47-659 9 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=75mm VIS 0° 425-675nm

The 47-659 is a high-quality achromatic doublet lens, sourced from Edmund Optics, featuring a 9 mm diameter and an effective focal length (EFL) of 75mm. This lens is specifically designed for the visible spectrum, covering wavelengths from 425 to 675nm.

The lens is constructed from two types of glass, N-BK7 and N-SF5, both from Schott, ensuring excellent optical performance. The N-BK7, a borosilicate crown glass, is known for its low dispersion and high transmission in the visible spectrum. The N-SF5, a dense flint glass, further reduces chromatic aberration, contributing to the lens's achromatic properties.

The lens's geometry is meticulously designed, with a central thickness of 3mm and edge thickness of 4.28mm. The radii of curvature are R1 = 46.44mm, R2 = -33.77mm, and R3 = -95.94mm, providing the lens with its unique optical properties. The lens also features a standard anti-reflective coating on both the front and back surfaces, optimized for the visible spectrum (VIS 0°), further enhancing its performance.

This lens is a multiplet, meaning it is composed of multiple elements, which is advantageous for applications requiring high image quality, low distortion, and minimal chromatic aberration. The 47-659 is a versatile lens, suitable for various applications, including imaging, beam shaping, and laser systems.