Abstract: Systems and techniques relating to automatically-locked homodyne detection are described. A described system includes a first nonlinear element, a filter, and second nonlinear elements. The first nonlinear element can produce, based on an input signal and a first continuous wave (CW) signal, a first output signal that includes the input signal and a phase conjugate copy of the input signal. The filter can produce a filtered signal based on the first output signal and can be programmable to adjust an induced delay between the input signal and the phase conjugate signal. The second nonlinear elements can produce second output signals based on a second CW signal and differently weighted combinations of signal components within the filtered signal. The second output signals can include an in-phase output signal based on an in-phase version of the filtered signal and a quadrature output signal based on a quadrature version of the filtered signal.

Abstract: A device for optical-signal-to-noise (OSNR) monitoring can include: a delay-line interferometer configured to connect with a tunable optical filter; and two or more power detectors to measure outputs of the interferometer; wherein one or more parameters are optimized for different transmission baud rates to improve accuracy. In addition, a method can include: connecting an input of a delay-line interferometer with an output of a tunable optical filter, and an output of the delay-line interferometer with an input of a power detector, to form an optical-signal-to-noise (OSNR) monitoring apparatus; optimizing one or more parameters of the OSNR monitoring apparatus for different transmission baud rates to improve accuracy.

Abstract: Systems and techniques relating to automatically-locked homodyne detection are described. A described system includes a first nonlinear element, a filter, and second nonlinear elements. The first nonlinear element can produce, based on an input signal and a first continuous wave (CW) signal, a first output signal that includes the input signal and a phase conjugate copy of the input signal. The filter can produce a filtered signal based on the first output signal and can be programmable to adjust an induced delay between the input signal and the phase conjugate signal. The second nonlinear elements can produce second output signals based on a second CW signal and differently weighted combinations of signal components within the filtered signal. The second output signals can include an in-phase output signal based on an in-phase version of the filtered signal and a quadrature output signal based on a quadrature version of the filtered signal.

Abstract: The present disclosure includes systems and techniques relating to reconfigurable optical transmitters. In some implementations, an apparatus, systems, or methods can include multiple ports to receive independent optical data signals or independent electrical signals that are converted into independent optical data signals, at least one optical pump laser, and one or more nonlinear optics elements configured and arranged to generate a phase conjugate for each of the independent optical data signals at least by combining the respective independent optical data signal with an output of the optical pump, and generate an output optical signal from the independent optical data signals at least by combining each of the independent optical data signals with its corresponding generated phase conjugate.

Abstract: The present disclosure includes systems and techniques relating to reconfigurable optical transmitters. In some implementations, an apparatus, systems, or methods can include multiple ports to receive independent optical data signals or independent electrical signals that are converted into independent optical data signals, at least one optical pump laser, and one or more nonlinear optics elements configured and arranged to generate a phase conjugate for each of the independent optical data signals at least by combining the respective independent optical data signal with an output of the optical pump, and generate an output optical signal from the independent optical data signals at least by combining each of the independent optical data signals with its corresponding generated phase conjugate.