Abstract: Avalanche photodiode designs having separate absorption and multiplication regions are disclosed. The avalanche photodiode designs include a charge layer tailored to allow charge carrier transport from the absorption layer to the multiplication layer and reduce the dark current when the avalanche photodiode is reverse biased.

Abstract: This disclosure is directed to a high-speed avalanche photodiode device configured to detect single photons. The avalanche photodiode device may include a passive quenching circuitry. The passive quenching circuitry may include a quenching resistor having a resistivity spontaneously adaptive to a bias voltage applied across the quenching resistor. Such adaptive resistivity enables a fast response time for the avalanche photodiode device when used to detect single photos in Geiger mode.

Abstract: A photovoltaic structure for absorption from the solar spectrum, includes a light transmitting substrate layer, a transparent electrode layer on the substrate layer, a direct band-gap, wide band-gap, nanocrystalline or microcrystalline, think film semiconducting first layer on the transparent electrode layer, a second think film layer comprising a narrow band-gap semiconductor on the first layer a second electrode layer on the second think film layer, and a protective layer on the second electrode layer. The structure has a hetero-structure at the boundary between the wide-band-gap layer and the second thin film layer. The second layer can be chalcogenide salt having an average thickness of 0.4 to 1.2 ?m, and preferably an average thickness of 0.5 to 0.6 ?m. The chalcogenide salt layer is a lead chalcogenide, such as a nanocrystaline lead sulfide, nanocrystalline lead selenide, or a nanocrystalline lead telluride.

Abstract: An avalanche photodiode, and related method of manufacture and method of use thereof, that includes a first contact layer; a multiplication layer, wherein the multiplication layer includes AlInAsSb; a charge, wherein the charge layer includes AlInAsSb; an absorption, wherein the absorption layer includes AlInAsSb; a blocking layer; and a second contact layer.

Abstract: An avalanche photodiode, and related method of manufacture and method of use thereof, that includes a first contact layer; a multiplication layer, wherein the multiplication layer includes AlInAsSb; a charge, wherein the charge layer includes AlInAsSb; an absorption, wherein the absorption layer includes AlInAsSb; a blocking layer; and a second contact layer.

Abstract: The monolithic application of a high speed TWPDA with impedance matching. Use of the high speed monolithic TWPDA will allow for more efficient transfer of optical signals within analog circuits and over distances.

Abstract: A method and semiconductor device for integrating the fabrication of a photodetector with the fabrication of a CMOS device on a SOI substrate. The SOI substrate is divided into two regions, a CMOS region and an optical detecting region. After the CMOS device is fabricated in the CMOS region, the optical detecting region is patterned and etched through the top silicon layer and the buried oxide layer to the base silicon layer. The pattern is etched to a depth so that after a material of a photodetector is deposited in the etched pattern, the material grows to the surface level of the SOI substrate. After the formation of a photodetector structure in the optical detecting region, the metallization process is performed on the CMOS device and the photodetector. In this manner, the fabrication of a photodetector is integrated with the fabrication of a CMOS device on the SOI substrate.

Abstract: An avalanche photodiode including a multiplication layer is provided. The multiplication layer may include a well region and a barrier region. The well region may include a material having a higher carrier ionization probability than a material used to form the barrier region.

Abstract: An avalanche photodiode including a multiplication layer is provided. The multiplication layer may include a well region and a barrier region. The well region may include a material having a higher carrier ionization probability than a material used to form the barrier region.

Abstract: High speed, high quantum efficiency, low dark current, and avalanche gain greater than 10 are exhibited by a long wavelength avalanche photodetector including in succession a terminal region of p-type indium phosphide (InP) a multiplication region comprising first and second layers of n-type indium phosphide (InP), a grading layer of n-type indium gallium arsenide phosphide (InGaAsP), and an absorption region of n-type indium gallium arsenide (InGaAs).

