Periodic microbending-induced core-to-cladding mode coupling in polarization-maintaining fibers.

Abstract

We investigate codirectional mode coupling induced by periodic microbending in polarization-maintaining (PM) fibers by using both an acoustic flexural wave and a pair of corrugated fixtures. The measured filtering spectra are found to be strongly polarization dependent. In addition, the coupling strength depends on the angle between the birefringence axes and the bending direction. These characteristics can be utilized for a variety of applications, such as fiber polarizers, polarization-dependent-loss compensators, and on-line alignment of birefringence axes for the manufacture of PM fiber couplers.