Gated recording based on two-step excitation with metastable shallow traps is analyzed theoretically. A two-center model, including the tail of the conduction band into the bandgap, is suggested. The tail provides a way to model efficiently excitation from deep to shallow traps and long recombination times back into deep traps. The results are compared with experimental results performed with La<sub>3</sub>Ga<sub>5</sub>SiO<sub>14</sub>, and good agreement is found. Further, the limiting material parameters determining the material sensitivity are identified.
© 2001 Optical Society of America
Thomas Nikolajsen, Per Michael Johansen, Boris I. Sturman, and Evgeni V. Podivilov, "Modeling of photorefractive two-step gated recording by long-life-time intermediate levels," J. Opt. Soc. Am. B 18, 485-491 (2001)