The focus of the plano concave lens is negative, it can make the collimation incident light divergence. And only engender the virtual image. The plano concave lens usually be used in the modern optics system to expand the beam of light or add the length of the focus.
Item
Specifications
Material
Fused Silica; N-BK7（H-K9L) or others
Diameter tolerance
+0.0/-0.2mm
Thickness tolerance
±0.2mm
Centration
<3min
Focus length tolerance
±2%
Surface quality
60/40
Clear aperture
85%
Bevel(face width×45°)
0.2~0.4mmor specified by customer
Coating
Specified by customer