The influence of quadratic recombination is analyzed theoretically and numerically by formal derivation of the material wave equation including this effect. Analytically, it is shown how the quadratic recombination alters the nonlinear properties of space-charge waves. The influence of higher-harmonic components induces both a nonlinear frequency shift and a nonlinear shift in dissipation. Numerically, it is shown that 12 higher-harmonic components are necessary to cover the entire region of intensity contrast and that the quadratic recombination effect gives significant corrections for small frequencies below the fundamental resonance frequency.
© 1999 Optical Society of America
(090.7330) Holography : Volume gratings
(160.5320) Materials : