Reconfigurable Phase-Shifted Fiber Bragg Grating Using Localized Micro-Strain

A simple and precise method for tuning of localized phase shift in fiber Bragg grating (FBG) using mechanical micro-strain is proposed and experimentally verified. Positive and negative continuous phase shifts tuning between 0 and +π/-π in a uniform FBG is experimentally demonstrated using confined micro-strain in a beam bending configuration. The magnitudes of the temporary phase shifts can be linearly controlled by changing the load displacement, with set-and-forget capability.