49-347 18 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=125mm VIS-NIR 400-1000nm

The 49-347 is a high-quality achromatic doublet lens, boasting an 18 mm diameter and a focal length of 125mm, specifically designed for the visual (VIS) and near-infrared (NIR) spectrum, spanning 400-1000nm. This lens is sourced from the renowned optical vendor, Edmund Optics, and is available for immediate use.

The lens is constructed from two types of Schott glass, N-BK7 and N-SF5, which are renowned for their excellent optical properties. The N-BK7, a borosilicate crown glass, is known for its low dispersion and high homogeneity, making it ideal for use in achromatic doublets. The N-SF5, a dense flint glass, complements the N-BK7 by correcting chromatic aberration, ensuring sharp and clear images across the entire spectral range.

The lens features a sophisticated geometry, with a central thickness of 4.5mm and edge thickness of 5.72mm. The first and second radii of curvature are 76.92mm and -55.48mm, respectively, while the third radius of curvature is -162.59mm. This complex geometry is designed to minimize optical aberrations and distortions, further enhancing the lens's performance.

The lens is coated with Edmund Optics' VIS-NIR coating (edm visnir0sp2002000) on both the front and back surfaces. This coating is specifically designed to enhance the lens's performance in the VIS-NIR spectrum, reducing reflection and increasing transmission.