五棱镜扫描法检测大口径近红外干涉仪准直波前

Measurement of the Wavefront Collimation of a Large Aperture Near-Infrared Interferometer Using a Scanning Pentaprism System

为了保证大口径近红外干涉仪的测试精度,必须严格控制其出射波前的准直性。采用五棱镜扫描系统将干涉仪的出射波前分割成若干个子波前,记录每个子波前在CCD上所成光斑质心的相对位置,计算得到各个子波前的法线方向以重构被测波前,从而实现对出射波前准直性的检测。实验测量了210 mm口径的近红外干涉仪准直物镜水平方向上的出射波前,计算重构了被测波前。分析了实验系统误差对于测试结果的影响。该方法成本低、精度高,特别适用于大口径近红外波前的准直性检测。

The wavefront collimation of the large aperture near-infrared interferometer must be controlled strictly. Scanning pentaprism system is introduced to divide the wavefront of the interferometer into a series of sub-wavefronts, and the relative positions of the spot centroid according to every sub-wavefront are recorded on the CCD camera.The normal directions of every sub-wavefront are obtained to reconstruct the tested wavefront,thus the collimation test of the wavefront can be realized.The wavefront in the horizontal direction of the collimation lens of a 210 mm aperture near-infrared interferometer is tested and reconstructed.The effect of system error on the experimental results is analyzed.This method is of low cost and high accuracy,and is particularly applicable to the collimation test of a large aperture near-infrared wavefront.