具有大范围高分辨率线性响应特性的超短无芯光纤溶液折射率传感器*

摘要

The feasibility of applying mode propagation analysis (MPA) method in solving single mode- multimode- single mode (SMS) fiber structure is confirmed by comparing the experimental data with the theoretical results. The method of searching for linear response points on SMS based on MPA was proposed, applied to finding a wide-range high-resolution linear response wavelength theoretically, and confirmed in experiment. By using a 104 µm-in-diameter no-core fiber as short as 4.4 mm, we archived a linear transmission variation of 19.10 dB in the refractive index range of 1.326-1.417, which means a refractive index resolution of 4.76×10−5 according to the resolution of common commercial optical powermeter, and realizes a wide-range high-resolution linear response under the direction of the theory.%　　通过理论与实验对比,证明模式传输分析(MPA)方法求解单模-多模-单模(SMS)结构的可行性.以 MPA 理论为基础,提出了 SMS 结构折射率传感装置线性响应点的寻找方法.利用该方法为实验制作的无芯光纤 SMS 折射率传感器设计了大范围高分辨率线性响应位置,并在实验中获得证实.实验采用短至4.4 mm 的直径104µm 无芯光纤,在折射率1.326-1.417范围上获得了19.10 dB 的功率线性变化,以商用光功率计0.01 dB 分辨率计,折合折射率分辨率4.76×10−5,实现了理论指导下的大范围高分辨率线性响应.