Abstract

To date numerous methods for fabricating polarization-preserving couplers have been reported. In one approach, a specially designed polarization-preserving coupler-fiber, having an external feature which facilitates birefringent axis alignment, was used to fabricate couplers with a polarization extinction ratio approaching 20 dB.^1,2 With the more traditional approach, which uses standard low-loss polarization preserving fiber, the results have not been very repeatable, generally achieving useful yields of <10%, the insertion loss has been high, usually >2 dB, and the polarization extinction ratio was In the 10-15-dB range.^3,4

© 1986 Optical Society of America