Opnext Patent Applications

Optical Coherent Receiver Optimization

Granted: July 4, 2013
Application Number: 20130170829
Coherent optical receiver performance is optimized and made adaptable to changing optical channel conditions by providing feedback loops to adjust receiver parameters based on measured receiver performance.

Automatic Gain Control for High-Speed Coherent Optical Receivers

Granted: March 21, 2013
Application Number: 20130071109
Feed-forward and feedback strategies are used to control local oscillator power and transimpedance amplifier gain in a high-speed coherent optical receiver.

OPTICAL SEMICONDUCTOR DEVICE, AND MANUFACTURING METHOD THEREOF

Granted: December 20, 2012
Application Number: 20120321244
The optical semiconductor device includes a spot-size converter formed on a semiconductor substrate. The spot-size converter has a multilayer structure including a light transition region. The multilayer structure includes a lower core layer, and an upper core layer having a refractive index higher than that of the lower core layer. The width of the upper core layer is gradually decreased and the width of the lower core layer is gradually increased in the light transition region. Both…

OPTICAL DEVICE, MODULATOR MODULE, AND METHOD FOR MANUFACTURING THE OPTICAL DEVICE

Granted: December 13, 2012
Application Number: 20120314725
An optical device includes a ridge-like optical waveguide portion, a mesa protector portion that is arranged in parallel to the optical waveguide portion, a resin portion that covers upper parts of the mesa protector portion and is disposed at both sides of the mesa protector portion, an electrode that is disposed on the optical waveguide portion, an electrode pad that is disposed on the resin portion located at an opposite side to the optical waveguide portion with respect to the mesa…

OPTICAL OUTPUT MODULE, OPTICAL TRANSCEIVER, AND OPTICAL TRANSMISSION SYSTEM

Granted: November 29, 2012
Application Number: 20120301153
The I phase modulator modulates a phase based on the bias voltage in which a first modulation signal and a first pilot signal are inherent and the Q phase modulator modulates a phase based on the bias voltage in which a second pilot signal different from the first pilot signal and a second modulation signal are inherent. A time-average power synchronous detection unit detects an optical power at a timing at which the positivity and negativity of the voltages of both pilot signals become…

LIGHT-RECEIVING DEVICE ALLAY, OPTICAL RECEIVER MODULE, AND OPTICAL TRANSCEIVER

Granted: November 22, 2012
Application Number: 20120292731
A light-receiving device array includes a photodiode array that is provided with plural light-receiving sections each of which includes a first conductivity type electrode and a second conductivity type electrode, and a carrier, wherein the carrier includes plural pair of electric lines each of which is formed from a first electric line connected to the first conductivity type electrode of each light-receiving section, and a second electric line connected to the second conductivity type…

OPTICAL PHASE SHIFTER AND DEMODULATOR

Granted: November 15, 2012
Application Number: 20120287497
An optical phase shifter according to the invention includes the thermo-optical element of which a refractive index with respect to an input optical signal changes dependently on temperature; a temperature change section, having contact with one end of the thermo-optical element and of which a temperature changes so that a temperature of the thermo-optical element becomes a desired temperature; a heat dissipation section being disposed on an opposite side of the thermo-optical element…

Polarization and Differential-Group-Delay Insensitive Digital Timing Error Detection for Polarization-Multiplexed Coherent Optical Systems

Granted: November 15, 2012
Application Number: 20120288275
Digital timing error detection systems and techniques are described. The described techniques are independent of polarization and differential-group-delay and are used to perform timing recovery of polarization-multiplexed coherent optical systems.

DIFFERENTIAL TRANSMISSION CIRCUIT AND INFORMATION PROCESSING SYSTEM

Granted: October 25, 2012
Application Number: 20120269522
A differential transmission circuit includes a grounded conductive layer, a pair of transmission line conductors, a conductive film and a via hole which connects the grounded conductive layer to the conductive film. The differential transmission circuit further includes a straight-line region which is present in the differential transmission circuit through which a differential transmission signal output by a driving circuit is transmitted and in which the pair of transmission line…

Alignment of In-phase and Quadrature Data in Quadrature Phase Shift Keying Optical Transmitters

Granted: October 4, 2012
Application Number: 20120250792
I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include streams of alternating ones and zeroes.

