High-sensitivity temperature sensor by coupling two-dimensional photonic crystal waveguide with dual microcavities

摘要

We propose a photonic crystal dual-resonant microcavity and waveguide-coupled temperature sensor structure. The resonant characteristics of photonic crystal microcavities are simulated by finite-difference time-domain method. Due to the positive thermo-optic effect of silicon and the negative thermo-optic effect of SU-8 photoresist, a resonant wavelength shift is detected for temperature sensing in the opposite direction, which significantly improves the sensitivity of the sensor. Simulation results highlight that the sensitivity of the temperature sensor is 124.69 pm/℃, the temperature measuring range is ～150℃, and the limitation of the temperature sensing area is reduced. The sensor can be integrated to lab-on-chip and system-on-chip to achieve real-time temperature measurement in different microregions.