title: Orthogonal polarization mode coupling for pure twisted polarization maintaining fiber Bragg gratings.
abstract: 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.
authors.affiliation: Research Center of Space Laser Information Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Yang
authors.forename: Zujie
authors.initials: Z
authors.lastname: Fang
authors.forename: Zhengqing
authors.initials: Z
authors.lastname: Pan
authors.forename: Qing
authors.initials: Q
authors.lastname: Ye
authors.forename: Haiwen
authors.initials: H
authors.lastname: Cai
authors.forename: Ronghui
authors.initials: R
authors.lastname: Qu
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D008027:Light; D008962:Models, Theoretical; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation