Gao Song, Baker Chams, Chen Liang, Bao Xiaoyi
Opt Lett. 2018 Apr 1;43(7):1523-1526. doi: 10.1364/OL.43.001523.
A temperature-insensitive strain sensor is proposed and demonstrated based on a dual-core AsSe-polymethyl methacrylate (PMMA) taper. Longitudinal and transverse forces on the AsSe cores are induced by thermal expansion/contraction of the PMMA cladding due to an order of magnitude difference between the thermal expansion coefficients of AsSe and PMMA. At an optimal PMMA layer thickness, the wavelength shift caused by the thermally induced forces on the refractive index of the dual-core fiber cores counterbalances that caused by the thermally induced fiber length variation leading to temperature-insensitive transmission. Temperature-insensitive strain measurement over a temperature range from 30°C to 40°C is demonstrated in a dual-core AsSe-PMMA fiber with an AsSe core diameter of 0.61 μm and a PMMA cladding diameter of 34.4 μm. Thermally induced forces in hybrid fibers open the path towards the realization of novel sensors and devices that are immune to temperature fluctuations.
基于双芯砷硒-聚甲基丙烯酸甲酯（PMMA）锥形结构，提出并演示了一种对温度不敏感的应变传感器。由于砷硒和聚甲基丙烯酸甲酯的热膨胀系数存在一个数量级的差异，聚甲基丙烯酸甲酯包层的热膨胀/收缩会在砷硒芯上产生纵向和横向力。在最佳的聚甲基丙烯酸甲酯层厚度下，由热致力引起的双芯光纤芯折射率变化所导致的波长偏移，与热致光纤长度变化所导致的波长偏移相互抵消，从而实现对温度不敏感的传输。在芯径为0.61μm的砷硒芯和包层直径为34.4μm的双芯砷硒-聚甲基丙烯酸甲酯光纤中，演示了在30°C至40°C温度范围内对温度不敏感的应变测量。混合光纤中的热致力为实现对温度波动免疫的新型传感器和器件开辟了道路。
