Jones calculus analysis of single-mode fiber Sagnac reflector.

It is postulated that stray birefringence degrades the performance of the single-mode fiber Sagnac reflector. An expression for the birefringence dependence of reflector performance is derived using the Jones calculus and is used as the basis for a theoretical model of the spectral response of a real Sagnac reflector. The experimental behavior of the reflector with (1) different levels of stress applied to the fiber loop and (2) different lengths of highly birefringent fiber spliced into the loop are compared with the model. This comparison confirms the initial postulate.