The 67-640 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 20mm focal length, making it suitable for a wide range of applications.
The lens is constructed from n-SF11 Schott, a highly transparent glass with excellent optical properties. This material is particularly suited for use in the near-infrared (NIR) spectrum, with a wavelength of 587.6nm. The lens is coated with Edmund Optics' NIR-II standard curve coating on both the front and back surfaces, enhancing its performance in the NIR range of 750-1550nm.
The geometry of the lens is carefully designed to optimize its optical performance. The lens has a center thickness of 5mm and an edge thickness of 1.6mm, providing a balance between weight and durability. The front and back radii of the lens are 30.25mm and -30.25mm respectively, creating a double-convex shape that focuses light effectively. The back focal length is 18.55mm, and the effective focal length is 20mm.