In-Phase and Quadrature Pattern Alignment for Quadrature Phase Shift Keying Optical Transmitters

Granted: October 4, 2012
Application Number: 20120250793
I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include pseudorandom streams of ones and zeroes.

Multiplexer Lane Alignment for High-Speed Data Systems

Granted: October 4, 2012
Application Number: 20120251099
Patterns detected by a low-speed receiver at the output of a high-speed multiplexer are used to determine when multiplexer input lanes are deskewed.

DIFFERENTIAL TRANSMISSION CIRCUIT, OPTICAL MODULE, AND INFORMATION PROCESSING SYSTEM

Granted: September 13, 2012
Application Number: 20120229998
A differential transmission circuit includes a pair of transmission line conductors and a ground conductor layer, wherein the pair of transmission line conductors include a first straight line region where both the pair of transmission line conductors extend in parallel to each other in a first direction with a first width in a first layer, a first cross region where one of the pair of transmission line conductors is formed in the first layer, the other thereof is formed in a second…

WAVELENGTH TUNABLE FILTER AND WAVELENGTH TUNABLE LASER MODULE

Granted: September 6, 2012
Application Number: 20120224594
A wavelength tunable filter and a wavelength tunable laser module are a codirectional coupler type whose characteristics do not vary significantly with a process error. They are structured so as to include a semiconductor substrate which has a first optical waveguide and a second optical waveguide. The first and the second optical waveguides are extended from a first side of the semiconductor substrate to an opposing second side thereof. The first optical waveguide includes a first core…

Quadrature Time Skew Detection for Coherent Optical Signals

Granted: September 6, 2012
Application Number: 20120224847
A method for detecting and measuring time skew in high-speed DP-QPSK coherent optical receivers is described.

OPTICAL RECEIVER

Granted: July 26, 2012
Application Number: 20120189299
In pattern synchronization for correctly regenerating received data, which is performed in an optical receiver for receiving an optical signal that has been subjected to quadrature phase modulation, signal conduction is quickly established without using duplicate combinations of bit shifting and pattern changing. A control method that does not involve verifying the duplicate combinations generated in modulation formats and pattern synchronization search orders. Specifically, a signal…

INTERFEROMETER, DEMODULATOR AND RECEIVER-TRANSMITTER

Granted: July 19, 2012
Application Number: 20120182559
A delay interferometer includes a half beam splitter and two pentagonal prisms disposed on a substrate. The half beam splitter branches light to be measured which travels substantially in parallel with the substrate into two branched light beams. The pentagonal prisms respectively reflect the respective branched light beams such that the optical axes of the branched light beams are moved in parallel in a direction substantially perpendicular to the substrate by reflection. The half beam…

OPTICAL MODULE

Granted: May 24, 2012
Application Number: 20120128300
Provided is an optical module, including: an optical system having an optical path in a space thereof; an electro-optical device optically connected to a first input/output port as one of an input port and an output port of the optical system; an optical waveguide having flexibility; and a housing including an optical interface. The optical waveguide includes: a first connection portion optically connected to the optical interface in the housing; and a second connection portion optically…

Polarization Monitoring in Polarization Division Multiplexing in Optical Communications

Granted: January 26, 2012
Application Number: 20120020659
Systems and techniques for optical communications based on polarization division multiplexing are described.

SEMICONDUCTOR OPTICAL DEVICE, OPTICAL TRANSMITTER MODULE, OPTICAL TRANSCEIVER MODULE, AND OPTICAL TRANSMISSION EQUIPMENT

Granted: January 12, 2012
Application Number: 20120008895
Provided is a semiconductor optical device, which has a buried heterostructure structure and is formed in a structure capable of reducing a parasitic capacitance to further improve characteristics thereof, and also provided are an optical transmitter module, an optical transceiver module, and an optical transmission equipment. The semiconductor optical device includes a modulator portion for modulating light input along an emitting direction and radiating the modulated light, the…