面向谐振式微光学陀螺应用的球形谐振腔DQ乘积优化

基于谐振式光学陀螺高灵敏度、低成本与微型化的发展需求, 为了实现高灵敏度的谐振式微光机电陀螺, 提出了以集成光学微谐振腔领域里高Q值、大直径谐振腔的制作为目标, 应用方向为谐振式光学陀螺的球形光学微谐振腔核心敏感单元. 在实验中以氢火焰作为热源采用熔融法制备球形光学微谐振腔. 通过调节氢气的流量控制氢火焰热源面积, 制备了不同直径(300-2200 μm)的球形谐振腔, 分析了球形谐振腔Q 值、DQ乘积、陀螺灵敏度与谐振腔直径D的对应关系及其原因, 获得了最优参数的面向谐振式光学陀螺的球形谐振腔敏感单元. D=1260 μm时, 球腔品质因数 Q=7.18×10⁷, 得到的最优陀螺灵敏度约为10°/h, 满足商业级应用的需求, 为芯片级、高精度、低成本的新型谐振式光学微腔陀螺的研究奠定了实验基础.

Optimization of microsphere’s DQ product based on resonant micro-optical gyro

Based on the development of high sensitivity, low cost, high integration and miniaturization demand of the resonant micro-optical gyro(R-MOG), and in order to achieve a resonant micro-optical-mechano-electrical integrative gyro having high sensitivity, a microsphere optical resonator key sensitive element for producting a cavity with high quality value (Q value) and large diameter in the field of integrated optical micro resonator is proposed, for making a resonant micro optical gyro. Microsphere optical resonator is made by means of water-hydrogen flame melting, and the SiO₂ microspherical cavity is formed under the natural cooling and contraction surface tension. Microsphere optical resonator with its diameter D ranging from 300 μm to 2200 μm is fabricated by melting method with hydrogen flame as a heat source through controlling the hydrogen flame’s area by regulating the flow of hydrogen gas. The resonator serves as the key unit of the resonant optical gyro sensitive parts, its Q value and diameter D have direct effect on the performance of the resonant angular velocity sensor. Affect parameters on the performance of the microsphere optical resonator with different diameters is tested and processed to obtain the result. The corresponding relationship among Q value, DQ product, resonant micro-optical gyro’s sensitivity and microspherical cavity diameter D is analyzed, and the reason for them is given. With the increase of microspherical cavity diameter D, the Q value and DQ product reduce after rising first, while the gyro sensitivity goes to rise and fall. Based on the microsphere optical resonator DQ product optimization research, the resonant micro-optical gyro’s key sensitive unit with best parameters is obtained. When the microspherical cavity diameter D varies from 600 to 200 μm, the gyro sensitivity can meet the condition that δΩ <30°/h, which arrives at the tactical level. When the microsphere cavity diameter D is 1260 μm, the Q value of microsphere optical resonator is 7.18×10⁷ and the corresponding optimal limited sensitivity of the resonant micro-optical gyro is almost 10°/h, and this result adequately meets the requirement of business level gyro applications. This work can serve as an experimental foundation in the research of new type resonant micro optical gyro at chip level, high accuracy and low cost, and will also provide a technical reference for further study of high integrated and high precision resonant micro optical gyro.