67-251 20 mm Dia. N-SF5 Precision Aspheric Lens; EFL=12.5mm; NA=0.8 BBAR 425-675nm

The 67-251 is a high-precision aspheric lens offered by Edmund Optics. This lens, with a catalog number 67-251, is designed for use in the visible spectrum, specifically at a wavelength of 587.6 nm. It is made from N-SF5 Schott, a high-refractive index glass that is often used in optical applications requiring high numerical aperture (NA) and excellent optical performance.

The lens features a 20 mm diameter and a numerical aperture (NA) of 0.8, indicating a high light-gathering capability. The aspheric design of the lens helps to reduce spherical aberration, a common issue in traditional spherical lenses, thereby improving the image quality. The lens has an effective focal length (EFL) of 12.5 mm, which is the distance from the lens's principal point to the focal point when the lens is focused at infinity.

The lens is coated with BBAR (Broadband Anti-Reflection) coating, which is designed to reduce reflection and increase transmission over a broad spectrum (425-675 nm). This coating enhances the lens's performance in a wide range of applications, including imaging, beam shaping, and laser applications.

The lens has a center thickness of 9 mm and an edge thickness of 1.91 mm. The front and back surfaces of the lens are coated with the same BBAR coating. The lens is available for purchase through the Edmund Optics website, and as of the time of data collection, it is in stock.