A novel temperature sensor based on rare earth fiber peanut (REFP) shape structure in fiber ring laser (FRL) is proposed and demonstrated. A single-mode rare earth doped fiber is used to fabricate a peanut structure to produce Mach–Zehnder interferometer (MZI). Benefited from the strong thermo-optic effect of rare earth ions in fiber, high sensitivity measurement of temperature is exploited to realize. More importantly, there is no need for additional filters compared to traditional fiber laser sensors. The sensitivity of refractive index (RI) was measured to further verify the sensing performance of MZI. The experimental results show that compared with the external sensing unit, the Er-doped fiber peanut (EDFP) structure has higher thermo optic effect coefficient and superior temperature sensitivity. The temperature and RI sensitivity of the EDFP is 0.158 nm/°C and −19.55 nm/RIU, respectively. The optical fiber MZI sensor based on the EDFP has the advantages of high sensitivity, good repeatability, simple fabrication, and compact structure. It has good application prospects in biomedicine, aerospace, and marine development.

中文翻译：

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光纤环形激光器中基于Er掺杂的光纤花生结构的光纤马赫曾德尔干涉仪传感器

提出并论证了一种基于光纤环形激光器（FRL）中的稀土纤维花生（REFP）形状结构的新型温度传感器。单模稀土掺杂光纤用于制造花生结构，以生产马赫曾德尔干涉仪（MZI）。由于稀土离子在光纤中具有强大的热光效应，因此可以实现对温度的高灵敏度测量。更重要的是，与传统的光纤激光传感器相比，不需要额外的滤波器。测量了折射率（RI）的灵敏度，以进一步验证MZI的传感性能。实验结果表明，与外部传感单元相比，掺Er花生纤维（EDFP）结构具有更高的热光学效应系数和优异的温度敏感性。EDFP的温度和RI灵敏度分别为0.158 nm /°C和-19.55 nm / RIU。基于EDFP的光纤MZI传感器具有灵敏度高，重复性好，制作简单，结构紧凑的优点。它在生物医学，航空航天和海洋开发中具有良好的应用前景。