Under "the second Bragg resonance" we'll mean such interaction conditions of light with volumetric (three-dimensional) periodic phase gratings when interaction takes place under dual Bragg angle and here the second and zeroth diffraction orders will be the most essential. If besides of the second and zeroth orders of diffraction there is the first order component, i.e. the three-wave diffraction condition is realized, then such a regime we'll call the intermediate one.