离轴非球面反射镜的装调方法

An Alignment Method of Off-Axis Aspheric Mirror

为了在光学装调中保证单件离轴非球面的精确定位，需要对其6个自由度进行严格控制，尤其要对影响离轴非球面装调最重要的离轴量和离轴角这两个自由度加以严格控制。现有离轴非球面加工和检测中，对这两个特殊参数难以给出精确数值，从而难以实现离轴非球面的精密光学装调。通过运用离轴反射镜的曲率半径中心像与工装基准光轴之间的变化规律，采用精密测量法实现对离轴量和离轴角的精确测量。装调实验证明，利用这一测量法，光学装调出的离轴非球面可达到离轴量0．05mm和离轴角10″级的精度，检测出的镜面波像差均方根（RMS）为0．022（λ=632．8nm），使该离轴非球面获得了理想的像质，实现了精确装调。

In order to realize the accurate position of an off-axis aspheric surface in optical alignment, it is necessary to strictly control the six degrees of freedom, especially the two degrees of freedom that affect lateral displacement and tilts angle. But it＇s very difficult to obtain the above two accurate values using general off-axis aspheric surface measurement technique, so it＇s same difficult to realize its precise alignment. The article introduces a new method that applying the close relationship between the center image of radius of curvature and the optical axis of the self- regulating instrument, and by using the precise measurement, the purpose of measuring lateral displacement and tilts angle is achieved. Experiments show that the error of lateral displacement is less than 0.05 mm, the error of tilts angle is less than 10＂, and the wave aberration root mean square is equal to 0.02λ （λ= 632.8 nm）. It can obtain the perfect image and realize the precise alignment of the off-axis aspheric mirror by using this method.