Abstract: In order to realize alignment of the large aperture catadioptric 355 nm laser receiving system, a local specific alignment method is put forward. Two-mirror system with wavelength of 355 nm, 632.8 nm mirrors and consistent mirror spacing uses 4D interferometer self-collimation debugging method. The lens group adopts self-collimation detection optical path debugging method composed of 355 nm laser and interferometer front lens. After alignment, the root mean square (RMS) of wave aberration in two-mirror system is 0.2026λ, which satisfies the design requirement of 0.2λ (λ is 632.8 nm). After the alignment of lens group, the difference between theoretical and self-collimation detection rear cut-off distances is in the range of design index tolerance. After the combination alignment of the two-mirror system and focusing lens group system, the focus of image and that of object are consistent, and the alignment of receiving system meets the design requirements. The proposed method reduces the difficulty of system alignment and shortens the system alignment cycle.

Key words: laser techniques, optical alignment, self-collimation alignment, large aperture catadioptric system, 355 nm laser