Open AccessOrthogonal polarization mode coupling for pure twisted polarization maintaining fiber Bragg gratings
Author(s) -
Fei Yang,
Zujie Fang,
Zhengqing Pan,
Qing Ye,
Haiwen Cai,
Ronghui Qu
Publication year - 2012
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.028839
Subject(s) - optics , polarization (electrochemistry) , fiber bragg grating , orthogonal polarization spectral imaging , materials science , twist , coupled mode theory , mode coupling , polarization maintaining optical fiber , polarization rotator , phosfos , optical fiber , physics , fiber optic sensor , refractive index , laser , birefringence , geometry , chemistry , mathematics
Spectral characteristics of orthogonal polarization mode coupling for pure twisted polarization maintaining fiber Bragg gratings (PM-FBG) are proposed and analyzed experimentally and theoretically. Different from the polarization mode coupling in PM-FBG due to side pressure, a resonant peak at the middle of two orthogonal polarization modes is found when the PM-FBG is twisted purely which is attributed to the cross coupling of polarization modes. Its intensity increases with the twisting rate. A new coupled mode equation is built to describe the pure twist polarization mode coupling, in which both the normal strain induced by strain-applied parts and the tangential strain induced by twisting are taken into consideration and expressed in a unified coordinate. The novel phenomenon and its explanation are believed to be helpful for PM-FBG applications in fiber sensor and laser technologies.