用于加速度计的硅基拉链光子晶体腔光机系统

Silicon-Based Zipper Photonic Crystal Cavity Optomechanical System for Accelerometers

基于光子晶体微腔的腔光机加速度计将机械谐振子及高品质因数光子晶体腔相结合,其中的机械振子在机械震荡模式下对微弱力/位移敏感的特性,可以实现极低的噪声水平,理论上能够达到标准量子噪声极限,是高精度加速度计的重要发展方向。对拉链式光子晶体腔光机加速度计的原理和结构特点进行分析,设计了一种应用于加速度计的硅基拉链式光子晶体腔和机械振子结构。分析了拉链腔的结构参数对光学Q值的影响,通过调节结构参数将光腔的谐振频率控制在195 THz附近,并分析了机械振子和光腔的机械谐振特性,光腔的有效质量为30 pg,加上机械振子后有效质量为3.1 ng,光机耦合率达到GHz/nm量级,为基于硅基拉链腔加速度计的制造和表征提供了指导。

The optomechanical cavity accelerometer based on photonic crystal microcavity combines the mechanical resonator with the high-quality factor photonic crystal cavity,and the mechanical vibrator is sensitive to weak force/displacement in the mechanical vibration mode,which can achieve extremely low noise level and theoretically reach the standard quantum noise limit,which is an important direction for the development of high-precision accelerometer.This paper analyzes the principle and structural characteristics of the zipper type photonic crystal cavity optical-mechanical accelerometer,and designs a silicon-based zipper type photonic crystal cavity and mechanical vibrator structure for accelerometer.The influence of the structural parameters of the zipper cavity on the optical Q factor is analyzed in detail.The resonant frequency of the optical cavity is controlled around 195 THz by adjusting the structural parameters,and the mechanical resonance characteristics of the mechanical vibrator and the optical cavity are analyzed.The effective mass of the optical cavity is 30 pg,plus the effective mass of the mechanical vibrator is 3.1 ng,and the opto-mechanical coupling rate reaches the order of GHz/nm,which provides guidance for the manufacture and characterization of the silicon-based zippercavityaccelerometer.