Research And Design Of A Novel Micro Cavity Optomechanical Gyroscope

Gyroscopes,is a type of inertial measurement unit that can measure object angular velocity,which has been widely used in both military and civilian fields such as unmanned driving,aerospace,and missile guidance.The earliest mechanical rotor gyroscope has achieved high performance,but its high cost and large volume limit its application in consumer electronics and internet of things.With the continuous development of micro-nano processing technology,capacitive silicon micro-mechanical gyroscopes based on the Coriolis effect have occupied the market in consumer electronics due to their unique advantages of low cost and small size,but their performances are poor and can only meet low-precision application scenarios.Therefore,researching and developing low-cost,small-volume,and high-precision gyroscope technology solutions have important scientific and application values.In order to improve sensitivity of traditional capacitive silicon micro-mechanical gyroscope,a new micro-gyroscope structure based on the optomechanical system is designed in the paper.The detail of simulation is numerically investigated and layout design,processing,and initial testing are carried out.The main research contents and innovative achievements of this thesis are as follows:Based on the theory of silicon micro-mechanical gyroscopes using the Coriolis effect and the relevant knowledge of the cavity optomechanics in 2D photonic crystal slabs,the working principle of a micro-gyroscope based on cavity optomechanics is theoretically derived,and structural parameters optimization and theoretical performance analysis are completed through simulations.The support,drive,and detection structures of the micro-gyroscope are designed based on the theoretical derivation,and the COMSOL simulation software is used to analyze the steady-state,characteristic frequency,harmonic response,and photonic crystal optical resonance of the design structure.A new micro-gyroscope structure based on the cavity optomechanics system is designed,and the physical structure parameters are optimized based on simulations to improve the overall sensitivity.The sensitivity of the gyroscope can reach 122.2 m V/（°/s）,and the angle random walk can reach 0.66°/h^1/2.The design method of using metal layers for electrical driving and isolation grooves for potential isolation is adopted,and the array layout of the gyroscope chip is drawn and processed,and the morphology of the gyroscope chip is characterized.Through multiple explorations of the chip processing process,the processing accuracy errors of the metal layer and etching layer are optimized and adjusted,and a complete gyroscope chip structure sample is finally obtained.The processing completed gyroscope chip parameters are calibrated and the morphology is characterized using two characterization methods:scanning electron microscopy and optical microscopy.A functional and performance testing scheme for the micro-gyroscope chip based on the cavity optomechanics system is constructed,including cavity optomechanics system performance testing,electrostatic drive testing,and external angular velocity detection sensitivity testing.The basic optical,electrical,mechanical characteristics and angular velocity detection sensitivity performance of the micro-gyroscope chip based on the 2D photonic crystal cavity optomechanics system are preliminarily tested and studied.