A Wide Range of Optomechanical Temperature Sensing Based on Silicon Nitride Membrane Resonator

Small-volume, low-power temperature sensor chips play an important role in integrated circuits and the Internet of Things. Therefore, we proposed an optomechanical temperature sensor based on a suspended (silicon nitride) $\text{Si}_{3}\mathrm{N}_{4}$ membrane resonator. We use the photothermal effect to achieve the resonant excitation of the resonator and detect the resonator frequency information by laser interferometry. Temperature changes the stress of the membrane resonator and thus changes its resonant frequency, based on which temperature detection is achieved. The prepared resonator sample exhibits a mechanical quality factor of $3.68\times 10^{\underline{5}}$, and the narrow linewidth brought by the high quality factor is conducive to the frequency shift detection of temperature. By providing a wide range of temperature conditions of 30K-290K with low-temperature equipment, we used the membrane resonator to achieve a temperature sensitivity of 23.57Hz/K. This sensing platform has laid a certain foundation for the development of a wide range of optical temperature sensor chips.