Abstract

We report measurements on a polarization-selective 3 dB fiber directional coupler which demonstrate that the polarization selectivity arises from different mismatches for the propagation constants of the two polarizations. [1, 2] In a polarization-selective directional coupler, light of only one polarization is transferred to a second fiber. In earlier empirical work, couplers exhibiting 9 dB polarization selectivity were made. [2] These couplers are made by polishing techniques [3] which complicates analysis because propagation and coupling parameters vary over the polished region. It is thus important to prove that the mechanism for polarization selectivity is indeed differential mismatch and to see if a simple uniform coupling model is valid.

© 1985 Optical Society of America