A novel progressive wave gyroscope based on acousto-optic effects

Abstract

We propose and numerically investigate a brand-new, high-sensitivity progressive wave gyroscope based on acousto-optic effects for the measurement of rotational angular velocity. Unlike the traditional surface acoustic wave (SAW) gyroscope, which uses shifts in the SAW frequency to characterize the rotational angular velocity, this study uses acousto-optic effects to detect changes in refractive index caused by mechanical strain, measuring the angular velocity by the output optical power intensity of the optical waveguide. The three-dimensional finite element analysis method is utilized to build an SAW excitation model and optical detection model. We show that the sensitivity of the SAW gyroscope is highly dependent upon geometric parameters of the structure and that the mechanical strain induced by the progressive wave of the SAW can be effectively measured by the optical power intensity under the action of external angular velocity. The superiority of the proposed structure is substantiated by its achievement of a theoretical sensitivity of 1.8647 (mW/m2)/(rad/s) and high impact resistance of 220,000 g. By means of normalization, the sensitivity of the proposed structure can be enhanced by four orders of magnitude compared to the traditional SAW gyroscope. The novel structure combines the advantages of both conventional microscale vibrating gyroscopes and optical gyroscopes, providing a powerful solution for performance enhancement of SAW gyroscopes and, thereby, enabling application in the field of inertial devices.