Elenion Technologies, LLC

Nokia Solutions and Networks Oy

Robert Palmer

Matthew Streshinsky

Torsten Wuth

Guido Saathoff

Thomas Wetteland Baehr-Jones

Bernd-Harald Horst Jurgen Rohde

Kishore Padmaraju

Marc Bohn

Ruizhi Shi

Torsten Wuth-Brüning

An optical waveguide modulator with automatic bias control is disclosed. A dither signal is applied to the modulator bias and its signature detected in light tapped from an output of the modulator using a phase sensitive dither detector such as a lock-in amplifier. The detected signal is processed using pre-recorded information defining the direction of the detected signal change relative to a change in the modulator bias, and the bias is adjusted in the direction determined using the information. An IQ bias of a quadrature modulator is controlled by dithering bias settings of two inner modulators at different dither frequencies, and detecting an oscillation at a sum frequency.

Bias control of optical modulators

A transceiver having an improved transmitter optical signal to noise ratio, and methods of making and using the same.

Transmitter optical signal to noise ratio improvement through receiver amplification in single laser coherent systems

A photonic integrated circuit for an optical transceiver includes an optical Rx circuit, an optical Tx circuit, and an integrated optical loopback circuit configured to switchably direct a loopback optical signal from an output of the optical Tx circuit to an input of the optical Rx circuit. The integrated optical loopback circuit enables in-field testing of the optical transceiver. The integrated optical loopback circuit may include an optical mixer for mixing polarization channels in dual-polarization embodiments of the optical transceiver. A phase tuner may be provided for tuning the optical phase of local oscillator light for mixing I and Q channels of the loopback optical signals in embodiments operating with quadrature modulated signals.

Optical transceiver with integrated optical loopback

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Munich, Germany

Robert Palmer