基于相位差法的光学综合孔径望远镜失调检测技术

Misalignment Sensing for Optical Aperture Synthesis Telescope Using Phase Diversity

光学综合孔径望远镜常常因为子望远镜间的失调大于1λ而产生相位差,影响望远镜的分辨能力。基于相位差法的检测技术,主要是利用在焦面和离焦位置上同时采集的一对图像,对光瞳上的相位分布进行恢复,从而得出子望远镜间的微小失调误差。在计算机模拟成像系统的基础上,我们使用有限差分法对波前相位进行了恢复。模拟研究结果表明,相位差法可以较准确恢复出波前相位,检测出失调量。

An optical aperture synthesis telescope such as the Multiple - Mirror Telescope will suffer from phase errors unless the segments are aligned to within a small fraction of a wavelength. As an optical misalignment sensing technique, phase diversity can estimate the pupil phase from pairs of simultaneously recorded focused and defocused images, then the misalignment error is obtained. The image - forming system have been simulated by computer, and the unknown wavefront have been estimated by using the method of finite differences. Simulation results show phase - diversity method can accurately retrieve the wavefront, and sense misalignment error.