使用双波带板径向剪切干涉仪检测非球面透镜

为了实现对光学非球面的低成本在线测量,在比较和分析现有非球面检测技术的基础上,设计并制作了一种小型径向剪切干涉仪用于检测非球面透镜。基于波带板可以聚焦成像的原理,该干涉仪采用不同焦距的双波带板产生径向剪切干涉。波带板由工业缩微矢量图制版技术设计和制作而成,并通过实验验证了该波带板的聚焦精度。采用傅里叶变换条纹相位分析法对干涉条纹进行处理,计算出波相差和波面面形。实验中给出了平面波光束经过一个非球面透镜后的波面面形检测结果和误差分析,使用该技术对标准非球面进行测试,波差峰谷值(P-V)达到了λ/5的精度,均方差(RMS)达到λ/10的精度。结果表明,该干涉仪具有体积小、抗干扰能力强等特点,适用于对小型非球面透镜进行在线检测。

Aspheric lens testing by miniature radial shearing interferometer

Aspheric surface testing technique with radial shearing interferometer has been developed. The principle of the measurement is based on the radial shearing interference in which the measuring wavefront from the entire mirror surface under test is referred to that of the central part. Zone plates are used to construct radial shearing interferometer because of its stability and simplicity. Zone plates were designed and fabricated by photographic processing, which is used as radial shearing devices. Radial shearing interferogram are detected by a CCD camera and processed by a PC computer. Fringe phase of shearing interferogram is evaluated by Fast Fourier transform (FFT) algorithm and testing wavefront is reconstructed. The experiments showed that this stable interferometer can be applicable to the in-process measurement for aspheric lens, and some errors of measurement were discussed.