67-635 15mm Dia. x 50mm FL; NIR II Coated; Double-Convex Lens NIR II 750-1550nm

The 67-635 is a high-quality double-convex lens, 15mm in diameter and 50mm in focal length, designed for use in the near-infrared (NIR) spectrum. This lens is sourced from Edmund Optics, a leading provider of optical components, and is part of their NIR-II series, which is specifically designed for use in the extended NIR range of 750-1550nm.

The lens is made from n-BK7 Schott, a popular optical glass due to its excellent optical properties and high Abbe number. This makes it an ideal choice for applications that require high image quality and low dispersion. The lens features a standard curve coating on both the front and back surfaces, specifically the EDM NIR-II std curve. This coating is designed to enhance the lens' performance in the NIR spectrum, reducing reflection and increasing transmission.

The geometry of the lens is carefully designed to provide optimal performance. The lens has a center thickness of 3mm and an edge thickness of 1.9mm, providing a robust and durable structure. The front and back radii of the lens are 51.16mm and -51.16mm respectively, creating a double-convex shape that focuses light effectively. The back focal length is 49mm, and the effective focal length is 50mm, providing a wide field of view and high light gathering capability.