Princeton Lightwave, Inc.

Lucent Technologies Inc.

At+t Corp.

Amplification Technologies, Inc.

Jds Uniphase Corporation

Princeton Lightware, Inc.

Rafael Ben-Michael

Mark Itzler

Uziel Koren

Robert Bennett

Robert Raymond Miller, Ii

Sabbir Sajjad Rangwala

Anatoly A Tsaliovich

Theodore P Jamer

Xudong Jiang

Steven Kwan

Disclosed herein are avalanche photodiodes (APDs) particularly useful for high-sensitivity Geiger-mode APDs formed using an array of micro-cells. The photodetector is formed on a semiconductor substrate of indium phosphide (InP) having epitaxial layers, including indium gallium arsenide (InGaAs) as the photodetecting layer, with n-doped InP to one side, and layers of InP incorporating p-doped regions on the opposite side. The p-doped regions may serve to define an array of micro-cells, which may be arranged in a hexagonal pattern. A well may be etched through the epitaxial structures, allowing an electrode that contacts the n-doped InP layer and another that contacts the p-doped InP regions to be patterned on the same side of the detector. Flip-chip bonding techniques can then attach the semiconductor wafer to a stronger support substrate, which may additionally be configured with electronic circuitry positioned to electrically contact the electrodes on the semiconductor wafer surface.

High-sensitivity avalanche photodetectors

This Application discloses methods for fabricating and packaging avalanche photodiodes (APDs), particularly useful for high sensitivity Geiger-mode APDs formed using an array of micro-cells. The photodetector is formed on a semiconductor wafer of indium phosphide (InP) having epitaxial layers, including indium gallium arsenide (InGaAs) as the photodetecting layer, with n-doped InP to one side, and layers of InP incorporating p-doped regions on the opposite side. The p-doped regions may be used to define the array of micro-cells. The photodetector is packaged by etching a well into the epitaxial structure on the semiconductor wafer, allowing an electrode to be patterned that contacts the n-doped InP layer and another that contacts the p-doped InP regions. Flip-chip bonding techniques can then attach the semiconductor wafer to a stronger support substrate, which may additionally be configured with electronic circuitry positioned to electrically contact the electrodes on the semiconductor wafer surface.

Method for fabricating high-sensitivity photodetectors

A method for controlling dopant diffusion is disclosed. Using certain control parameters that are not used in the prior art, the method provides an unprecedented measure of control over the dopant diffusion process. The control parameters include, among others, the size of the diffusion windows in the diffusion mask and the proximity of the diffusion windows to a dopant sink. In some embodiments, the diffusion process is conducted in an epi-reactor.

Method for dopant diffusion

A single-photon detector is disclosed that provides reduced afterpulsing without some of the disadvantages for doing so in the prior art. An embodiment of the present invention provides a stimulus pulse to the active area of an avalanche photodetector to stimulate charges that are trapped in energy trap states to detrap. In some embodiments of the present invention, the stimulus pulse is a thermal pulse.

Apparatus comprising a single photon photodetector having reduced afterpulsing and method therefor

Avalanche photodiodes are provided, wherein the APDs provide both high optical coupling efficiency and low dark count rate. The APDs are formed such that their cap layer has an active region of sufficient width to enable high optical coupling efficiency but the APD still exhibits a low dark count rate. These cap layers have a device area with an active region and an edge region, wherein the size of the active region is substantially matched to the mode-field diameter of an optical beam, and wherein the size of the edge region is made small so as to reduce the number of defects included. These APD designs maintain a substantially uniform gain and breakdown voltage, as necessary for practical use.

Apparatus comprising an avalanche photodiode

Methods for fabricating an avalanche photodiode (APD), wherein the APD provides both high optical coupling efficiency and low dark count rate. The APD is formed such that it provides an active region of sufficient width to enable high optical coupling efficiency and a low dark count rate. Some APDs fabricated using these methods have a device area with an active region and an edge region, wherein the size of the active region is substantially matched to the mode-field diameter of an optical beam, and wherein the size of the edge region is substantially minimized and further wherein the device region maintains a substantially uniform gain and breakdown voltage.

