Finisar Corporation

Optium Corporation

Terence D Grenda

Heider Naim Ereifej

John J DeAndrea

Suhas P Bhandare

Mark Colyar

Stephen Bradley Krasulick

Paul Kit Lai Yu

David Meloche

Chris Stook

Paul Yu

Embodiments include a method and apparatus used for automatic bias stabilization of a DP IQM based on MZM for transmitting DP-QPSK optical data and/or DP-16QAM optical data. The apparatus simultaneously dithers DC-bias voltages of in-phase child, quadrature-phase child, and parent MZMs with three different dither patterns in time-domain which are mutually orthogonal to each other in the frequency-domain for X and Y polarization IQ modulators. Tap monitor photodiodes detect an interference term between these three dither patterns for each polarization. The interference term is sampled using an ADC in the time domain. The time-synchronous detection method may solve a set of three simultaneous linear partial differential equations with three unknowns to compute controlled DC-bias voltages to set on the respective MZM with a solution set which may iteratively converge to a unique solution, thereby biasing the child MZM in dual-polarization IQM to transmission minimum and parent MZM in quadrature transmission.

Automatic bias stabilization of dual-polarization in-phase and quadrature optical modulator

An electra-absorption modulator and electra-absorption modulated laser are described that include a semiconductor layer having an electrically controllable absorption. The material composition of the semiconductor layer is chosen so that the semiconductor layer is substantially transparent to light propagating through the semiconductor layer when a substantially zero or a reverse bias voltage is applied across the semiconductor layer at operating temperatures of the electro-absorption modulator that are substantially greater than 25 degrees Celsius.

Electro-absorption modulated laser with high operating temperature tolerance

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Perkasie, PA, United States of America

Terence D Grenda