Prism Optics API

Optical-prism geometry as an API, computed locally and deterministically. The deviation endpoint computes the minimum deviation angle of a light ray passing through a prism of apex angle A and refractive index n, δ_min = 2·arcsin(n·sin(A/2)) − A, together with the symmetric angle of incidence and the internal refraction angle A/2 on each face — an equilateral prism (A = 60°) of crown glass (n = 1.5) deviates light by about 37.2°. The refractive-index endpoint inverts the spectrometer formula n = sin((A + δ_min)/2) / sin(A/2), the standard way a refractive index is measured from a prism’s apex angle and its measured minimum deviation. The dispersion endpoint computes the angular dispersion between two wavelengths from their refractive indices and the apex angle, and, given the three Fraunhofer indices n_F, n_C and n_D, the dispersive power ω = (n_F − n_C)/(n_D − 1) and the Abbe number V = 1/ω that quantify how strongly a glass spreads colours — crown glass has ω ≈ 0.017 and V ≈ 59. All angles are in degrees. Everything is computed locally and deterministically, so it is instant and private. Ideal for optics, spectroscopy, refractometry, photonics and physics-education app developers, lens-and-prism design tools, and lab software. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is prism geometry; for a single flat-surface refraction use a Snell’s-law API and for thin lenses a lens API.