The LB1869-C is a high-quality bi-convex lens offered by Thorlabs, a leading vendor in the optical industry. This lens, designed for use in the 1050-1700nm wavelength range, is made from N-BK7, a popular glass type known for its excellent optical properties.
The lens features a diameter of 1 inch (25.4mm) and a focal length of 500.0mm, making it suitable for a wide range of applications. The bi-convex shape, characterized by two convex surfaces, provides a high degree of focusing power. The lens has an effective focal length (EFL) of 200mm and a back focal length (BFL) of 499.2mm.
The LB1869-C is coated with Thorlab's anti-reflection coating, which is broadband and has a high transmission range. This coating, denoted as 'tho c bbar', is applied to both the front and back surfaces of the lens, reducing reflection and increasing transmission in the specified wavelength range.
The lens has a center thickness of 2.9mm and an edge thickness of 2mm, providing robustness and durability. The lens is spherical in shape, a common and versatile geometry in optical systems.