Patent ID: 6975790

Claim:
An apparatus for forming a WDM signal having orthogonally polarized optical channels without using polarization maintaining fiber outside the transmitter, comprising: a first plurality of optical channels formed using non-polarization-maintaining components, where an optical signal of each channel has a first state of polarization (SOP) determined by a polarization controller of the channel; a second plurality of optical channels formed using non-polarization-maintaining components, where an optical signal of each channel has a second state of polarization (SOP) determined by a polarization controller of the channel; an N×1 wavelength multiplexer for combining the first and second plurality of optical channels, the multiplexer having an output adapted for outputting the WDM signal; a broadband wavelength insensitive splitter for tapping a portion of the WDM signal power; a polarization splitter coupled to the first output of the broadband splitter, the polarization splitter having a first output for the optical signals having the second SOP and a second output for the optical signals having the first SOP; a first wavelength demultiplexer of the first plurality of the optical channels, the demultiplexer coupled to the first output of the polarization splitter; a second wavelength demultiplexer of the second plurality of the optical channels, the demultiplexer coupled to the second output of the polarization splitter; and a plurality of sensors of optical power of a respective optical channel, each sensor coupled to a control input of the polarization controller of the respective optical channel, wherein the first SOP is orthogonal to the second SOP.