新型椭球形窗口零位检测技术研究

Research of Null Optics Testing for Elliptical Windows

椭球形窗口的检测技术严重阻碍其成功应用。首先简要介绍了目前普遍使用的非球面检测技术,并针对椭球形窗口大倾斜、大偏心、深非球面的特点,基于零位补偿检测法原理,设计了一种适合椭球形窗口检测的改进型Offner零位补偿检测系统。检测系统包括补偿镜、场镜和标准球面参考镜,检测系统工作原理为:干涉仪出射平行光线通过补偿镜及场镜产生修正波前,通过椭球形窗口照射到标准球面反射镜,并按原光路返回与参考光线干涉,其干涉结果显示出椭球形窗口的面形偏差。实现了对椭球形窗口的高精度全口径一次检测并给出了完整的设计结果。检测了长径比为1.0,口径为110mm的椭球形窗口,其波前残余波像差均方根值为0.0052λ。设计结果为实际使用提供了一定的参考。

The elliptical windows testing technology has become the biggest block of development. In order to resolve the problem, the present testing technology for the asphere is expressed briefly. For the elliptical windows characterized by large tilt and large eccentricity deep asphere, based on the compensation theory, an improved Offner null testing compensator system for elliptical windows test is designed. The testing system includes compensator lens, field lens and a spherical reference mirror. The principle of Offner＇s refractive null lens testing system is that when parallel light from interferometer passes through the compensator lens and the field lens, correction wavefront is produced. After transmission through elliptical window and reflection of spherical reference mirror, light returns back according the original path and interferes with the reference light. The interference results display elliptical window shape deviation. The null lens testing system is implemented and the whole design results are demonstrated. For the tested elliptical window with fineness ratio of 1.0 and aperture of 110 mm, the root-mean-square （RMS） value of the final residual wavefront error is 0. 0052λ. Design results provide a certain reference to pratical applications.