The LB1859-B is a high-quality bi-convex lens manufactured by Thorlabs, a leading global supplier of photonics equipment. This lens is designed for use in the 650-1050nm wavelength range, making it suitable for a wide range of applications in the fields of optics and photonics.
The lens is made from N-BK7, a popular optical glass due to its excellent optical properties. It has a diameter of 2 inches (50.8mm) and a thickness of 3mm at the edge, while the center thickness is slightly higher at 3.6mm. The effective focal length (EFL) of the lens is 1000mm, and the back focal length (BFL) is 998.8mm.
The LB1859-B features a spherical geometry with radii of curvature of 1029.5mm for both the front and back surfaces. The inner and outer radii are zero, indicating a uniform curvature across the lens surface.
The lens is coated with Thorlabs' BBAR coating on both the front and back surfaces. This anti-reflection coating is designed to reduce surface reflections and increase transmission in the 650-1050nm wavelength range.