Large N-BK7 plano-concave lens is used in astronomy industry. We offer large plano concave lenses with materials N-BK7, UV grade fused silica glasses, N-SF2, N-SF5, N-SF6, and B270 etc., We offer the large lenses with AR coating or without coating.
Production capabilities：
| Substrate | N-BK7, JGS1, JGS3, or fused silica glasses, corning 7980, etc. |
| Diameter | 50mm - 500mm |
| Tolerance | +/-0,1mm |
| Thickness tolerance | +/-0.1mm |
| Surface quality | 40-20 or better |
| Surface figure | Lambda/4 |
| Centering | 3 arc mins |
| Bevel | Protective bevel |
| Coating | AR coated or reflective coated @ different wavelengths |
