The LB1889-C is a high-quality bi-convex lens from Thorlabs, designed for use in a wide range of optical applications. This lens is fabricated from N-BK7 Schott glass, a popular material known for its excellent optical properties and versatility.
The lens features a diameter of 2 inches (50.8 mm) and a focal length of 250.0 mm, providing a beam divergence that is suitable for many applications. The lens has a double-convex shape, with radii of curvature of 256.6 mm for the first surface and -256.6 mm for the second surface. This shape allows for efficient light collection and focusing.
The LB1889-C is coated with Thorlabs' Broadband Anti-Reflection Coating (BBAR), which is designed to reduce surface reflections and increase transmission across the 1050-1700nm wavelength range. This coating ensures optimal performance in near-infrared applications.
The lens has a central thickness of 9.5 mm and an edge thickness of 3 mm, providing robustness and durability. The lens is also available with custom AR coatings upon request, allowing for tailored performance in specific applications.