Liquid-Crystal-Cladding Fiber Bragg Gratings with Electrically Controllable Polarization-Dependent Characteristics

摘要

An electrically controllable fiber Bragg grating (FBG) with polarization-dependent characteristics is described. The optic axis of a liquid crystal (LC) can be rearrangeable by means of external electric fields, which results in the change of an effective refractive index of an LC. The reflectivity and Bragg wavelength of an LC-cladding FBG can be controlled according to the refractive index of surrounding region of the fiber which is determined by the refractive index of the LC-cladding. The tuning ranges of the LC-cladding FBG were ～4.6 dB of the reflectivity and ～0.3 nm of Bragg wavelength based cm unpolarized light, respectively, and polarization isolation of 1.5 dB was achieved at 100 V_(p-p) based on polarized light.