▎ 摘　　要

NOVELTY - The filter has a focusing lens, a saturable absorption sheet and a collimating lens. The focusing lens, saturable absorption sheet and collimating lens are placed coaxially in sequence along the direction of light beam transmission, and the focus of the focusing lens and the collimating lens coincide on the saturable absorption sheet. The material of the saturable absorption sheet is crystalline materials such as chromium, vanadium, carbon dioxide, and graphene. USE - Spatial filter. ADVANTAGE - The spatial filteruses a saturable absorption sheet to filter, which used for the exhibition of the exhibition of the pulse amplifier system to improve the signal to noise ratio, refilibrates high frequency noise in space, and uses a saturable absorption sheet to filter does not have a hard edge diffraction, and solve the problem of card light, shock, etc., etc. The filter greatly reduces the difficulty of laser regulation and collimation, and improves the quality of the output beam of the laser. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a spatial filter.