Plano-concave lens, one of negative lenses, is used to diverge the collimated incident beam. The beam after passing through the lens appears to be emanating from a particular point on the axis(focal point) in front of the lens. It can form virtual image which can be seen through the lens. The materials can be BK7 or UV fused silica. Because of its negative focal length, it is usually used to expand light or increase focal length in optical systems. Plano-concave lenses are commonly used in devices of optical display/image systems, projection optical systems etc. AR or NIR coatings can be order for specific applications.

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