High sensitivity temperature sensor based on photonic crystal resonant cavity

Abstract

In this paper we investigate a new design of high sensitivity photonic crystal temperature sensor (PCTS). A square lattice of silicon (Si) rods immersed in air matrix is used as a basic structure. The designed sensor consists of two inline quasi-waveguides which are coupled to a resonant cavity (RC). The sensing principle is based on Si refractive index change caused by the variation of the temperatures over a range from 0 to 80°C. This variation leads to an important shift in the resonance wavelength. The performance of the suggested temperature sensor has been analyzed and studied using finite-difference time domain (FDTD) method. The results show that our designed structure offers a high sensibility of 93, 61 pm/°C and quality factor of 2506.5. Its structure is very compact with total size 115.422 µm2, which is suitable for nanotechnology based sensing applications.