Negative meniscus lenses are designed to minimize spherical aberration. The lenses have a convex face and a concave face where the concave face has the greater radius of curvature. Used it together with other lenses, the negative meniscus lens will decrease the NA of optical system. Negative meniscus lens is a common component in beam expanding application. N-BK7 is a very common glass for this lens.
Manufacture capabilities:
| Diameter range | 2mm to 500mm |
| Diameter tolerance | +/-0.02mm |
| Thickness tolerance | +/-0.05mm |
| Surface quality | 60-40 or 40-20 or better |
| Flatness | Lambda/4 or better |
| Centering | 3 arc mins |
| Bevel | Protective bevel |
| Coating | AR coated or without coating |
| Certificate | RoHs |
