49-381 40 mm Dia. N-SSK8/N-SF10 Achromatic Doublet; EFL=120mm VIS-NIR 400-1000nm

The 49-381 is a high-quality achromatic doublet lens, sourced from the renowned optical vendor, Edmund Optics. This lens is specifically designed for use in the visible (VIS) and near-infrared (NIR) spectrum, spanning 400-1000nm. The lens boasts a 40mm diameter and an effective focal length (EFL) of 120mm, making it suitable for a wide range of optical applications.

The lens is composed of two elements, each made from different materials: N-SSK8 and N-SF10, both from Schott. This combination helps to correct chromatic aberration, a common issue in optical systems where different wavelengths of light are focused at different points. The achromatic design ensures that the lens focuses both red and blue light at the same point, providing sharper images and improved color accuracy.

The lens features a complex geometry, with three radii of curvature (r1, r2, and r3) and varying thicknesses at the edge, center, and a specific point (thickness edge, thickness center, and thickness center a). This geometry allows for precise control over the lens's optical properties, enabling it to deliver superior performance.

The lens is coated with Edmund Optics' VIS-NIR coating (edm visnir0sp2002000) on both the front and back surfaces. This coating is designed to enhance the lens's transmission in the VIS and NIR ranges, reducing reflections and improving overall light efficiency.