parameter for coating: MgF2 single-layer antireflection film-0 degrees Lower than 2.5% reflection over wavelength ranges 400 to 750 nm; Lower than 1.5% reflection over wavelength ranges 500 to 620 nm. MgF2 single-layer antireflection film-45 degrees Lower than 6% RS over wavelength ranges 400 to 750 nm; Lower than 3% Ravg over wavelength ranges 400 to 750 nm; Lower than 0.5% Rp over wavelength ranges 400 to 750 nm. parameter for prism: Material:H-K9L,H-BaK7,etc; Surface quality:40-20/20-10; Dimensional tolerance:plus or minus 0.05mm; Surface flatness:1/2 lambda; Angle tolerance:plus or minus 2 arc min.