LB1391-B N-BK7 Bi-Convex Lens; Dia:1 in; f=400.0 mm ARC 650-1050nm

The LB1391-B is a high-quality bi-convex lens from Thorlabs, designed for use in a wide range of optical applications. This lens is made from N-BK7, a popular glass type known for its excellent optical properties, and features a diameter of 1 inch and a focal length of 400.0 mm.

The lens has a double-convex geometry, meaning it has two spherical surfaces that curve outwards. This design allows for a high degree of focusing power, making it ideal for use in imaging systems, beam shaping, and other applications where precise focusing is required. The lens has a center thickness of 2.4 mm and an edge thickness of 2 mm, providing a robust and durable construction.

The LB1391-B is coated with Thorlabs' BBAR coating, which stands for Broadband Anti-Reflection. This coating is designed to reduce surface reflections and increase transmission over a broad spectrum, specifically from 650 to 1050 nm. This makes the lens suitable for use with a wide range of light sources, including lasers and broadband light sources.

The lens is also AR-coated on both sides, ensuring minimal reflection and maximum transmission. This is particularly beneficial in applications where high light levels are required, such as in laser systems or high-power illumination applications.