Reflective structure for phase-shifted fiber Bragg grating.

A novel, to the best of our kowledge, reflective phase-shifted fiber Bragg grating (R-PS-FBG) structure composed of a conventional fiber Bragg grating (FBG) and a micromirror with an air gap between them is proposed. The R-PS-FBG may be regarded as consisting of a Fabry-Perot interferometer and a phase-shifted fiber Bragg grating (PS-FBG), and its reflection and transmission spectra are investigated numerically and experimentally for different mirror reflectances and gap widths. The R-PS-FBG can be implemented easily and could be used in optical spectrum filtering, wavelength tuning, and multiparameter sensing with better sensitivity and resolution.