High resolution fiber Bragg grating interrogation using a random distributed feedback fiber laser

Abstract

In this study, a new sensing application for random distributed feedback fiber lasers is presented. Temperature measurements of a phase-shifted fiber Bragg grating with a resolution higher than 0.01 ºC have been attained. The resolution limitation of classical fiber lasers has been overcome due to the absence of longitudinal modes and high frequency stability of random fiber lasers. The frequency shift of the grating has been measured as 1.195 ºC/GHz and it is detected in the electrical domain by beating an external laser source with the random emission line generated.