Overview: Star Optic provides high precision windows fabricated from RoHS compliant N-BK7 glass which is typically chosen in the visible and near infrared range due to its excellent transmission in the spectrum. Other materials and various optical coating options are also available for use in a large variety of laser and industrial applications.  General Specifications of Uncoated N-BK7 Windows: Material | N-BK7 | Wavefront Distortion | <λ@633nm per 25mm (Standard) <λ/10@633nm per 25mm (High Precision) | Surface Quality | 60/40 scratch-Dig (Standard) 20/10 Scratch-Dig (high precision) | Dimension Tolerance | +0/-0.2mm | Thickness Tolerance | ±0.2mm | Parallelism | <1 arc minute (standard) <10 arc seconds (high precision) | Clear Aperture | >90% | Chamfer | Protective<0.5mmx45° | Coating | Uncoated, available | Standard Products of Uncoated N-BK7 Windows: Part No. | Material | Diameter (mm) | Thickness (mm) | Grade | Coating | WIN1003 | N-BK7 | 10.0 | 3.0 | Standard | Uncoated | WIN1203 | N-BK7 | 12.7 | 3.0 | Standard | Uncoated | WIN1503 | N-BK7 | 15.0 | 3.0 | Standard | Uncoated | WIN2003 | N-BK7 | 20.0 | 3.0 | Standard | Uncoated | WIN2503 | N-BK7 | 25.4 | 3.0 | Standard | Uncoated | WIN3003 | N-BK7 | 30.0 | 3.0 | Standard | Uncoated | WIN3803 | N-BK7 | 38.1 | 3.0 | Standard | Uncoated | WIN5006 | N-BK7 | 50.8 | 6.35 | Standard | Uncoated | WIN1006 | N-BK7 | 10.0 | 6.35 | High Precision | Uncoated | WIN1206 | N-BK7 | 12.7 | 6.35 | High Precision | Uncoated | WIN1506 | N-BK7 | 15.0 | 6.35 | High Precision | Uncoated | WIN2006 | N-BK7 | 20.0 | 6.35 | High Precision | Uncoated | WIN2506 | N-BK7 | 25.4 | 6.35 | High Precision | Uncoated | WIN3006 | N-BK7 | 30.0 | 6.35 | High Precision | Uncoated | WIN3806 | N-BK7 | 38.1 | 6.35 | High Precision | Uncoated | WIN5010 | N-BK7 | 50.8 | 10.0 | High Precision | Uncoated | |