LE1202-B 25.4 mm Dia. N-BK7 Positive Meniscus Lens; EFL=200mm 650-1050nm

The LE1202-B is a 25.4 mm diameter Spherical Lens with a Positive Meniscus shape, sourced from the reputable optical components manufacturer, Thorlabs. This lens is designed for use within the wavelength range of 650-1050nm, making it suitable for a wide range of optical applications.

The lens features an effective focal length (EFL) of 200mm, which is a critical parameter in determining the lens's magnification power. The EFL is the distance from the lens's center to the point at which light rays converge or diverge, depending on the lens's design. In this case, the positive meniscus design indicates that the lens will cause light rays to converge, making it a converging lens.

The lens's geometry includes an edge thickness of 2mm and a center thickness of 2.8mm. The inner and outer radii are both 0, indicating that the lens's curved surfaces are parallel. The back focal length (BFL) is 196.5mm, which is the distance from the lens's rear surface to its focal point.

The LE1202-B lens is made from N-BK7, a high-quality borosilicate glass known for its excellent optical properties. This material is often used in high-precision optical systems due to its low dispersion and high transmission across a wide range of wavelengths.

The lens is coated with a broadband anti-reflection coating, denoted as 'tho b bbar' in the item data. This coating is applied to both the front and back surfaces of the lens and is designed to reduce reflection and increase transmission, thereby improving the lens's performance in high-power applications.