摘要
Laser resistance and stress-free mirrors,windows,polarizers,and beam splitters up to 400 mm×400 mm are required for the construction of the series SG facilities.In order to improve the coating quality,a program has been in place for the last ten years.For the small-aperture pick-off mirror,the laser-induced damage threshold(LIDT)is above 60 J/cm2(1064 nm,3 ns),and the reflected wavefront is less thanλ/4(λ=633 nm).The Brewster-angle polarizing beam splitter(Φ50×10 mm)shows the best LIDT result,up to 29.8 J cm 2(1064 nm,10 ns)for a p-polarized wave in the 2012damage competition of the XLIV Annual Boulder Damage Symposium.For the larger-aperture mirror and polarizer,the LIDT is above 23 J cm 2(1064 nm,3 ns)and 14 J cm 2(1064 nm,3 ns),respectively.The reflected wavefront is less thanλ/3(λ=633 nm)at the used angle.
Laser resistance and stress-free mirrors, windows, polarizers, and beam splitters up to 400 mm × 400 mm are required for the construction of the series SG facilities. In order to improve the coating quality, a program has been in place for the last ten years. For the small-aperture pick-off mirror, the laser-induced damage threshold(LIDT) is above 60 J/cm2(1064 nm, 3 ns), and the reflected wavefront is less than λ/4(λ = 633 nm). The Brewster-angle polarizing beam splitter(Φ50 × 10 mm) shows the best LIDT result, up to 29.8 J cm 2(1064 nm, 10 ns) for a p-polarized wave in the 2012damage competition of the XLIV Annual Boulder Damage Symposium. For the larger-aperture mirror and polarizer, the LIDT is above 23 J cm 2(1064 nm, 3 ns) and 14 J cm 2(1064 nm, 3 ns), respectively. The reflected wavefront is less than λ/3(λ = 633 nm) at the used angle.
