LF1544-A 25.4 mm Dia. N-BK7 Negative Meniscus Lens; EFL=-400mm 350-700nm

The LF1544-A is a high-quality spherical lens from Thorlabs, featuring a negative meniscus design with a diameter of 25.4 mm. This lens is specifically designed for use in the ultraviolet, visible, and near-infrared regions of the spectrum, spanning from 350 to 700 nm.

The lens is made from N-BK7, a popular borosilicate glass known for its excellent optical properties. This material is characterized by a low coefficient of thermal expansion, making it resistant to thermal shock. The lens has a center thickness of 3 mm and an edge thickness of 3.4 mm, providing a robust structure that can withstand typical handling and usage.

The LF1544-A has a focal length (EFL) of -400 mm, indicating that it is a diverging lens. This is further confirmed by its radii of curvature, with r1 at 250 mm and r2 at 112.5 mm. The back focal length (BFL) is -397 mm, and the lens has no inner or outer radius, indicating a simple meniscus design.

The lens is coated with Thorlabs' anti-reflection coating, denoted as THo A Bbar. This coating is designed to reduce surface reflections and increase transmission, ensuring optimal performance in a wide range of applications.