Polarimetric DBR fiber laser sensor for strain-temperature discrimination

A polarimetric Distributed Bragg Reflector (DBR) laser sensor in a low birefringent Er-doped fiber has been proposed. The spectral overlap of two uniform fiber Bragg gratings (FBG) has been employed as filtering technique to achieve a Single Longitudinal Mode (SLM) regime. By measuring the RF beat frequency between the two orthogonal polarized lasing modes and the absolute wavelength of one mode, both strain and temperature has been determined simultaneously.