A temperature sensor with high sensitivity based on the birefringence induced Vernier effect in a symmetrical metal-cladding waveguide (SMCW) structure is theoretically proposed. Due to the guiding layer of SMCW is extended to a sub-millimeter scale, the excited ultra-high order modes is highly sensitive to the variation of thermally modulated refractive index (RI) and the obtained comb-like resonance reflectivity spectrum shifts accordingly as changing the ambient temperature. There is a little difference between the RI of the ordinary light and the extraordinary light of the filled nematic liquid crystal (LC), the resulted slight different free spectral range of two orthogonal polarizations makes their superposition of reflectivity spectrum metamorphose into a period envelope with multiple sub-peaks. The dips in the fitting upper envelope possesses a much enhanced temperature dependent spectrum shift which can be measured by a low-cost integrated-type micro-spectrometer. Such a sensor has no reference resonant cavity and its sensing range can be easily controlled by filling with different kinds of LC.

理论上提出了一种基于双折射感应游标效应的对称金属包覆波导结构中的高灵敏度温度传感器。由于SMCW的引导层扩展到了亚毫米级，激发的超高阶模态对热调制折射率（RI）的变化高度敏感，并且获得的梳状共振反射光谱会随着变化而变化环境温度。普通向列光的RI和填充向列液晶（LC）的非寻常光的RI之间有微小差异，两个正交偏振的自由光谱范围略有不同，从而使它们的反射光谱叠加为具有多个倍数的周期包络亚峰。合适的上封套中的凹陷具有大大增强的与温度相关的光谱偏移，可以通过低成本的集成式微型光谱仪进行测量。这种传感器没有参考谐振腔，可以通过填充不同种类的LC轻松控制其感应范围。