Patent ID: 8750703

Claim:
An apparatus comprising: an optical transmitter; a coarse tuner coupled to the optical transmitter and having a first tuning range; a fine tuner coupled to the optical transmitter and having a second tuning range smaller than and within the first tuning range; a wavelength division demultiplexer coupled to the optical transmitter and to a plurality of optical fibers; a detector coupled to the optical transmitter and the wavelength division demultiplexer; an optical circulator positioned between the optical transmitter and the wavelength division demultiplexer and between the wavelength division demultiplexer and the detector; a splitter positioned between the optical transmitter and the optical circulator and between the optical transmitter and the detector; and a polarizing beam splitter positioned between the optical circulator and the detector, wherein the detector is coupled to a first output from the polarizing beam splitter.