49-308 6.25 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=30mm VIS-NIR 400-1000nm

The 49-308 is a high-quality achromatic doublet lens, boasting a 6.25 mm diameter and a focal length of 30mm, specifically designed for the visible to near-infrared spectrum (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 materials, N-BK7 and N-SF5, both from Schott, ensuring superior optical performance. The N-BK7, a borosilicate crown glass, is known for its low dispersion and excellent homogeneity, while the N-SF5, a fluorite crown glass, offers a high Abbe number and low refractive index. This combination effectively minimizes chromatic aberration, a common issue in lens systems.

The lens geometry is meticulously designed, with an inner radius of 0 and an outer radius of 0, indicating a symmetrical structure. The edge thickness is 2.8mm, while the center thickness is 2.3mm, providing robustness and stability. The lens also features a front and back coating of edm visnir0sp2002000, which enhances its transmission and durability in the specified wavelength range.

This lens is a multiplet, meaning it is composed of multiple elements, which is advantageous for achromatic applications. The radii of curvature for the three surfaces are r1=18.11mm, r2=-13.51mm, and r3=-39.29mm, contributing to the lens's excellent optical performance.