Design of an optical mechanical accelerometer with optical frequency comb enhancement for sensitivity improvement

Micro-nano photomechanical accelerometers have the advantages of small size, high sensitivity, low cost, high reliability, low power consumption, and can be mass-manufactured, and are widely used in automotive, industrial production, aerospace and many other fields. However, the sensitivity of accelerometers is not sufficiently high. The utilization of optical frequency combs can effectively enhance the sensitivity of accelerometers and also improve their precision. Based on the mechanical properties of Si racetrack resonator, a kind of accelerometer with fixed beam structure is designed by using semiconductor micro-nano machining technology. The output signal of accelerometer based on fixed beam structure has a linear relationship with the measured acceleration intensity, and an acceleration sensor structure is proposed. By analyzing the spectral characteristics of the racetrack microring resonator, the acceleration value of the system is measured by using the offset characteristic of the output spectrum under the action of acceleration. Simulation results show that the sensitivity of the system can reach 150 pm /g. In addition, a method based on frequency comb source is proposed, which reduces the uncertainty of resonant frequency difference and improves the accuracy of acceleration determination compared with a single input light source. This structure provides a theoretical basis for the preparation of highly integrated and low-cost micro-acceleration sensors.