|Type||Bi-Concave 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 has equal radii on both surfaces, the biconcave lenses are common used in laser beam expanders, optical character readers, viewers. And it is normally used in to increase focal lengths in optical systems and combination with other lenses. Custom biconcave lenses are provided upon customer’s request.