Polarization controller based on a fiber–recirculating delay line

Abstract

A fiber-optic polarization control device constructed from a recirculating delay line is introduced and analyzed. This controller is found to be without a bulk optic counterpart and is notably different in design and operation from existing fiber polarization controllers. Full control is achieved by varying two birefringence terms and a phase delay term. The device is shown to be capable of handling arbitrary polarization-state transformations and control. The design technique for this system is also fundamentally different from that of previous polarization controllers.