Patent ID: 7088878

Claim:
Apparatus for depolarizing light comprising: a beam splitter having an input and two outputs, where a light beam from a first output has a polarization that is orthogonal to a polarization of a light beam from a second output; a beam combiner having a first input coupled to the first output of the beam splitter via a first fiber, a second Input coupled to the second output of the beam splitter via a second fiber, and an output that produces depolarized light, where the first and second fibers are polarization maintaining fibers and the second fiber has a length that provides a predefined delay with respect to the first fiber such that an Interference signal having a delay equal to the predefined delay will be suppressed during a demodulation process; first and second reflectors coupled to the output of the beam combiner to form an interferometer, wherein the reflectors are spaced from one another to provide the interference signal; and a light source, coupled to the beam splitter, having a frequency swept output and the predefined delay is selected to ensure that a cross-correlation between orthogonal polarizations of the source do not appear in extracted signal frequencies within a receiver.