基于可调谐激光器稀疏采样的高灵敏度光纤盐度传感器

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关键词：可调谐激光器；稀疏采样；游标效应；法布里-珀罗；光纤盐度传感器中图分类号：0436 文献标识码：Adoi：10.37188/OPE.20253322.3449 CSTR：32169.14.OPE.20253322.3449

Abstract： Aiming at the problem of limited sensitivity of optical fiber salinity sensors，this paper proposed a high-sensitivity fiber optic Fabry-Perot （Fabry-Perot Interferometer，FPI） salinity sensor based on sparse sampling of a tunable laser. By controlling the sampling interval of the tunable laser to be close to the free spectral range（Free Spectral Range，FSR）of the FPI interferometric cavity，a vernier-like effect was formed in the spectrum. Under sparse sampling conditions，the interference signal generated adjustable envelope drift in the spectrum，which significantly amplified the refractive index perturbation caused by small salinity changes，thereby enabling high-sensitivity detection of salinity parameters.Experimental results demonstrate that the sensing system achieves a salinity sensitivity of up to 1.525nm/% within the range of 20‰ salinity，which is approximately 9.24 times higher than that of a single FPI interferometer structure.Compared with the traditional vernier efect method based on a dual-cavity interferomer ter structure，the present sensor does not require any modification to the existing structure and can flexibly control system sensitivity and enhance detection accuracy simply by adjusting the sampling interval of the tunable laser source.The method is simple to implement，highly compatible，and has broad application prospects in the fields of high-performance fiber optic sensing and marine environment monitoring.

Key words： tunable laser; sparse sampling; vernier effect;Fabry-Perot; fiber optic salinity sensor

1引言

在海洋环境监测中，海水盐度是表征海水物理与化学性质的关键指标之一，对海洋中化学反应、生物过程分析、环境监测以及生态系统健康评估等方面均发挥着重要作用[1-3]。（剩余13839字）