The SLB-20B-30NM is a high-quality double-concave lens, designed and manufactured by OptoSigma. This lens, with a base shape of a circle, is specifically engineered for use within the wavelength range of 400-700nm, making it suitable for a wide range of optical applications.
The lens boasts a diameter of 20.0 mm, with a thickness at the edge of 5.3 mm and a center thickness of 2.0 mm. The effective focal length (EFL) is -29.7 mm, and the back focal length (BFL) is -30.3 mm. The first radius of curvature (R1) is -31.14 mm, while the second radius of curvature (R2) is 31.14 mm. The inner and outer radii are both 0 mm.
The lens is made from n-BK7 Schott, a popular optical glass due to its excellent optical properties and relatively low cost. The lens is coated with Opt M on both the front and back, enhancing its performance and durability.
The item data indicates that this lens is in stock and available for immediate purchase. For more information, including pricing and detailed specifications, please refer to the provided web link.