Before revision: In terms of OPL, the condition for to be a ray path (Fermat's principle) becomes This has the form of Maupertuis's principle in classical mechanics (for a single particle), with the ray index in optics taking the role of momentum or velocity in mechanics.Cf.
After revision: In terms of OPL, the condition for to be a ray path (Fermat's principle) becomes This has the form of Maupertuis's principle in classical (for a single particle), with the ray index in optics taking the role of momentum or velocity in mechanics.Cf.