在用刀口检验凸双曲面反射镜时,一般采用传统的Hindle球检测法,但是在许多仪器中,需要曲面反射镜全口径使用,因此,Hindle球检测法是不合适的。此外,在很多情况下,刀口到待检非球面的距离很长,从而降低了刀口检验精度。为了解决这些问题,结合口径Φ=120mm的凸双曲面的检测,在分析了传统检验方法的基础上,提出了有限距离球面波入射的凸非球面透射补偿检验方法。从设计结果上看,它缩短了刀口到待检非球面的距离,获得高精度补偿。实践表明,这种方法不仅能够提高加工效率,而且提高了加工精度,实际加工完成后,这块凸双曲面的RMS值达到了λ/60。

When testing convex hyperboloid with a knife-edge device, the Hindle testing method which is a traditional testing method is general adopted. However, the whole surface is always used in many devices, Hindle testing method is not suitable . Besides, in most cases the overlong distance from knife edge to the aspheric surface to be tested will decrease the precision of the knife-edge testing. In order to solve the problems, a new method of convex aspheric surface using lens for compensational tests in the condition of the beam incidence at a distance is discussed with a diameter of 120mm lens in details. According to the optimization and simulation result, it shortens the distance from the knife-edge to the aspheric surface to be tested and obtains higher compensation precision. The practice shows that the method promotes not only work efficiency but also precision machining and the RMS of the aspheric surface of the lens reaches λ/60 after fulfillment.