The LA1951-B is a plano-convex lens from Thorlabs, designed with a spherical surface and a circular base shape. This lens is fabricated from N-BK7, a popular glass type from Schott, known for its excellent optical properties. The lens has a diameter of 1 inch (25.4 mm) and a thickness of 1.8 mm at the edge, while the center thickness measures 11.7 mm.
The lens' effective focal length (EFL) is 25.4 mm, and its radius of curvature (R1) is 13.1 mm. The back focal length (BFL) is 17.6 mm. The lens does not have an inner or outer radius.
The LA1951-B is coated with Thorlabs' BBAR coating (Broadband Anti-Reflection) on both the front and back surfaces, specifically designed for the ARC 650-1050nm range. This coating enhances the lens' performance by reducing surface reflections and increasing transmission.