Abstract: 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.

Abstract: 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.

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

Abstract: 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.

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

Abstract: 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.

Abstract: 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.

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

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

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

Abstract: 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.

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

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

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

Abstract: A method for operating an optical network element is provided, wherein based on a quality parameter a subsequent set of parameters is selected to operate the optical network element. Also, an according optical network element and a communication system comprising at least one such optical network element are suggested.

Abstract: A method for operating an optical network element is provided, wherein based on a quality parameter a subsequent set of parameters is selected to operate the optical network element. Also, an according optical network element and a communication system comprising at least one such optical network element are suggested.

Abstract: A receiver contains a phase demodulator and an electronic dispersion compensator that is electrically connected to the phase demodulator. The phase demodulator contains a delay that is equal to or less than 1 bit. Ideally the delay is an adjustable delay. Further, a method for operating the receiver described above is discussed.