Song Jiao, Sun Simei, Jiang Chao, Chen Hailin, Wang Saiyu
College of Physics and Electronic Science, Hubei Normal University, Huangshi, Hubei 435002, China.
Rev Sci Instrum. 2021 Dec 1;92(12):125003. doi: 10.1063/5.0068108.
In this paper, a Mach-Zehnder interferometer temperature sensor with a single-mode fiber-thin-core fiber-single-mode fiber cascaded is designed. When the light is transmitted from the single-mode fiber to the thin-core fiber, different modes will be excited because of the mode-field mismatch. Optical power from the input fiber can be partly coupled to the cladding modes of the thin-core fiber, and the cladding modes of the thin-core fiber then re-coupled to the lead-out fiber, which constitutes the Mach-Zehnder interferometer in the output single-mode fiber. To improve the temperature sensitivity of the sensor, we coated the thermal-sensitive material (such as polymethoxane or ultraviolet glue) on the surface of the thin-core fiber. The experimental results show that the temperature sensitivity of the sensor coated with a polydimethylsiloxane film was increased from 32.0 to 90.0 pm/°C, about three times, compared to the uncoated thin-core fiber sensor. When the surface of the thin-core fiber is coated with an ultraviolet glue film, the temperature sensitivity of the sensor was increased from 32.0 to 166.8 pm/°C, about six times. The designed sensor, with compact structure, simple production, strong robustness, and high sensitivity, has a wide application prospect in industrial production and national defense technology.
本文设计了一种由单模光纤-细芯光纤-单模光纤级联的马赫-曾德尔干涉仪温度传感器。当光从单模光纤传输到细芯光纤时，由于模场失配会激发不同的模式。输入光纤的光功率可以部分耦合到细芯光纤的包层模式，然后细芯光纤的包层模式再耦合到输出光纤，这就在输出单模光纤中构成了马赫-曾德尔干涉仪。为了提高传感器的温度灵敏度，我们在细芯光纤表面涂覆了热敏材料（如聚甲氧基烷或紫外胶）。实验结果表明，与未涂覆的细芯光纤传感器相比，涂覆聚二甲基硅氧烷薄膜的传感器温度灵敏度从32.0提高到90.0 pm/°C，提高了约三倍。当细芯光纤表面涂覆紫外胶薄膜时，传感器的温度灵敏度从32.0提高到166.8 pm/°C，提高了约六倍。所设计的传感器结构紧凑、制作简单、鲁棒性强、灵敏度高，在工业生产和国防技术中具有广阔的应用前景。
