68-248 25mm Dia. Germanium Infrared Aspheric Lens; EFL=40mm; NA=0.31 BBAR 3-5µm

This is a high-quality 25mm diameter germanium aspheric lens, catalog number 68-248, available from the renowned optical components vendor, Edmund Optics. The lens is specifically designed for infrared applications, with a focal length of 40mm and a numerical aperture of 0.31.

The lens is made from germanium burnett, a material known for its excellent transmission properties in the infrared spectrum. It features a broadband anti-reflection coating (BBAR) that enhances its performance by reducing surface reflections, thereby improving transmission and image quality. The coating is effective across the 3-5µm wavelength range, making it suitable for a wide range of infrared applications.

The lens geometry is meticulously designed with an inner radius of 0 and an outer radius of 0, ensuring optimal light transmission and minimal distortion. The lens has a thickness of 2.38mm at the edge and 3.1mm at the center, providing robustness and stability. The front and back surfaces of the lens are aspheric, which helps to correct spherical aberration and improve optical performance.

The lens is supplied with detailed geometry information, including radii (r1 and r2), back focal length (bfl), and various other parameters. This data can be used to accurately model the lens in optical design software, enabling users to predict its performance in their specific application.