Achromatic Doublet Designer
Design a cemented achromatic doublet from glass pair data. Computes individual element powers and focal lengths using the thin-lens achromatization condition.
An achromatic doublet is a two-element cemented lens designed to bring two wavelengths to the same focal point, eliminating primary chromatic aberration. The design uses a crown glass element (high Abbe number, low dispersion) and a flint glass element (low Abbe number, high dispersion) with powers chosen so their chromatic aberrations cancel. This calculator applies the thin-lens achromatization condition (φ₁/V₁ + φ₂/V₂ = 0 with φ₁ + φ₂ = φ_total) to compute each element's focal length from the target system focal length and the Abbe numbers of the selected glass pair. Use this tool when designing a custom doublet, comparing glass pairs, or verifying a supplier's achromat specification.