Novel Design for the Temperature Sensing Using Annular Photonic Crystals

In this research, a high-performance temperature sensor of a one-dimensional defective annular photonic crystal is proposed. The structure design of our proposed defective annular photonic crystal is: [(Si/SiO2) N/2 TiO2 (Si/SiO2) N/2] with TiO2 as a defect layer. The transmission spectrum of the defective annular photonic crystal is calculated by using the well-modified transfer matrix method in cylindrical coordinates. Thermal characteristics of the defect mode that emerged in the transmission spectrum are studied in the visible region. Dependence of the defect mode frequency on the defect layer thickness is also discussed. As temperature increases, the defect mode is shifted to new positions due to thermal expansion and thermo–optical effects. Numerical results show that the core radius has an important effect on the transmission intensity of the defect mode. Moreover, our proposed temperature sensor showed a sensitivity of about 11 nm / 1000 °C, figure of merit of 0.218 / oC and a very small full width at half maximum of about 0.049 nm. The proposed annular photonic crystals temperature sensor could present a novel method to overcome the limited performance of the planar photonic crystals temperature sensors besides the possibility of using in many potential filtering applications.