Abstract
Intensity distribution of the light diffraction spectrum produced by progressive ultrasound is calculated by the normal mode theory-extended Brillouin theory-over a wide range of the parameters pertaining to this phenomenon and under condition of the normal incidence and under Bragg incidences of various orders. It is found that both “Bragg maxima” and “Bragg minima” take place for various order spectra according to the ranges of the various parameters pertaining to this phenomenon. The intuitive mechanism for the variation of the spectrum outside of the Raman-Nath region and the true Bragg region is attributable to the mirror-type Bragg reflection anticipated by th eray-optics theory.
