Meniscus lens is made by one concave and one convex surface. When the center thickness is thicker than edge thickness, then the lens is positive meniscus lens, or it is negative meniscus lens. The focus of the positive meniscus is plus, it can add the aperture of the positive meniscus lens assembly, and can not add the aberration. The focus of the negative meniscus lens is negative.
Item
Specifications
Material
Fused Silica; N-BK7（H-K9L) or others
Diameter tolerance
+0.0/-0.2mm
Thickness tolerance
±0.2mm
Centration
<3min
Focus length tolerance
±2%
Surface quality
60/40
Clear aperture
85%
Bevel(face width×45°)
0.2~0.4mmor specified by customer
Coating
Specified by
customer