针对大口径望远镜拼接式主镜,提出一种基于迈克耳孙干涉原理的低相干光源干涉检测系统。应用该系统对拼接子镜间相位失调误差进行实时检测,进而对失调子镜进行相应校正,以实现拼接子镜的共面排布。给出了低相干光源干涉检测系统的具体结构,叙述了干涉检测系统的检测原理,提出应用双中心波长组合低相干光源进行拼接子镜间相位误差检测,分析了系统最低信噪比。结果表明,双中心波长组合低相干光源系统,可以提高低相干光源干涉中心条纹的信号分辨能力,借以提高检测精度,使得低相干光源干涉测量系统对拼接子镜间的相位失调误差进行高精度提取。

For the large aperture telescope with segmented primary mirrors, a low-coherence-source interferometric detection system based on the Michelson interferometric principle was put forward to detect the phase error between the segmented mirrors, correct the misaligned segments and achieve the mirror coplanar. The concrete structure of the interferometric detection system with the low-coherence source was presented, and the detection principle of the interferometric detection system was narrated. Double-center-wavelength combination low-coherence-source light sources were applied to detecting the phase error of the segmented mirrors and the minimum signal-to-noise ratio was analyzed. The result shows that the application of the double-central-wavelength combination low-coherence source light sources system largely raises the ability of signal distinguishing of the center fringe of the interferograms, improves the measurement accuracy, and makes the low-coherence-source interferometric detection system extract the phase error with high precision.