Analysis of Temperature-Dependent Optical Properties in 1D Ternary Superconducting Photonic Crystal with Mirror Symmetry

The temperature dependence of the defect mode in a 1D ternary superconducting photonic crystal (PC) with mirror symmetry was theoretically investigated by simultaneously considering thermal expansion effect and thermal-optical effect. Three different materials H (high-refractive index dielectric), L (low-refractive index dielectric), and S (superconducting material) are used to construct the ternary superconducting PC structure. For comparison, six structures are discussed. It is found that the structure (HLS) (N) (SLH) (N) has the highest temperature sensitivity. Here, N is the number of periods. The average change in the central wavelength of the defect mode is 31.18 nm/K as the thickness of superconducting layer is 50 nm. Thus, based on the structure (HLS) (N) (SLH) (N) , a low temperature sensor with higher sensitivity can be designed to realize the low temperature sensor.