Patent ID: 7546001

Claim:
A circuit comprising: a substrate; a plurality of forward error correction (FEC) encoders; an optical combiner provided on the substrate, the optical combiner having a plurality of inputs and an output; a plurality of optical sources provided on the substrate, each of the plurality of optical sources providing a corresponding one of a plurality of modulated channel signals, each of the plurality of modulated channel signals having a corresponding one of a plurality of wavelengths, the plurality of wavelengths approximating a wavelength grid, each of the plurality of modulated channel signals carrying information output from a corresponding one of the plurality of FEC encoders; and a service channel photodetector provided on the substrate, wherein each of the plurality of inputs of the optical combiner receives a corresponding one of the plurality of modulated channel signals and a WDM signal is provided at the output of the optical combiner, wherein the optical combiner has an input side where the plurality of inputs are located and an output side where the output is located, a service channel output port being provided on the input side of the optical combiner and the service channel photodetector being coupled to the service channel output port, the optical combiner being configured to receive a service channel signal through the optical combiner output and supply the optical service channel to the service channel photodetector via the service channel output port.