Quasi-distributed hybrid dynamic-static signal interrogation system using 100-kHz linewidth laser

A quasi-distributed fiber sensing system based on a 100 kHz linewidth laser is demonstrated, employing a double-sideband optical frequency domain reflectometry (DSB-OFDR) architecture for simultaneous dynamic and static signal measurement. The sensing distance is no longer constrained by the laser’s coherence length, and the measurement range is independent of the sweep range. The experimental results validate that the system achieves performance comparable to that of a narrow-linewidth laser, with the capability to detect dynamic and static signals with wide range and high resolution.