45-137 12.5 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=60mm MgF2 400-700nm

The 45-137 is a high-quality achromatic doublet lens from Edmund Optics, designed with a 12.5 mm diameter and a focal length of 60mm. This lens is a multiplet, meaning it is composed of multiple optical elements to achieve superior performance.

The lens is constructed from two types of glass: N-BK7 and N-SF5, both from Schott. N-BK7, also known as BK7, is a borosilicate crown glass known for its excellent optical properties and high transmittance in the visible spectrum. N-SF5, on the other hand, is a dense flint glass with high refractive index and dispersion, making it ideal for achromatic applications.

The lens features a standard MgF2 coating on both the front and back surfaces. This coating reduces reflection and increases transmission in the 400-700nm range, enhancing the lens's overall performance and making it suitable for a wide range of applications.

The geometry of the lens includes a thickness of 4.21mm at the edge, a center thickness of 3.5mm, and a central thickness 'a' of 1.5mm. The lens's inner and outer radii are 0, indicating a circular shape. The radii of curvature are 36.51mm for the first surface, -26.33mm for the second surface, and -78.35mm for the third surface.

This lens is currently in stock and available for purchase through the Edmund Optics website. With its superior optical properties and robust construction, the 45-137 is an excellent choice for a wide range of optical applications.