Design and simulation of a highly sensitive photonic crystal temperature sensor based on a cavity filled with the distilled water

In this paper design and two dimensional (2D) simulation of a photonic crystal highly sensitive temperature sensor is presented. The 2D simulations are based on finite-difference time-domain (FDTD) method and are done using Rsoft software. The device is constructed using a cavity filled with the distilled water located in the center of the photonic crystal waveguide. The operation of the proposed sensor is investigated considering the thermal variations of the refractive index of the background material (Si) and the cavity’s filled material (the distilled water) and also the thermal expansion of the structure. It has been shown that the radii of the cavity and its surrounding holes have an important role in the performance of the device. It has been shown that the relationship between the temperature variation and the shift in the resonant wavelength of the cavity is linear. Based on the simulation results, the sensitivity, the quality factor and the transmission of the proposed sensor are 149.79 pm/c, 6105 and 0.6, respectively.