基于Fabry-Perot腔的光学真空测量技术研究

Research on Optical Vacuum Measurement Technology Based on Fabry-Perot Cavity

基于从头计算理论,对氩气摩尔极化率、摩尔磁化率和维里系数等物理参数进行计算,结合维里状态方程和Lorentz-Lorenz方程建立了气体压力关于折射率的理论参数模型.利用基于Fabry-Perot腔的光学真空测量装置,通过精确测量Fabry-Perot腔内激光的谐振频率变化,获得气体折射率和气体压力,在10^(5) Pa时,折射率相对测量不确定度为1.8×10^(-11),气体压力相对不确定度为4.4×10^(-6).对比分析基于Fabry-Perot腔的光学真空测量装置与电容薄膜真空计获得的测量压力,结果表明基于Fabry-Perot腔的光学真空测量方法具有较高的稳定性和准确性.

Based on the ab initio theory,the physical parameters such as molar polarization,molar susceptibility and Virial coefficient of argon gas were calculated,and the theoretical parameter model of gas pressure about refractive index was established by combining the Virial equation of state and Lorentz-Lorenz equation.The optical vacuum measuring device based on the Fabry-Perot cavity was used to accurately measure the resonant frequency change of the laser in the Fabry-Perot cavity to obtain the gas refractive index and gas pressure.At 10^(5) Pa,the relative uncertainty of the refractive index is 1.8×10^(-11),and the relative uncertainty of the gas pressure is 4.4×10^(-6).The measured pressures obtained by the optical vacuum measuring device based on the Fabry-Perot cavity and the capacitance film vacuum gauge were compared and analyzed.The results showed that the Fabry-Perot cavity based optical vacuum measuring method has higher stability and accuracy.