Fig. 1. Schematic of PT symmetry structure temperature sensor

Fig. 2. Transmittance spectrum of structure when N=5

Fig. 3. Transmittance spectra of structure when N=4, 5, 6, 7

Fig. 4. Transmittance spectra of structure when refractive indexes of layer B, D are (a) 2.21095, (b) 2.211, (c) 2.21105

Fig. 5. (a) Temperature dependence of transmittance when incidence wavelength equals 1550 nm; (b) original data and fitting curve

Fig. 6. Temperature dependence of transmittance with different values of α

Fig. 7. Tendency of detecting range ΔT and sensitivity of sensor with α