干涉零位补偿检验研究

Study on Interference Null Compensator Testing

零位补偿检验是现代光学用于检测非球面的主流方法。根据实际检测需要,提出既可进行补偿检验,又可进行干涉检验的一种新型干涉零位补偿检验方法。干涉零位补偿检验的原理是:在零位补偿检验的基础上,将零位补偿系统的第一面改为与激光点光源同心的参考面,从同心参考面反射回来的参考波面与通过零位补偿检验系统的待检非球面反射回来的待检波面相干涉实现干涉零位补偿检验的目的。依据三级像差理论,设计了零位补偿检验的光学系统,给出像差理论分析和实际设计评价结果,当待检非球面镜的孔径角2u小于1 4.5时,系统的剩余波像差优于λ/170。通过对该方法进行原理性实验,充分证实,干涉零位补偿检验是行之有效的。

Null testing is the main measurement for aspheric surface in modern optical testing. In order to improve null testing, a novel measurement which combines compensator and interference is proposed. The principle of the method is that the radius of the first surface of the compensator is chosen to equal the distance between surface and laser point of interference. The reference wavefront reflected from the concentric surface inferred with the wavefront from the aspheric surfaces under test to accomplish the interference null testing. Base on third-order aberration theory, interference null testing system is designed and the residual aberrations are calculated. The wavefront abberation of designed system is better than λ/170 , if the relative aperture is smaller than 1/4.5. By means of theoretic test, this measurement is proved to be available for testing aspheric surface.