layer is grown upon an insulator which has an index of refraction lower than the semiconductor. The semiconductor layer is deposited to a thickness which provides confinement of light propagating in the semiconductor layer in the vertical direction. An effective larger index of refraction over a cross-sectional region of the semiconductor layer is then formed to provide confinement of light in the lateral direction. In the preferred method, the growth of single crystal semiconductor upon the insulator is achieved by a vapor-phase lateral epitaxial overgrowth technique.Devices fabricated according to the method are also disclosed.

Abstract: An optoelectronic switch has been formed from a semi-insulating substrate of indium phosphide doped with a deep level impurity and disposed intermediate a microstrip transmission line. One conductor of the transmission line has a small gap in its metallization. Upon illumination of the gap by laser pulses which are absorbed near the semiconductor surface, a photogenerated electron-hole plasma forms thereby providing a conducting path across the gap turning the switch "on."A process of fabricating the switch is described, an important feature of which is a heat-treatment process which improves the response time of the switch to .about.50 picoseconds. Another important part of the invention is the formation of an optically semi-transparent metallic film at the gap surface. This provides greater efficiency in the coupling of light into the device at the gap while at the same time maintaining a short electronically non-conductive gap and thus a relatively low ON-state impedance for the switch.

Abstract: A planar semiconductor optical waveguide, modulator, variable coupler and switch are described. The waveguide has an epitaxial layer on a semiconductor substrate. Two spaced strips of opposite conductivity type are implanted in the layer to form an optical waveguide channel in the space. By closely spacing two waveguide channels so that they have a common strip and a strip outside each channel, coupling is obtained between the channels. For a switch, the coupling length is such that substantially all the optical energy in the input channel is coupled to and emerges from the other channel. Reverse biasing one of the outside strips causes the optical energy to divide between the input channel and the output channel to provide output power modulation or variable coupling, and substantially complete transfer of power (switching) for a particular value of reverse bias.