Photonic wavelength division multiplexing (WDM) receiver with polarization diversity and/or low reflectance

A photonic wavelength division multiplexing with polarization diversity method, comprising:

• receiving and splitting a multi-wavelength light beam into a first polarized multi-wavelength light beam and a second polarized multi-wavelength light beam, the received multi-wavelength light beam having data encoded in a plurality of wavelengths for a plurality of channels;
• guiding the first and second polarized multi-wavelength light beams over equal path lengths to a first micro-ring resonator of a plurality of micro-ring resonators and a second micro-ring resonator of the plurality of micro-ring resonators, wherein the first and second polarized multi-wavelength light beams arrive at the first micro-ring resonator at a first time, wherein the first and second polarized multi-wavelength light beams arrive at the second micro-ring resonator at a second time, and wherein the second time is after the first time;
• and
• respectively filtering, at the first and second micro-ring resonators, both the first and second polarized multi-wavelength light beams for corresponding ones of the plurality of wavelengths to receive the data encoded therein for the channels.

A photonic wavelength division multiplexing (WDM) receiver with reduced reflectance, comprising:

• a splitter to receive a multi-wavelength light beam from a transmitter, and split the received multi-wavelength light beam into a first multi-wavelength light beam and a second multi-wavelength light beam, the received multi-wavelength light beam having data encoded in a plurality of wavelengths for a plurality of channels;
• a plurality of photodetectors to respectively demultiplex the plurality of wavelengths;
• a looped waveguide coupled with the splitter and the plurality of photodetectors to optically couple the first and second multi-wavelength light beams from the splitter to the plurality of photodetectors;
• first and second variable optical attenuators (VOAs), respectively disposed at a first location of the looped waveguide between the splitter and a first of the photodetectors, and at a second location of the looped waveguide between the splitter and a second of the photodetectors to suppress reflection of the first and second multi-wavelength light beams back to the transmitter;
• and
• a feedback structure having a plurality of photodiodes to respectively measure photocurrents of the first and second multi-wavelength light beams.

A photonic wavelength division multiplexing with reduced reflectance method, comprising:

• receiving from a transmitter a multi-wavelength light beam, and splitting the multi-wavelength light beam into a first multi-wavelength light beam and a second multi-wavelength light beam, the received multi-wavelength light beam having data encoded in a plurality of wavelengths for a plurality of channels;
• loop guiding the first and second multi-wavelength light beams to a plurality of detection locations;
• respectively demultiplexing, at the detection locations, the first and second multi-wavelength light beams, in parallel, for corresponding ones of the plurality of wavelengths, to receive the data encoded therein for the channels;
• and
• configuring one or more variable optical attenuators (VOAs) to suppress reflection of the first and second multi-wavelength light beams back to the transmitter, wherein configuring includes measuring photocurrents of the first and second multi-wavelength light beams, and configuring one or more of the one or more VOAs in view of the measured photocurrents.