Dual polarization unit for coherent transceiver or receiver

A coherent transceiver or receiver comprising:

• a data signal dual polarization unit configured to receive a data signal and provide a transverse electric (TE) data signal having TE polarization and a transverse magnetic (TM) data signal having TM polarization, wherein the time-dependence and amplitude of the TE data signal is the same as the TM data signal;
• a local oscillator signal polarization unit configured to receive a local oscillator signal and provide a TE local oscillator signal having TE polarization and a TM local oscillator signal having TM polarization, wherein the time-dependence and amplitude of the TE local oscillator signal is the same as the TM local oscillator signal;
• a TE hybrid coupler configured to receive the TE data signal and the TE local oscillator signal and provide one or more TE coupled signals to one or more photodetectors of an array of photodetectors;
• and
• a TM hybrid coupler configured to receive the TM data signal and the TM local oscillator signal and provide one or more TM coupled signals to one or more photodetectors of the array of photodetectors,
• wherein the array of photodetectors comprises a plurality of photodetectors, each photodetector of the plurality of photodetectors configured to receive one of the one or more TE coupled signals or TM coupled signals and provide an electric signal based on the received one of the one or more TE coupled signals or TM coupled signals, and
• wherein the data signal dual polarization unit comprises:
• a data polarization splitter configured to split an incoming signal into a data TE mode signal and a data TM mode signal;
• a data TE splitter configured to split the data TE mode signal into a first data TE signal and a second data TE signal;
• a data TM splitter configured to split the data TM mode signal into a first data TM signal and a second data TM signal;
• a first data TE signal polarization rotation component configured to receive the first data TE signal and provide a third data TM signal having the same amplitude and time dependence as the first data TE signal;
• a first data TM signal polarization rotation component configured to receive the first data TM signal and provide a third data TE signal having the same amplitude and time dependence as the first data TM signal;
• a data TE coupler configured to couple the second data TE signal and the third data TE signal to generate an output data TE signal;
• and
• a data TM coupler configured to couple the second data TM signal and the third data TM signal to generate an output data TM signal.