基于硅透镜与光子晶体的逆古斯汉欣位移监测系统及其温度特性研究

基于硅介质柱型光子晶体，采用时域有限差分方法（FDTD），探究高斯光束在光子晶体界面的逆古斯汉欣（GH）位移。通过在光子晶体下表面添加硅透镜，研究高斯光束的入射角度、硅透镜的曲率半径以及温度对光子晶体逆GH位移的影响。研究结果表明，发生最大逆GH位移的角度大于几何理想全反射角。添加焦点位于光子晶体表面中心的硅透镜可以使逆GH位移显著增强，且当硅透镜的曲率半径为170时，逆GH位移增大为不加透镜时的1.7倍。研究不同入射角度下温度对光子晶体的逆GH位移的影响发现，当高斯光束的入射角为26o时，逆GH位移随着温度的变化最大且线性度较好，便于温度监测。

Study on the inverse Goos-Hanchen shift monitoring system based on silicon lens and photonic crystal and its temperature characteristics

Based on the silicon dielectric cylindrical photonic crystal, the finite-difference time-domain (FDTD) method is used to investigate the inverse Goos-Hanchen (GH) shift of Gaussian beam at the photonic crystal interface. By adding a silicon lens on the lower surface of the photonic crystal, the influence of the incident angle of Gaussian beam, the curvature radius of the silicon lens and the temperature on the inverse GH shift of the photonic crystal is studied.The results show that the maximum inverse GH shift angle is larger than the geometric ideal total reflection angle. The addition of a silicon lens with the focus in the center of the photonic crystal surface can significantly enhance the inverse GH shift. When the curvature radius of the silicon lens is 170, the inverse GH shift increases by 1.7 times as much as that without the lens. The influence of temperature on the inverse GH shift of photonic crystal at different incident angles is studied. It is found that when the incident angle of Gaussian beam is 26 degrees, the inverse GH shift has a wide range of variation with temperature, and the linearity of variation curve is better, which is convenient for temperature monitoring.