The LB1904-B N-BK7 Bi-Convex Lens is a high-quality optical component sourced from Thorlabs, a leading vendor in the field of precision photonics. This lens, with a diameter of 1 inch, is designed for use in the wavelength range of 650-1050nm, making it suitable for a wide range of applications in the near-infrared spectrum.
The lens features a bi-convex geometry, meaning it has two spherical surfaces that are both convex, or curved outward. This design is often used to achieve a specific focal length, which in this case is 125mm. The lens's effective focal length (EFL) is 123.9mm, a slight deviation from the stated focal length due to the lens's thickness.
The lens is made from N-BK7, a type of borosilicate glass known for its excellent optical properties. This material is often used in high-precision optical systems due to its low coefficient of thermal expansion and high homogeneity. The lens's front and back surfaces are coated with a broadband anti-reflection coating (ARC), specifically designed for the 650-1050nm range. This coating reduces surface reflections, thereby increasing the amount of light transmitted through the lens.
The lens's geometry includes a diameter of 25.4mm, with a center thickness of 3.3mm and an edge thickness of 2mm. The inner and outer radii are not specified, indicating that they are not a significant factor in the lens's performance or application.