Fast and high precision alignment of off-axis reflective optical system

Abstract

To realize the fast, high-quality alignment of off-axis reflective system, a computer-aided alignment method based on high-precision extraction of optical axis and high- precision restoration of surface shape of off-axis mirror was proposed. The optical axes of the mirrors are derived by means of a zero-position compensation detection path of the off-axis mirrors, and accuracy is better than 6", realize more rapid and accurate system initial alignment. There propose a surface shape data conversion algorithm, combined with Code V, it can realize the high-precision restoration of measured surface shape data of off-axis mirror in simulation, accurately calculate and separate the influence of shape error and position misalignment on system quality, and realize the fast and high precision alignment of off-axis reflective system. This method is applied to the practical alignment of one off-axis TMA system, wave aberration RMS≤0.084λ(λ=632.8nm) after initial alignment of the system. After only once calculation and alignment, full field RMS≤0.055λ. The experiment results demonstrate that this method is feasible.