The LF7639-F is a spherical lens with a base shape of a circle, sourced from the reputable vendor Thorlabs. This lens is a ZnSe (Zinc Selenide) material type, specifically identified as 'znse connolly'. The lens has a diameter of 25.4 mm and a thickness at the edge of 4.1 mm, while the center thickness is 4 mm.
The effective focal length (EFL) of this lens is -500mm, indicating that it is a negative meniscus lens. The first radius of curvature (r1) is 146.1 mm, and the second radius of curvature (r2) is 119 mm. The back focal length (bfl) is -492 mm. The lens does not have an inner or outer radius.
This lens is designed to operate at a wavelength of 10600 nm. It comes with anti-reflection coatings on both the front and back surfaces, specifically 'tho znse-arced 8-12'. This coating is optimized for the 8-12 µm spectral range.