Elliptical birefringence model for highly efficient study of SOP and DOP in complicated birefringent fiber

Abstract

Optical chirality has recently let to many novel prospects and applications and this phenomenon also exists in twisting linear birefringent fiber. However, it has not been investigated when the birefringence is non-uniform, namely, both the spinning rate and linear birefringence vary along the fiber axis. Additionally, this non-uniformity brings dissatisfaction in terms of computational efficiency when using traditional methodologies, such as the coupled mode theory and the cascaded linear phase delayer matrix model. In order to study this kind of complicated birefringent fiber (CBF), this work introduces an innovative solution to this issue: the elliptical phase delayer model, specifically designed to analyze situations where the optical fiber experiences arbitrary spinning. The derivation of this model employs the Jones matrix, and its validity and computational efficiency are verified through numerical calculations. Furthermore, this work explores the State of Polarization (SOP) of CBF using the proposed model. It also investigates the Degree of Polarization (DOP) of the output light wave, which is indicative of the depolarization effect due to spinning. This study presents an elliptical phase delayer model that offers an efficient means of calculating the SOP and DOP of CBF, and is also applicable to other spun optical structures.