This is a high-precision aspheric lens, catalog number 16-998, offered by Edmund Optics. It is designed for use in the shortwave infrared (SWIR) spectrum, specifically between 900 and 1700 nanometers. The lens is made from N-BK7, a popular glass type known for its excellent optical properties.
The lens has a diameter of 25mm and a numerical aperture (NA) of 0.33, making it suitable for a wide range of applications. The effective focal length (EFL) is 37.5mm, which is a common value for this type of lens. The lens is coated with Edmund Optics' SWIR-Plus coating, which is specifically designed for use in the SWIR spectrum.
The lens geometry is also noteworthy. It has an inner radius of 0mm, an outer radius of 0mm, and a thickness at the edge of 5.49mm. The thickness at the center is 9.72mm, and the lens has a front diameter of 0mm. The aspheric surface is defined by a conic constant of -0.6698934 and a quadratic term of 0.
The coating on both the front and back of the lens is Edmund Optics' SWIR-Plus coating, which provides high transmission in the SWIR spectrum. This coating is designed to enhance the performance of the lens in its intended application range.