SLB-15B-50N 15.0 mm Dia. x -49.7 mm FL; Double-Concave Lens Uncoated

The SLB-15B-50N is a high-quality spherical lens offered by OptoSigma, a renowned vendor in the optical industry. This specific lens is a double-concave design, meaning it has two concave surfaces that curve inward. The lens is made from the material n-BK7 Schott, a popular choice due to its excellent optical properties and high damage threshold.

The lens has a diameter of 15.0 mm and a center thickness of 2.0 mm, with an edge thickness of 3.1 mm. The effective focal length (EFL) is -49.7 mm, indicating that it is a diverging lens, causing parallel light rays to spread out. The first radius of curvature (R1) is -51.9 mm, and the second radius of curvature (R2) is 51.9 mm, which are the radii of the curvature of the two surfaces of the lens. The back focal length (BFL) is -50.3 mm.

This lens is uncoated, meaning it does not have any anti-reflective coatings. While coatings can enhance the performance of a lens by reducing reflections and increasing transmission, uncoated lenses can be advantageous in certain applications where cost, simplicity, or specific optical characteristics are important.

The lens is designed to work at a wavelength of 546.1 nm, which is in the visible light spectrum. It is important to note that the performance of the lens can vary depending on the wavelength of the light it is used with.