Anomalous diffraction theory

Anomalous diffraction theory is a concept in the field of wave optics and scattering theory, primarily applicable to the interaction of electromagnetic waves, such as light, with small particles. The term "anomalous" refers to the deviations from the standard diffraction patterns predicted by classical diffraction theory (e.g., Rayleigh diffraction) when the size of the scattering objects is comparable to the wavelength of the incident light.