39-517 25.4mm Dia. ZnSe Aspheric Lens; EFL=50.8mm; NA=0.25 BBAR 8-12µm

This is a high-quality 39-517 aspheric lens, sourced from the renowned optical vendor, Edmund Optics. The lens boasts a 25.4mm diameter and is designed for use with a wavelength of 10600nm. It is crafted from ZnSe (Zinc Selenide) material, which is known for its excellent transmission properties in the infrared spectrum.

The lens features a focal length of 50.8mm (EFL), providing a narrower field of view and increased magnification compared to shorter focal length lenses. The numerical aperture (NA) is 0.25, which indicates the light-gathering capability of the lens. A higher NA allows for a shallower depth of field and higher resolution, making this lens suitable for applications that require a high level of detail.

The lens is coated with BBAR (Broadband Anti-Reflection) coating, specifically designed for the 8-12µm range. This coating reduces surface reflections, thereby increasing the amount of light transmitted through the lens. The BBAR coating also helps to minimize ghosting and flaring, which can degrade image quality.

The geometry of the lens is defined by its inner and outer radii, which are both 0 in this case. The lens has a thickness of 2.38mm at the edge and 3.5mm at the center. The front and back surfaces of the lens are aspheric, meaning they are not spherical but rather shaped to reduce spherical aberration and improve optical performance.