Zhao Fang, Lin Weihao, Hu Jie, Liu Shuaiqi, Yu Feihong, Chen Xingwei, Wang Guoqing, Shum Perry Ping, Shao Liyang
Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Macau 999078, China.
Sensors (Basel). 2022 Nov 5;22(21):8533. doi: 10.3390/s22218533.
This paper presented a new kind of salinity and temperature dual-parameter sensor based on a fiber ring laser (FRL) with tapered side-hole fiber (SHF) embedded in a Sagnac interferometer. The sensing structure is majorly composed of tapered SHF located in the middle of SHF inside the Sagnac interferometer loop structure. The influences of the SHF's diameters of different tapered in the Sagnac interferometer loop on the FRL sensing system are studied. The presence of air holes in the SHF makes the cladding mode easier to excite, and the interaction between the cladding mode with its surroundings is enhanced, thus having higher salinity sensitivity. Besides, the unique advantages of high resolution, narrower linewidth, and high signal-to-noise ratio (SNR) of fiber laser make the measurement results more accurate. In this experiment, the SHF with different taper diameters was made, and it was found that reducing the diameter of the taper waist diameter could further improve the salinity sensitivity. When the waist diameter was 9.70 μm, the maximum salinity sensitivity of 0.2867 nm/‱ was achieved. Temperature sensing experiments were also carried out. The maximum temperature sensitivity of the FRL sensing system was -0.3041 nm/°C at the temperature range from 20 to 30 °C. The sensor has the characteristics of easy manufacture, good selectivity, and high sensitivity, proving the feasibility of simultaneous measurement of seawater salinity and temperature.
本文提出了一种基于光纤环形激光器（FRL）的新型盐度和温度双参数传感器，该光纤环形激光器中嵌入了位于萨尼亚克干涉仪中的带锥形边孔光纤（SHF）。传感结构主要由位于萨尼亚克干涉仪环路结构内SHF中间的锥形SHF组成。研究了萨尼亚克干涉仪环路中不同锥形的SHF直径对FRL传感系统的影响。SHF中气孔的存在使得包层模更容易激发，并且增强了包层模与其周围环境之间的相互作用，从而具有更高的盐度灵敏度。此外，光纤激光器具有高分辨率、窄线宽和高信噪比（SNR）的独特优势，使得测量结果更加准确。在本实验中，制作了不同锥径的SHF，发现减小锥腰直径可以进一步提高盐度灵敏度。当腰径为9.70μm时，实现了0.2867nm/‱的最大盐度灵敏度。还进行了温度传感实验。在20至30°C的温度范围内，FRL传感系统的最大温度灵敏度为-0.3041nm/°C。该传感器具有易于制造、选择性好和灵敏度高的特点，证明了同时测量海水盐度和温度的可行性。
