• Material: Vacuum Grade CaF₂
• Wavelength Range: 180nm - 8.0μm

Thorlabs CaF₂ Bi-Concave lenses are popular for many applications. Bi-Concave lenses have a negative focal length and are best used to diverge a converging beam. Similar to a Plano-Concave lens, a Bi-Concave lens can diverge a collimated beam to a virtual focus as used in a Galilean type beam expander (see Drawing tab for reference).

Lens kits are available. Please click here for information.