1)BK7 Windows High Precision BK7 Windows Specifications Material:BK7 grade A optical glass Diameter Tolerance:+0.0,-0.1mm Thickness Tolerance:?.2mm Clear Aperture:＞80% Parallelism:see the table Surface Quality:20-10 scratch and dig Wavefront Distortion:λ/10Per 25mm Bevel:＜0.25 mm?5? 2)Standard BK7 Windows Specifications Material;BK7 grade A optical glass Diameter Tolerance:+0.0, -0.1mm Thickness Tolerance:?.2mm Clear Aperture:＞80% Parallelism:1' Surface Quality:60-40 scratch and dig Wavefront Distortion:λper 25mm Bevel:＜0.25 mm?5? 3)Fused Silica Windows High Precision Fused Silica Windows Specifications: Material:UV grade fused silica Diameter Tolerance:+0.0, -0.1mm Thickness Tolerance:?.2mm Clear Aperture:＞80% Surface Quality:20-10 scratch and dig Wavefront Distortion:λ/10 per 25mm Bevel:＜0.25mm?5? 4)Standard Fused Silica Windows Specifications: Material:UV grade fused silica Diameter Thickness Tolerance:+0.0, -0.1mm Thickness Tolerance:?.2mm Clear Aperture:＞80% Parallelism:1? Surface Quality:60-40 scratch and dig Wavefront Distortion:λ per 25mm Bevel:＜0.25mm?5? 5)Sapphire Windows Specifications: Material:Anisotropic synthetic sapphire crystal(AI2 O3), Orientation:Random Diameter Tolerance: +0.0, -0.1mm Thickness Tolerance:?0.2mm Clear aperture:＞80% Parallelism:3 arc minutes Surface Quality:80-50 scratch and dig Flatness:λPer 25mm at 633 nm Bevel:＜0.25mm?5? 6)Calcium Fluoride Windows Specifications: Material:Calcium Fluoride single crystal Diameter Tolerance:+0.0, -0.1 mm, Thickness Tolerance:?.2mm, Clear Aperture:＞80% Parallelism:1 arc minute Flatness:λ/2 at 632.8 nm Surface quality:80-50 scratch and dig Bevel:＜0.25mm?5?