Prism
Refracts through all three drawn boundaries with selectable catalogue-glass dispersion and traced path-length GDD.
Open in the canvas →In the real world
A prism disperses light because its refractive index depends on wavelength. Each face refracts according to Snell's law:
Since n itself varies with λ, different colors refract by different amounts and separate — this is why white light fans into a rainbow. Real optical glass is characterized by a Sellmeier equation, a sum of resonance terms fit to measured data, not a single simple formula.
In OpticalSetup
Each face is a genuine refracting boundary — incident rays bend by real vector Snell's law, and a ray that exceeds the critical angle undergoes total internal reflection instead of exiting, exactly as a real prism does. For dispersion, broadband and supercontinuum beams are sampled at several discrete wavelengths across their band, and each sample refracts with its own wavelength-dependent index, so the beam visibly fans into a spectrum. N-BK7, fused silica, N-SF5, and N-SF11 are selectable; existing sketches still default to N-BK7. Pulsed rays add GDD from their actual traced distance inside the selected glass.
The Sellmeier curves make refractive index and GDD accurate to a few percent over their valid transparent ranges, but absorption bands, temperature, coatings, and surface quality are not modeled; the fixed per-face transmission is the only loss.