67-641 20mm Dia. x 25mm FL; NIR II Coated; Double-Convex Lens NIR II 750-1550nm

The 67-641 is a high-quality double-convex lens, designed and manufactured by Edmund Optics, a leading global provider of optical components. This lens boasts a 20mm diameter and a focal length of 25mm, making it suitable for a wide range of applications.

The lens is constructed from n-SF11 Schott, a high-index glass with excellent optical properties. This material is known for its low auto-fluorescence, making it ideal for use in near-infrared (NIR) applications. The lens features a double-convex geometry, with radii of curvature of 38.34mm and -38.34mm for the first and second surfaces, respectively. This geometry provides a high level of optical power and a compact form factor.

The 67-641 lens is coated with Edmund Optics' standard NIR-II coating on both the front and back surfaces. This coating is designed to optimize the lens' performance in the NIR spectrum, specifically in the 750-1550nm range. It provides high transmission and excellent environmental resistance, ensuring reliable performance in a variety of conditions.

The lens has a thickness of 1.35mm at the edge and 4mm at the center, providing a robust and durable design. The inner and outer radii are 0mm, indicating a circular shape. The effective focal length (EFL) of the lens is 25mm, and the back focal length (BFL) is 23.86mm.