|Type||Biconcave Lenses||Material||BK7,UV FS, CaF2, ZnSe, Sapphire, BaF2 etc.|
|Clear Aperture||>90%||Diameter Tolerance||+0.00/-0.1mm|
|Thickness Tolerance||±0.1mm||Surface Irregularity||λ/4 @ 633 nm (λ/8 optional)|
|Concentricity||3 arcmin||Paraxial Focal Length||+/-2%|
|Chamfer||0.2mm x 45 degree|
Biconcave lenses have equal radii on both surfaces. Biconcave lenses are commonly used in laser beam expanders, optical character readers, viewers. And they are normally used to increase focal lengths in optical systems and in combination with other lenses. Hangzhou Shalom EO offers Custom biconcave lenses upon customers' request.