A Chip-scale Magnetic Field Sensor Based on Frequency Readout Cavity Optomechanical System

In this paper, the working principle of cavity optomechanical system is analyzed, and a new chip-scale magnetic field sensor based on frequency readout cavity optomechanical system is proposed. The relationship between the magnetic field and displacement of the mechanical part of the new chip-scale magnetic field sensor is verified, the structure and parameters of the new chip-scale magnetic field sensor are simulated and designed, the optical characteristics of two-dimensional photonic crystal microcavity are simulated and analyzed, and the mechanical resonant frequency of the cavity affected by the displacement and the input laser wavelength and intensity is demonstrated. Then, the whole magnetic field sensor is simulated and analyzed. The results show that when the input laser intensity is 199µW, the sensitivity is 7.9Hz/µT. The new chip-scale magnetic field sensor simulated in this paper has important application value in the fields of navigation, positioning, magnetic imaging, medical imaging and environmental monitoring.