AC254-100-A 25.4 mm Dia. N-BK7/SF5 Unmounted Achromatic Doublet; EFL=100.1mm 400-700nm

The AC254-100-A is a high-quality achromatic doublet lens, sourced from the renowned optical component manufacturer, Thorlabs. This lens, with a diameter of 25.4 mm, is designed for use in the visible spectrum, specifically between 400-700nm.

The lens is a multiplet, meaning it is composed of multiple optical elements. The primary materials used in its construction are n-BK7 and SF5, both renowned for their optical properties. The n-BK7, a crown glass, is known for its low dispersion and high homogeneity, while the SF5, a flint glass, is used for its high dispersion. This combination helps to correct chromatic aberration, a common issue in optical systems.

The lens has a focal length of 100.1mm, indicated by the EFL (Effective Focal Length) parameter. This length is measured from the center of the lens to the point where the light rays converge. The lens's geometry includes an edge thickness of 4.7mm, and it features three radii of curvature (r1, r2, r3) that shape the lens's surface. The lens also has two central thicknesses (thickness center 1 and thickness center 2) that contribute to its overall optical performance.

The lens is coated with THo AC400-700-A, a broadband anti-reflection coating designed for use in the 400-700nm range. This coating reduces surface reflections, thereby increasing the amount of light transmitted through the lens.