法布里珀罗腔振动敏感度的分析

Analysis of the Vibration Sensitivity of Fabry-Perot Cavities

法布里珀罗腔被用作高稳定光频振荡器的频率参考。腔长的稳定性会受到由于振动导致的腔体形变的破坏,进而使激光器产生频率噪声。通常采用有限元分析来考察光腔在任意加速度下的弹性形变。推导出了由腔镜的位移和倾斜带来的腔长变化的通用表达式,表达式明确地给出了光腔形变和其导致的振动敏感度之间的关系。根据该方法,分析了一种水平光学腔的振动敏感度,并且通过优化支撑结构降低了光学腔对振动的敏感性。此外,设计了一种小型振动平台,可以在三个相互垂直的方向对腔体施加振动。

Ultrastable optical oscillator use Fabry-Perot cavities as their frequency reference. The deformation of cavity induced by the vibration degrades the length stability of the cavity and laser produce frequency noise. Finite element analysis （FEA） is often used to examine the deformation of the cavity at arbitrary acceleration. A general expression of the change of the cavity length induced by the displacements and tilting angles of the cavity mirrors is deduced. This expression provides the definite connection between the cavity deformation and the vibration sensitivity. Based on this method, it is analyzed that the vibration sensitivity of a horizontal optical cavity, and its sensitivity to vibration can be reduced by optimizing the mounting configurations. In addition, a compact vibration platform that is able to shake the optical cavity in three orthogonal directions is designed.