Method for forming an avalanche photodiode

A highly reflecting back illuminated diode structure allows light that has not been absorbed by a semiconductor absorbing region to be back reflected for at least a second pass into the absorbing region. The diode structure in a preferred embodiment provides a highly reflecting layer of gold to be supported in part by a conducting alloyed electrode ring contact and in part by a passivation layer of SiN. Conveniently this structure provides a window within the contact which allows light to pass between the absorbing region and the reflecting layer of gold.

Back illuminated photodiodes

A new communication distribution platform for a customer premise creates a new paradigm where components from the physical layer are shared, components from the MAC layer are shared, and a common network layer is used. A single modulation unified system and shared MAC is used across multiple media. Varied implementations may chose to share only physical layer components, or MAC layer components, or both. One implementation disclosed is the use of a common physical layer modulation combined with a MAC layer with many common functions in support of delivery of IP based services within the premises. This combination optimizes customer experience, flexibility in use, provides simpler maintenance, and simpler reduced inventory requirements and operations support for service suppliers. It can be used to support either a circuit switched environment or packet switched environment.

Universal premises distribution platform

A method of identifying and communicating the existence of Intermittent nodes in a communication network with a mixed TDMA/CSMA-CD MAC frame format, and of preventing these nodes from unnecessarily debasing existing voice channel connections. Information pertaining to intermittent nodes is included in a database for an extended operational duration and used as primary information in control of the creation of any newly requested voice channels. Intermittent nodes are treated for the purpose of assigning voice channels as existing permanent nodes, whether currently visible or not. Newly revealed intermittent nodes are added to the database through intermediate nodes. This invention increases reliability and quality of voice communications during noise/impedance level changes of the network that may render one or more nodes not visible.

Intermittent node resolution for voice and data communication system

A method and apparatus improves transmission quality of transmission media in a punctuated noise environment by terminating transmission during duration of punctuated large noise changes and alters network parameters, of the transmission media, to accommodate changes in level of stable noise conditions between punctuated large noise changes. Each stable noise level encountered is measured and its characteristics (i.e., level) is stored in a data base and associated network parameters (i.e., bit rates, bandwidth etc.) are changed accordingly and used to control or maintain quality of the transmission media.

Control of broadband voice and data communication over a low quality noisy transmission media

An integrated light-emitting device has a laser section and a detector section. The laser section and the detector section have an active layer that is integrated along an in-line waveguide. The detector section also has a bulk layer adjacent to the active layer, where the bulk layer has a band gap energy lower than the band gap energy of the active layer. In one embodiment, the active layer is an multiple quantum well (MQW) layer, the waveguide has two quaternary layers, and the bulk layer is a bulk quaternary layer. The device, which has uncooled modes of operation for both transmitting and receiving, may be used as a transceiver in a ping-pong optical data link configuration. The device may also have a beam expander section, with the laser, detector, and beam expander sections inside a Fabry-Perot cavity, along the single in-line waveguide. In one embodiment having a 1.3 .mu.m lasing wavelength, the addition of a 1.4 .mu.m bulk quaternary layer provides the detector with a broad spectral responsivity range extending 33 nm higher than the lasing wavelength of the device. This permits uncooled operation of the device with sufficient response even in the most severe temperature scenarios that would typically occur. The transmitter can provide 8 dBm inside a single mode fiber, and the beam expander relaxes the alignment tolerance, using a cleaved rather than a lensed single mode fiber.

Detector for photonic integrated transceivers

The present invention is directed to a semiconductor waveguiding structure which includes a) a first semiconductor waveguiding layer formed on a substrate, b) a barrier layer that is formed on the first semiconductor waveguiding layer, and that is resistant to a selected etchant, and c) a second semiconductor waveguiding layer that is etched using the selected etchant such that its width is tapered along its length to a pointed edge. A separate etching of the first semiconductor layer is performed to form each sidewall of the first semiconductor layer. The intersection of those sidewalls defines the pointed edge which has a radius of curvature of less than 500 Angstroms.

Growing community of inventors

Scotch Plains, NJ, United States of America

Rafael Ben-Michael