Meniscus Lens
 
Meniscus lenses can be used with another lens to produce longer or shorter focal lengths. These lenses do not introduce additional spherical aberration or coma in the systems.
 

Material:                        BK7 Optical glasses,CaF2,BaF2, MgF2,Ge,Si,Fused Silica

Diameter Tolerance:     +0.0/-0.02mm

Thickness Tolerance:    ± 0.01mm

Surface Accuracy:        λ/4 @632.8nm

Surface Quality:           20-10

Centration:                  1′

Clear Aperture:            > 90%

Bevel:                          0.2mm×45°

Coating:                      user-defined