This is the 21-940 model from Edmund Optics, a 50mm Dia. UVFS Aspheric Lens with an effective focal length (EFL) of 50mm and a numerical aperture (NA) of 0.48, specifically designed for UV applications within the 250-425nm range.
The lens is made of HPFS7980 Corning, a high-performance fused silica that offers excellent transmission and resistance to thermal shock. The aspheric design of the lens helps to reduce spherical aberration, providing superior image quality.
The lens has an inner radius of 0 and an outer radius of 0, with a diameter of 50mm. The edge thickness is 4.01mm, and the center thickness is 19.2mm. The front and back surfaces of the lens are coated with EDM UV 250-425nm, providing enhanced protection and performance in the specified UV range.
The lens's geometry includes a first radius of curvature (R1) of 23.80500085936053, a second radius of curvature (R2) of 0, and a back focal length (BFL) of 37mm. The lens's k1 is -0.773, and its na is 0.48. The front and back surfaces have an e of 2.068684e-06 and 9.79887e-10, respectively, and a g of 3.68327e-13 and 0, respectively. The h and l for both surfaces are 0.
This lens is a versatile and high-performing option for UV applications, offering superior image quality and protection in its class.