97% for 450 nm 2 m >95% for 2 20 m Substrate UV Fused Silica Surface Flatness (Peak to Valley) @ 633 nm Surface Quality 40 20 Scratch Dig Parallelism <3 arcmin Clear Aperture >90% of Dimension Damage" name="description"/> 97% for 450 nm 2 m >95% for 2 20 m Substrate UV Fused Silica Surface Flatness (Peak to Valley) @ 633 nm Surface Quality 40 20 Scratch Dig Parallelism <3 arcmin Clear Aperture >90% of Dimension Damage" property="og:description"/> 97% for 450 nm 2 m >95% for 2 20 m Substrate UV Fused Silica Surface Flatness (Peak to Valley) @ 633 nm Surface Quality 40 20 Scratch Dig Parallelism <3 arcmin Clear Aperture >90% of Dimension Damage" name="twitter:description"/>