Discovery Semiconductors, Inc.

Epitaxx, Inc.

Abhay M Joshi

Shubhashish Datta

Donald A Becker

Daniel R Mohr

Christoph T Wree

Suhas P Bhandare

Krishna R Linga

A pseudo-random sequence generator for use within a universal lidar system and its corresponding method of operation. The pseudo-random sequence generator uses synchronized shift registers that are in series Binary adders are provided. The signal output of each of the shift registers is tapped and directed to the binary adders. High-speed switches are provided between the shift registers and the binary adders. The switches are programmed to connect only two of the shift registers to the binary adders for each of the pseudo-random patterns being generated. The binary adders generate an output signal that is received by the first shift register. The signal propagates through all the shift registers to the last shift register. The last shift register outputs a pseudo-random sequence.

Programmable pseudo-random sequence generator for use with universal lidar and its associated method of operation

A lidar system where a laser creates a laser output and the sequence generator creates a pseudorandom noise sequence. The laser output is directed into two paths. On the first path, the laser output is directed to a first modulator. The first modulator encodes the laser output with the pseudorandom noise sequence to produce an encoded output signal. The encoded output signal is amplified and directed toward a target, wherein a back-scattered signal is reflected back from the target. On the second path, the laser output is directed to a second modulator. The second modulator modulates the laser output to produce an oscillator signal. The back-scattered signal is aligned and is mixed with the oscillator signal from the second modulator. The resulting mixed signal is converted into a corresponding RF output signal. The RF output signal is cross-correlated with the pseudorandom noise sequence to acquire target data.

System and method for improving the resolution and sensitivity of lidar

A quad photoreceiver includes a low capacitance quad InGaAs p-i-n photodiode structure formed on an InP (100) substrate. The photodiode includes a substrate providing a buffer layer having a metal contact on its bottom portion serving as a common cathode for receiving a bias voltage, and successive layers deposited on its top portion, the first layer being drift layer, the second being an absorption layer, the third being a cap layer divided into four quarter pie shaped sections spaced apart, with metal contacts being deposited on outermost top portions of each section to provide output terminals, the top portions being active regions for detecting light. Four transimpedance amplifiers have input terminals electrically connected to individual output terminals of each p-i-n photodiode.

Low-noise large-area photoreceivers with low capacitance photodiodes

Repeaterless transmission of differential phase-shift keying (DPSK) at 10.7 Gb/s over at least 304 km of standard single-mode fiber is obtained through use of a coherent optical receiver including electronic dispersion compensation. High receiver sensitivity and high tolerance to nonlinearities of DPSK, allow overcoming a total link loss of 58 dB with a 3 dB system margin, through use in the receiver of heterodyne detection to preserve phase distortions resulting from chromatic dispersion, to permit electronic dispersion compensation to be used.

Method and apparatus for repeaterless high-speed optical transmission over single-mode fiber using coherent receiver and electronic dispersion compensation

An optical coherent receiver in one embodiment has a heterodyne configuration, and in another embodiment has a homodyne configuration, in each configuration employs multiple feedback signaling and analog/digital processing to optimize response to a modulated optical input signal, the provision of both individual RF I and RF Q channel outputs.

Feedback-controlled coherent optical receiver with electrical compensation/equalization

A plurality of silicon and GaAs wafers each including integrated circuitry for providing particular functions for each wafer are mounted within a housing in a stacked, spaced apart, and parallel configuration. Photodetectors and LED's are used to transmit and receive data between opposing wafers. In this manner a micro-packaged device or system is obtained for use amongst other things in lightweight miniaturized microsatellites.

Lightweight miniaturized integrated microsatellite employing advanced

A monolithic Optoelectronic Integrated Circuit including a photodiode and a CMOS readout circuit is described in which the diode is formed by compositionally graded layers of In.sub.x Ga.sub.1-x As selectively epitaxially grown between a substrate of Si and an absorption layer of In.sub.x Ga.sub.1-x As, the areas of said layers being less than 500 .mu.m.sup.2 and wherein a readout circuit on said substrate is coupled to said diode.

Method and apparatus for monolithic optoelectronic integrated circuit

Leakage current in InGaAs/InAsP/InP lattice mismatched photodetectors can be reduced by providing graded InAsP compositions having abrupt interfaces between successive layers that maintain a lattice mismatch between the layers of 0.13% or less; doping the absorption layer with high levels of sulfur and by thermal cycling of the wafers. High yields of low leakage current photodetector arrays are obtained.

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New Hope, PA, United States of America

Abhay M Joshi