22-997 15mm Dia. N-BK7 Precision Aspheric Lens; EFL=22.5mm; NA=0.33 SWIR-Plus 900-1700nm

This is the 22-997 model from Edmund Optics, a high-precision asperic lens designed for use in the shortwave infrared (SWIR) region, specifically between 900 and 1700 nanometers. The lens is made from N-BK7, a popular glass type known for its excellent optical properties, including a high refractive index and low dispersion.

The lens has a diameter of 15mm and a numerical aperture (NA) of 0.33, which is a measure of the light-gathering ability of the lens. The effective focal length (EFL) of this lens is 22.5mm, which is the distance over which the lens focuses light. The lens also features a high-quality anti-reflection coating, denoted as "edm swirplus90017003", on both the front and back surfaces to minimize losses due to reflection.

The asphere of the lens is defined by its inner and outer radii, thicknesses at the edge and center, and the conic constant (k1). The inner radius is 0, the outer radius is also 0, the thickness at the edge is 6.25mm, and the thickness at the center is 8.79mm. The conic constant (k1) is -0.901164, which determines the shape of the asphere.

This lens is a great choice for applications that require high-quality imaging in the SWIR region, such as night vision, thermal imaging, and scientific research. It is currently in stock, according to the vendor's website, and more information can be found at the provided weblink.