89-608 25mm Dia. Germanium Infrared Aspheric Lens; EFL=15mm; NA=0.83 BBAR 3-12µm

This is the 89-608 model from Edmund Optics, a 25mm diameter Germanium Aspheric Lens, specifically designed for infrared applications with a wavelength of 4000µm. The lens boasts an effective focal length (EFL) of 15mm and a numerical aperture (NA) of 0.83, making it a high-performance component in its class.

The lens is made from Germanium burnett, a material known for its excellent transmission properties in the infrared spectrum. The aspheric design of the lens helps to reduce spherical aberration, a common issue in traditional lenses, thereby improving the overall image quality.

The lens features a broadband anti-reflection (BBAR) coating, which is applied to both the front and back surfaces. This coating enhances the lens's performance by reducing surface reflections, thereby increasing the amount of light transmitted through the lens. The BBAR coating is designed to work across a wide range of wavelengths, from 3µm to 12µm, making this lens highly versatile.

The geometry of the lens includes an inner radius of 0mm, an outer radius of 0mm, a thickness at the edge of 2.47mm, and a thickness at the center of 4mm. The front and back focal lengths are -1.0785422e-05mm and 1.1954471e-08mm respectively, and the lens has a conic constant of 0. The lens's shape is aspheric, which contributes to its high performance.