Opnext Subsystems, Inc.

Oclaro Inc.

Sunil Kumar Singh Khatana

Edem Ibragimov

Bo Zhang

Lee Dardis

Hong Jiang

George Zarris

A coherent optical receiver measures a portion of a spectra of a multi-channel optical signal that includes at least one signal adjacent to a selected signal. The coherent optical receiver determines structure and bandwidth information for the measured portion of spectra, and determines one or more filter parameters for the selected signal based on the structure and bandwidth information of the at least one signal adjacent to the selected signal. The coherent optical receiver adjusts one or more active filter parameters of a carrier phase estimator in the optical coherent receiver to have values corresponding to the determined one or more filter parameters.

Spectral analysis for coherent optical receivers

Feed-forward and feedback strategies are used to control local oscillator power and transimpedance amplifier gain in a high-speed coherent optical receiver.

Automatic gain control for high-speed coherent optical receivers

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 &#x3c0;, 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.

Alignment of in-phase and quadrature data in quadrature phase shift keying optical transmitters

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.

Polarization and differential-group-delay insensitive digital timing error detection for polarization-multiplexed coherent optical systems

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.

Multiplexer lane alignment for high-speed data systems

A method for detecting and measuring time skew in high-speed DP-QPSK coherent optical receivers is described.

Quadrature time skew detection for coherent optical signals

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 &#x3c0;, 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.

Growing community of inventors

Sunnyvale, CA, United States of America

Sunil Kumar Singh Khatana