The invention provides an anti-reflection method for a beam sampling
grating in an intense
laser system. The method comprises the following steps: to begin with, preparing a sub-
wavelength grating template on a
fused quartz substrate through a holographic
ion beam
etching method; dropping a little PUA UV imprinting
photoresist on the sub-
wavelength grating template, and then, covering a PET film on the PUA; curing the PUA through UV
irradiation, and separating the cured PUA from the grating template to obtain a sub-
wavelength grating soft template; clearing the surface of the beam sampling grating, and then,
spin coating PMMA imprinting
photoresist on the surface; covering the sub-wavelength grating soft template on the PMMA, wherein soft template grating fringe direction can be parallel, vertical or form angle with the fringe direction of the beam sampling grating; clamping the two through a clamping mechanism and placing the two into a baking oven for heating and curing; separating the sub-wavelength grating soft template from the substrate, and forming a sub-wavelength grating on the PMMA; then, removing bottom residual
photoresist of the PMMA grating through
oxygen plasma ashing; by utilizing a to-the-bottom PMMA subwavelength grating
mask, carrying out CHF3 reaction
ion beam
etching; and finally, carrying out cleaning to remove residual photoresist to obtain the beam sampling grating having an anti-reflection effect.