A double concave lens consists of two inward identical curved surfaces with a negative focal length. It can also be used for various applications involving scattering, detection, laser, and fiber optics.

Material: CaF2, MgF2, quartz, K9, etc.

Design wavelength：587.6nm

Central Thickness Tolerance: ± 0.1mm

Dimensional Tolerance: ± 0.1mm

Focal Length Tolerance: ± 1%

Surface Quality: 60/40

Surface Accuracy: λ/10~2λ