Temperature Fiber Laser Sensor Based on a Hybrid Cavity and a Random Mirror

In the present work, a simple temperature fiber laser sensor configuration is proposed. The temperature fiber laser sensor is based in the combination of a Fabry-Perót hybrid cavity and a random mirror. The Fabry-Perót hybrid cavity is fabricated by splicing a single mode fiber with a small piece of suspended-core fiber. The random mirror is created by multiple Rayleigh scattering events running along the dispersion compensation fiber, as a direct consequence of Raman gain in this fiber. In the proposed configuration, the Fabry-Perót cavity presents simultaneously a double function: laser reflective mirror and temperature sensing cavity. The proposed temperature fiber laser sensor presents maximum output power of ~4 mW in a 15nm wavelength range while providing a temperature sensibility of ~6 pm/^°C, in a 200^°C temperature range.