DBR Fiber Laser Sensor With Polarization Mode Suppression

A distributed Bragg reflector fiber laser sensor based on a commercial high-birefringence Er-doped fiber has been proposed. The spectral overlap of two uniform fiber Bragg gratings has been employed as filtering technique to achieve a sensing head that operates in the single longitudinal mode regime. The high-birefringence Er-doped fiber has been employed to remove a polarization mode, only allowing the oscillation of a single polarization mode. In this way, a single frequency operation with a very stable laser output has been achieved. The proposed fiber laser exhibits a linear response for both strain and temperature variations, keeping the SLM regime and the polarization mode suppression.