General Solution Of Multifrequency Acousto-Optic Diffraction In Bragg Cells

A general method for calculating the scattering amplitude of multifrequency acousto-optic diffraction is established. The method is based on counting allowable Feynman diagrams. It is found that the ratio of the number of Feynman diagrams allowable in the Bragg regime (isotropic, birefringent, and degenerate) to that in the Raman-Nath regime is independent of the total number of different acoustic frequencies, being a function only of the order of the Feynman diagram and the diffraction order of the final state. A general expression for this ratio is obtained. With this as a basis, complete perturbation solutions of the scattering amplitude can be obtained for any final state, any number of acoustic frequencies, and any kind of multifrequency acousto-optic diffraction. The theory is verified by comparing with theoretical results obtained previously and with experiment results.