He Rui Optics'plano-concave lenses, these lenses have negative focal lengths and can be used to diverge collimated beams. In this case, the curved surface of the lens should face the source to minimize spherical aberration. In addition, they can be employed to offset the effects of spherical aberration caused by other lenses in an optical system.
| Material | optical glass,N-BK7 Glass, Fused Silica, sapphire,Si,Ge,CaF2,LiF,BaF2,Crown glass，Pyrex, .. |
| Dimensions | 3-400mm |
| Dimension Tolerance | ±0.01mm |
| Thickness Tolerance | ±0.01mm |
| Center thickness | >1mm |
| Focal Length tol. | ±1% |
| Centration | 3 arc minutes |
| Surface Quality | 80/50 60/40 40-20 20-10 |
| Clear Aperture | >90% |
| Wavelength Range | Substrate Material |
| 180nm-8.0μm | Calcium Fluoride (CaF2) |
| 185 nm-2.1 um | UV Fused Silica |
| 200 nm- 5.0 um | Sapphire |
| 200 nm- 6.0 um | Magnesium Fluoride (MgF2) |
| 220 nm to >50 um | CVD Diamond Windows |
| 230 nm- 1.1 um | UV Fused Silica. Textured Antireflective surface |
| 250 nm- 1.6 um | UV Fused Silica, for 45° AOI |
| 250 nm- 26 um | Potassium Bromide (KBr) |
| 350 nm- 2.0 um | N-BK7 |
| 600 nm- 16 um | Zinc Selenide (ZnSe) |
| 1.2- 8.0 um | Silicon (Si) |
| 1.9- 16 um | Germanium (Ge) |
| 2- 5 μm | Barium Fluoride (BaF2) |
