Provided is an apparatus and method for use thereof. The apparatus, in one embodiment, includes a 1.times.2 coupler in communication with a waveguide. The 1.times.2 coupler, in this embodiment, is configured to separate an input finite bandwidth optical signal provided from the optical waveguide into two similar optical signals. Input ends of first and second waveguide arms, in one embodiment, are in communication with the 1.times.2 coupler and configured to receive ones of the input optical signals. An inherent birefringence of each of the first and second waveguide arms may be substantially similar. Moreover, the first and second waveguide arms have different physical path lengths that differ by an amount (.DELTA.L). Additionally, a 2.times.2 coupler may be in optical communication with an output end of the first and second waveguide arms and configured to provide an output TE polarization and an output TM polarization.