Analysis of a photonic crystal temperature sensor based on Z-shaped ring resonator

A 2D photonic crystal (PC) sensor based on optical filter has been designed using a PC ring resonator (PCRR). The sensor used a 2D-PCRR triangular lattice with circular silicon rods placed in air background. We employed a ring resonator with Z-shaped core in the investigated structure, which is designed as temperature sensor and investigated theoretically along with high quality factor, transmission and sensitivity parameters. For sensing analysis, the 2D finite-difference time-domain method and the plane-wave expansion approach have been applied. A temperature variation from 0 to 20 °C causes a defect mode shifting and the channel filter wavelength shift was used as sensing mechanism. Using the number of the functionalized rods N = 36 at the temperature of 5 °C, the quality factor, the temperature sensitivity, the refractive index sensitivity and the detection limit of the studied structure were found to be 57,104, 96 pm/°C, 400 nm/RIU and 6.16 × 10–6 RIU, respectively.