Bell Telephone Laboratories

University of Virginia Patent Foundation

Other

The University of Texas System

At&t Bell Laboratories

The University of Chicago

Joe C Campbell

Tien P Lee

Scott J Maddox

Seth Bank

Julian Stone

Andrew Gomperz Dentai

John C Bean

Yaojia Chen

Boris Gelmont

Tatiana Globus

Charles A Burrus, Jr

Ping Yuan

Andrew G Dentai

Kam-Yin Lau

Supratik Guha

Pineas Paxton Marshall

Lloyd Harriott

Naser Alijabbari

Min Ren

Madison Woodson

Wenlu Sun

William Allsup

Jiyuan Zheng

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.

Avalanche photodiodes with adaptive quenching of photocurrent

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 &#x3bc;m, and preferably an average thickness of 0.5 to 0.6 &#x3bc;m. The chalcogenide salt layer is a lead chalcogenide, such as a nanocrystaline lead sulfide, nanocrystalline lead selenide, or a nanocrystalline lead telluride.

Thin film photovoltaic cell system and method of manufacture

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.

AllnAsSb avalanche photodiode and related method thereof

A staircase avalanche photodiode with a staircase multiplication region composed of an AlInAsSb alloy. The photodiode includes a buffer layer adjacent to a substrate and an avalanche multiplication region adjacent to the buffer layer, where the avalanche multiplication region includes a graded AlInAsSb alloy grown lattice-matched or psuedomorphically strained on either InAs or GaSb. The photodiode further includes a photoabsorption layer adjacent to the avalanche multiplication region, where the photoabsorption layer is utilized for absorbing photons. By utilizing AlInAsSb in the multiplication region, the photodiode exhibits a direct bandgap over a wide range of compositions as well as exhibits large conduction band offsets much larger than the smallest achievable bandgap and small valance band offsets. Furthermore, the photodiode is able to detect extremely weak light with a high signal-to-noise ratio.

Staircase avalanche photodiode with a staircase multiplication region composed of an AIInAsSb alloy

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.

Avalanche photodiodes with an impact-ionization-engineered multiplication region

A new vehicle mirror viewing system which is designed for rear view mirrors mounted exteriorly of a vehicle and allows a driver to either view the mirror or an image transmitted from the mirror to a viewing screen mounted interiorly of the vehicle. A fiber optic transmission cable is utilized in conjunction with a two-way mirror to transmit the reflected image from the mirror to the viewing screen. The cable utilizes a large bundle of fiber optic cables, and the ends of the cables are mounted in small blocks which allow only small pixels of light to be transmitted from an image passes through the two-way mirror. With the ends of the cables mounted in arrays within transducers, a composite image can be transmitted from a rear surface of the rear view mirror to the viewing screen.

Safety vehicle mirror viewing system

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).

Long wavelength avalanche photodetector

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. By reversing the dc potential applied to the junctions in the quaternary layers, a dual-wavelength light emitting diode is provided.

Demultiplexing photodetectors

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.

Demultiplexing photodetector

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.

Magneto-optic modulator using dielectric mirrors

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. By reversing the dc potential applied to the junctions in the quaternary layers, a dual-wavelength light emitting diode is provided.

Growing community of inventors

Charlottesville, VA, United States of America

Joe C Campbell