47-656-INK 9 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=40mm VIS 0° 425-675nm

The 47-656-INK is a high-quality achromatic doublet lens, boasting a 9 mm diameter and an effective focal length (EFL) of 40 mm, specifically designed for the visible light spectrum ranging from 425 to 675 nm. This lens is sourced from the renowned optical components manufacturer, Edmund Optics, and is available for purchase through their official website.

This achromatic doublet is a compound lens made from two different types of glass, N-BK7 and N-SF5, which are both manufactured by Schott. The use of these materials helps to minimize chromatic aberration, a common issue in optical systems where different wavelengths of light are focused at different points. By correcting this aberration, the 47-656-INK provides clear, sharp images across the entire visible light spectrum.

The lens features a standard curvature coating on both the front and back surfaces, denoted as 'edm vis-0 std curve'. This coating is designed to enhance the lens's performance in the visible light spectrum, further improving image quality.

The geometry of the lens includes a thickness of 4.45 mm at the edge, a center thickness of 3.73 mm, and a central thickness 'a' of 1.33 mm. The lens's inner and outer radii are both zero, and it has a base shape of a circle. The radii of curvature for the first and second surfaces are 24.77 mm and -18.01 mm, respectively, while the third surface has a radius of -51.17 mm.