Compact polarimetric heterodyning DBR fiber laser sensor with high temperature resistance

We report on a short-cavity polarization beat-frequency distributed Bragg reflector (DBR) fiber laser that can operate in an unprecedentedly wide range of temperatures from -200 to 500°C. The beat-frequency signal inherited by the intrinsic fiber birefringence enables implementation of the laser as an eligible temperature or hydrostatic pressure sensor. Furthermore, type-IIa Bragg reflectors allow the annealing of high temperature on the laser cavity to suppress the phase noise of the lasing signal effectively. This research will guide future attempts to achieve high-precision sensing and high-performance signal generation using polarized beat-frequency DBR fiber lasers in harsh environments.