Patent ID: 8538277

Claim:
An apparatus, comprising: a local oscillator including a laser, the laser supplying light; an optical splitter configured to receive the light, the optical splitter having a first output configured to supply a first portion of the light and a second output configured to receive a second portion of the light; optical hybrid circuitry configured to receive the first and second portions of the light from the laser of the local oscillator; optical demultiplexing circuitry configured to receive a wavelength division multiplexed (WDM) signal including a plurality of optical signals, the optical demultiplexing circuitry further including a plurality of waveguides, each of which supplying a corresponding one of the plurality of optical signals, each of the plurality of optical signals having a corresponding one of a plurality of wavelengths, the optical hybrid circuitry receiving one of the plurality of optical signals from the optical demultiplexing circuitry; and a plurality of photodiodes configured to receive optical outputs from the optical hybrid circuitry, wherein the plurality of optical signals is a first plurality of optical signals, the optical demultiplexing circuitry is further configured to receive a second plurality of optical signals, each of the second plurality of optical signals having a corresponding one of the plurality of wavelengths, said one of the plurality of optical signals being one of the first plurality of optical signals and having one of the plurality of wavelengths, one of the second plurality of optical signals being supplies to the optical hybrid circuitry, said one of the second plurality of optical signals having said one of the plurality of wavelengths.