Optical Engineering • Open AccessMomentum exchange theory of photon diffraction
Momentum exchange theory (MET) provides an alternative picture for optical diffraction based on a distribution of photon paths through momentum transfer probabilities determined at the scattering aperture. This is contrasted with classical optical wave theory that uses the Huygens–Fresnel principle and sums the phased contributions of wavelets at the point of detection. Single-slit, multiple-slit (Talbot effect), and straight-edge diffraction provide significant clues to the geometric parameters controlling momentum transfer probabilities and the relation to Fresnel zone numbers. Momentum transfer is primarily dependent on preferred momentum states at the aperture and the specific location and distance for momentum exchange. Diffraction by an opaque disc provides insight to negative (attractive) dispersions. MET should simplify the analysis of a broadened set of aperture configurations and experimental conditions.