四通道超稳腔的振动分析及热分析

Analysis of Vibration Sensitivity and Thermal Time Constant of Four-channel Ultrastable Cavity

镱原子光钟是当前稳定度最好的光钟,其稳定度已经进入10^(-19)的量级。依托于高精度的镱原子光钟,可以开展广义相对论的检验以及测地学等领域的科学和应用研究。镱原子光钟研制过程中需要用到多种频率的光,所以针对这些激光的频率控制是镱原子光钟研制的一项关键技术问题。本文针对钟激光以外其他四种激光的频率控制要求,以一个四通道超稳光学腔设计作为其频率锁定方案。利用有限元分析方法,得到了超稳光学腔处于最佳支撑位置处的振动敏感度和温度敏感度。分析结果表明:在最佳支撑位置处,光学腔超稳在竖直方向上的振动敏感度为4.0×10^(-9)/g,热时间常数为53 h。对周期为24 h的典型实验环境温度293.15±1 K的条件下,计算获得的温度敏感度为1.3×10^(-4)。该四通道超稳光学腔能够同时满足镱原子光钟系统中除钟激光外其他激光的频率稳定度要求。这种简化的四通道超稳腔稳频设计方案,为今后镱原子光钟的小型化、集成化设计提供一种新技术尝试。

Ytterbium(Yb)atomic optical clock is currently the most stable optical clock,and its frequency stability has reached 10-19 level.Based on the high-precision Yb atomic optical clock,scientific and applied research in the fields of general relativity testing and geodesy can be carried out.Laser of multiple wavelengths are used in the Yb atomic optical clock,so the frequency control of these lasers is a key technical issue.A four-channel optical ultrastable cavity is carried out,according to the frequency control requirements of four lasers(expect clock laser)in the Yb optical clock system.Then the finite element analysis method is used to obtain the vibration sensitivity and temperature sensitivity of the ultrastable cavity at the best supporting position.The analysis results show that the vertical vibration sensitivity of the optical cavity at the best supporting position is 4.0×10^(-9)/g,and the thermal time constant is 53 h.The temperature sensitivity of 1.3×10^(-4) is obtained for the ultrastable cavity,when the ambient temperature varies around room temperature,with a period of 24 h and a amplitude of 1 K.These results show that the four-channel ultrastable optical cavity we design can meet the requirements of the frequency stabilization for four lasers(except clock laser)in the Yb optical clock system.The scheme of using simplified four-channel ultrastable cavity for frequency stabilization provides a new technical attempt for the future miniaturization and integrated design of ytterbium atomic optical clocks.