This is the 87-998 model from Edmund Optics, a 50mm diameter Germanium Aspheric Lens designed for infrared applications with a wavelength of 4000nm. The lens is coated with BBAR (Broadband Anti-Reflection) coating for both the front and back surfaces, ensuring optimal performance in the 8-12µm spectral range.
The lens features a focal length (EFL) of 50mm, providing a wide field of view for various imaging and detection applications. The lens has a numerical aperture (NA) of 0.5, which is a measure of the light-gathering ability of the lens. A higher NA allows for a greater resolution and a wider field of view.
The lens geometry includes an inner radius of 0mm, an outer radius of 0mm, a thickness at the edge of 2.52mm, and a thickness at the center of 5.1mm. The front and back surfaces of the lens have radii of curvature of 46.88mm and 62.38mm, respectively. The lens also features aspheric surfaces, which help to reduce spherical aberration and improve image quality.
The lens is available for purchase through the Edmund Optics website, and as of the time of data collection, it is in stock. The link to the product page is provided in the item data for your convenience.