Loss compensated fiber loop ring-down system driven by random distributed multi-pulse laser

The sensing characteristics of loss compensated fiber loop ring-down (FLRD) system driven by random distributed multi-pulse have been analyzed. We used a random distributed multi-pulse laser to drive a fiber loop with loss compensation of erbium-doped fiber amplifier (EDFA) and analyzed the distortion of exponential attenuation curves, sensitivity and baseline stability of the system. The performance is compared with those of loss compensated FLRD system driven by single pulse and chaotic laser. The loss compensated FLRD theoretical model is discussed by the transmission equation of EDFA and finite element analysis. The performance of loss compensated FLRD system driven by random distributed multi-pulse under different injection optical powers is analyzed under the influence of gain saturation effect of EDF and amplified spontaneous emission (ASE). The results show that the random distributed multi-pulse system has higher R-square of exponential attenuation curves and better baseline stability than the single-pulse system. The increase of injection optical power has the least influence on the sensitivity reduction of random distributed multi-pulse system. The random distributed multi-pulse laser has better performance than single-pulse laser and chaotic laser in loss compensated FLRD system.