The LB1917-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 2 inches and a focal length of 300.0 mm.
The lens is spherical in shape, with a front radius of curvature (R1) of 308.2 and a back radius of curvature (R2) of -308.2. This bi-convex design allows for efficient light collection and focusing, making it ideal for use in imaging systems, beam shaping, and other applications where precise light control is required.
The LB1917-B is coated with Thorlabs' BBAR coating on both the front and back surfaces, which reduces reflection and increases transmission in the 650-1050nm wavelength range. This coating enhances the lens' performance in near-infrared applications, such as laser systems and spectroscopy.
The lens has a thickness of 3mm at the edge and 5.1mm at the center, providing robustness and durability. It is available for purchase directly from Thorlabs, and the company's website indicates that it is currently in stock.