The 31-861 is a high-quality double-convex lens, sourced from the renowned optical vendor, Edmund Optics. This lens, with a 6mm diameter and a focal length of 9mm, is designed for use within the wavelength range of 400-700nm, making it suitable for a wide range of optical applications.
The lens is constructed from n-BK7 Schott, a popular optical glass due to its excellent optical properties and versatility. The base shape of the lens is circular, and it features a standard spherical geometry. The center thickness of the lens is 2.25mm, while the edge thickness is 1.22mm, providing a robust structure for efficient light transmission.
The 31-861 lens is coated with EDM MgF2 std curve on both the front and back surfaces. This coating enhances the lens's performance by reducing reflection and increasing transmission, thereby improving the overall efficiency and quality of the optical system.
The lens's geometry includes an inner radius of 0mm and an outer radius of 0mm, indicating a symmetrical design. The effective focal length (EFL) is 9mm, and the back focal length (BFL) is 8.22mm. The first radius of curvature (R1) is 8.91mm, and the second radius of curvature (R2) is -8.91mm.