Patent attributes
An exemplary optical hybrid includes a 50/50 un-polarized beam splitter, a folding prism, a beam shifter, a spacer and a phase shifter such that from an input S-beam (signal) and an L-beam (reference), four outputs, S+L, S−L, S+jL and S−jL, are produced. The phase difference between the two components of each output beam produced by the S and L beams in the optical hybrid is θ+0, θ+90, θ+180, or θ+270 degrees, where θ is the phase difference of the signal beam with respect to the reference beam. In an alternative embodiment, the phase difference between the two components of each output beam produced by the S and L beams in the optical hybrid is θ+0, θ+X, θ+180, or θ+180+X degrees, where X is an arbitrary number of degrees greater than 0 and smaller than 180.