Abstract: A 3-terminal totally integrated demultiplexing photodiode is disclosed wherein information present simultaneously at two wavelengths can be developed into two separate currents available at the three terminals. Two quaternary n-type layers (103 and 105) of indium gallium arsenide phosphide having unequal bandgaps and each having a pn junction are separated by a layer (104) of n-type indium phosphide. The device is oriented so as to present the incoming radiation first to the quaternary layer having the larger bandgap and then to the quaternary layer having the lower bandgap. One of the contacts (111) is attached to the top layer (106) of n-type indium phosphide, a second contact (112) is attached to a central p-type region (110) established in the top layer of indium phosphide and penetrating through the top quaternary layer, and the third contact (113 or 302) is connected either to the indium phosphide substrate (101) or to a p-type outer region (301) that surrounds all of the layers.

Abstract: A three terminal, totally integrated demultiplexing photodiode is disclosed wherein information present simultaneously at two wavelengths can be developed into two separate currents available at the three terminals. Two quaternary layers (203 and 205) of indium, gallium, arsenide phosphide having unequal bandgaps and each having a pn junction are separated by a buffer layer (204) of n type indium phosphide. Operation at longer wavelengths is achieved by causing the bottom quaternary layer to have the higher bandgap energy thereby permitting it to detect the shorter wavelengths in the radiation and causing the topmost quaternary layer (205) to have the lower bandgap energy thereby permitting it to detect the longer wavelengths. The bottom contact (213) on the substrate has an opening thereby providing a window (230) through which incoming radiation (250) can be coupled through the substrate to the two quaternary layers.

Abstract: A magneto-optic modulator of the bounce-cavity type is disclosed wherein the mirrors that are attached to the garnet crystal to provide the reflections are multilayered dielectric mirrors. By polarizing the input beam such that its E vector is perpendicular to the plane of incidence substantially total reflection is achieved from the mirrors and all of the input beam emerges from the garnet crystal. A metal film deposited on a plane of the crystal that is perpendicular to the mirrors permits the establishment of a magnetic field that is substantially parallel to the reflected beams within the crystal. When the field is established by passing current through the film, much of the light is lost during each of the reflections since substantial amounts of the polarized light having polarizations in the plane of incidence are coupled through the dielectric mirrors. Hence the intensity of the output beam is modulated by the current in the metal film.

Abstract: A 3-terminal totally integrated demultiplexing photodiode is disclosed wherein information present simultaneously at two wavelengths can be developed into two separate currents available at the three terminals. Two quaternary n-type layers (103 and 105) of indium gallium arsenide phoshide having unequal bandgaps and each having a pn junction are separated by a layer of (104) of n-type indium phosphide. The device is oriented so as to present the incoming radiation first to the quaternary layer having the larger bandgap and then to the quaternary layer having the lower bandgap. One of the contacts (111) is attached to the top layer (106) of n-type indium phosphide, a second contact (112) is attached to a central p-type region (110) established in the top layer of indium phosphide and penetrating through to the top quaternary layer, and the third contact (113 or 302) is connected either to the indium phosphide substrate (101) or to a p-type outer region (301) that surrounds all of the layers.

Abstract: This disclosure concerns optical waveguides of arcuate structure fabricated by selective liquid phase epitaxy. In integrated optical circuits requiring complex processing, it will be necessary to utilize at relatively low light losses bends, curves, and dividers in the waveguide section. The arcuate optical waveguides described herein have a region of higher index of refraction surrounded by lower effective index media to confine and propagate light between active components of an integrated optical circuit. Optical waveguides extending around bends are grown by selective liquid phase epitaxy employing a horizontal graphite boat with sliding compartments, wherein multiple layers of Ga.sub.1-x Al.sub.x As(0.ltoreq.x.ltoreq.0.3) are grown. For a relatively low radius of curvature where r.sub.c = 10 mils, the angle is dominated by a sharp facet, with the faceting slowly decreasing as the radius of curvature increases, until at r.sub.