Meniscus lens, also called convex-concave lens, can be either positive or negative, depending on the relative curvatures of the two surfaces. A negative meniscus lens has a steeper concave surface and will be thinner at the centre than at the periphery. Conversely, a positive meniscus lens has a steeper convex surface and will be thicker at the centre than at the periphery. It is used in conjugation with other lenses to form an optical system, which to make the original lens has longer or shorter focal length. The material can be BK7 Grade A or other equivalent optical glass. AR or NIR coating can be ordered for specific application.

Material--------------------BK7 Grade A or equivalent optical glasses

Design Wavelength-------480-650nm

Diameter Tolerance-------±0.1mm, ±0.15mm for Dia.≥75mm

Paraxial Focus Length-----±2% @546.1nm

Centration-----------------<3 arc minutes

Clear Aperture------------->80%

Surface Figure-------------λ/4 @632.8nm

Surface Quality------------60/40～40/20 scratches and dig

Coatings-------------------Antireflection coatings or NIR coatings

Bevel-----------------------A slight protective bevel