68-249 25mm Dia. Germanium Infrared Aspheric Lens; EFL=50mm; NA=0.25 BBAR 3-5µm

This is a high-quality aspheric lens from Edmund Optics, specifically designed for infrared applications with a wavelength of 4000nm. The lens, cataloged under the number 68-249, has a base shape of a circle and is made of germanium burnett material, ensuring excellent performance in the infrared spectrum.

The lens has a diameter of 25mm and an effective focal length (EFL) of 50mm, making it suitable for a wide range of applications. The lens features a high numerical aperture (NA) of 0.25, which allows for a wide angle of view and increased light gathering capability. The aspheric design of the lens helps to reduce spherical aberration, providing sharper images and improved performance.

The lens is coated with BBAR 3-5µm, which stands for Broadband Anti-Reflection coating for 3 to 5µm wavelengths. This coating helps to reduce surface reflections, improving transmission and enhancing the overall performance of the lens.

The lens has a thickness of 2.45mm at the edge and 3mm at the center. The inner and outer radii are not specified, indicating that they are not critical to the lens's performance. The front and back of the lens are coated with the same coating, ensuring optimal performance from both sides.

The lens is currently in stock and can be purchased directly from the Edmund Optics website using the provided weblink.