为了检测长光程情况或多组分光学镜头逐片装校中的波面,提出一种以会聚光波直接作为干涉测试光源的会聚光移相剪切干涉方法,阐述了基于迈克耳孙干涉仪原理的会聚光横向剪切干涉光路,建立了会聚光横向剪切波面的数学表达式,并与一般横向剪切干涉相比较,分析了剪切量和波面偏移量的特征,且引入移相干涉技术求取剪切波面。结果表明,会聚光横向剪切移相干涉测试,能够实时测试会聚光的波面质量,峰谷值(PV)的重复性为0.022λ,均方根(RMS)值的重复性为0.014λ,并与Zygo干涉仪的测量结果进行了对比,验证会聚光剪切移相干涉的可行性。

For detecting wavefronts from the system with long optical path or multi-component lens with one by one aligning, the phase-shifting lateral shearing interferometry of convergent beam with the convergent beam as light source for interferometry is proposed, which is based on Michelson interferometer. The mathematical expression of the laterally shifted wavefront of convergent beam is established and compared with that of general lateral shearing interferometers. The shearing and wavefronts displacement are analyzed, and the phase-shifting interferometry is adopted to obtain the sheared wavefronts. The results show that the lateral shearing phase-shifting interfermetry of convergent beam can measure the real-time wavefronts of convergent beam with repetitions of peak-valley (PV) value and root-mean-square (RMS) of 0.022λ and 0.014λ respectively. The experimental results are compared with that by Zygo interferometer, which proves the validity of the proposed technique.