High-Resolution Static Strain Sensor Based on Random Fiber Laser and Beat Frequency Interrogation

We proposed a high-resolution static strain sensor using random fiber lasers (RFLs) and the sweep-beat frequency interrogation technique. An RFL with 3-dB linewidth of 548 Hz and frequency jitter of ~±70 kHz is established by random distributed gratings and a high-precision π-phase shifted fiber Bragg grating (π-FBG) ring mirror. Two RFLs act as probes and are interrogated by frequency-swept laser...