Optical Sensor by Utilizing the Injection Locking in the Er-doped Fiber Loop Laser

We added a slave laser on the base of the ring distributed feedback fiber laser to construct the source of fiber-optic sensor. The loop mainly consisted of a laser diode, an Er-doped fiber amplifier, an isolator, and a photodetector. Furthermore we chose the fiber bragg grating as sensing element which was sensitive to temperature. The function of locked slave laser is a narrow tunable optical filter. It purified the output spectrum, lowered the phase noise, as well as affording some power amplification. Measured results of the system waveform under different temperatures indicate that the system can indicate the variation of temperature sensibly and the performance of the temperature sensor was optimized. The system can be available to fire prediction in the future.