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A general approach to the space–charge field solution in photorefractive materials in a TWM geometry

A general approach to the approximate analytical solution of photorefractive transport equations for arbitrary fringe contrast is presented. The method based partially on the perturbative scheme permits us to find the stationary space–charge field distribution inside a photorefractive crystal for a two-wave mixing (TWM) geometry with a DC electric field. The method can be employed for various band transport models. In the present work two distinct electron–hole conduction models are investigated. The solutions are compared with the results of numerical calculations and good agreement is found.