高精度标准镜支撑结构的研究与设计

为了保证高精度光学元件面形检测精度，必须对干涉仪标准镜自身的面形精度进行严格控制。在考虑标准镜自重的情况下，采用有限元方法研究了不同胶点数量及分布形式、不同的镜框支撑方式对参考面面形精度的影响。根据研究结果，针对球面标准镜面形精度要优于/40的要求，设计了口径150mm的标准镜的支撑方式，采用123点胶接、镜框底面六点的挠性支撑方式，经有限元分析得到:参考面面形的PV值为7.36nm，RMS值为1.52nm；并验证了温度变形较自重变形很小。结果表明，各项指标满足设计要求，证明了结构设计的合理性。

Investigation and design for structure of high-precision reference mirror

In order to ensure the measuring precision of high accuracy optical, the accuracy of the interferometer reference mirror must be controlled strictly. The influences of different number of adhered points and point distribution, and different support schemes on the shapes of reference mirror were investigated by means of finite element method under gravitational conditions. In order to achieve the peak to valley(PV) value of reference sphere mirror which is better than /40, a kind of support structure of 150 mm reference mirror was designed according to the results of research. The experimental results by means of finite element method indicate that the peak to valley (PV) value and root mean square (RMS) value of the reference surface are only 7.36 nm and 1.52 nm by support scheme with 123 distributed and six-points flexible support, and the thermal deformation is less than gravity deformation. These results demonstrate that all targets validate the rationality of structure and it can well satisfy the requirements.