Xie Jianglei, Xu Ben, Li Yi, Kang Juan, Shen Changyu, Wang Jianfeng, Jin Yongxing, Liu Honglin, Ni Kai, Dong Xinyong, Zhao Chunliu, Jin Shangzhong
Appl Opt. 2014 Jun 20;53(18):4085-8. doi: 10.1364/AO.53.004085.
A low-cost yet high-sensitivity temperature fiber sensor is proposed and demonstrated in this paper. A single-mode fiber with coating is simply bent in a droplet-like circle with a radius of several millimeters. The strong bending induces mode interferences between the silica core mode and the excited modes propagating in the polymer coating. Many resonant dips were observed in the transmission spectra and are found to shift to a shorter wavelength with the increase of environmental temperature. Our linear fitting result of the experimental data shows that the proposed sensor presents high temperature sensitivity up to -3.102 nm/°C, which is even comparable with sensors based on selective liquid-filled photonic crystal fibers. Such high temperature sensitivity results from the large thermo-optical coefficient difference between the silica core and the polymer coating. The influence of a circle radius to the sensitivities is also discussed.
本文提出并演示了一种低成本但高灵敏度的温度光纤传感器。一根带涂层的单模光纤被简单地弯曲成半径为几毫米的液滴状圆圈。强烈的弯曲会在二氧化硅纤芯模式与在聚合物涂层中传播的激发模式之间引发模式干涉。在传输光谱中观察到许多谐振凹陷，并且发现随着环境温度的升高，这些凹陷会向较短波长移动。我们对实验数据的线性拟合结果表明，所提出的传感器呈现出高达 -3.102 nm/°C 的高温灵敏度，这甚至与基于选择性填充液体的光子晶体光纤的传感器相当。如此高的温度灵敏度源于二氧化硅纤芯与聚合物涂层之间较大的热光系数差异。还讨论了圆圈半径对灵敏度的影响。
