| Abstract: | The transformation processes of holograph gratings in photorefractive crystals from two-wave interaction with detuning have been studied. For weak interactions an analytic solution has been obtained. Analysis of the gain, both for a purely nonlocal response, and for phase-shifted responses has been performed. Gain thresholds have been determined in terms of their dependence on materials parameters and the conditions of interaction. It is shown that the main effects in the gain process are a rotation of the grating vector towards its Bragg orientation and the appearance of a strong nonuniformity in the grating in proportion to the gain. As a result, for significant increases in the thresholds, the growth of the diffraction field of a non-Bragg-matched grating is larger than for diffraction of a Bragg-matched grating.Tomsk State Academy of Linear Systems and Radioelectronics. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 77–83, July, 1995. |
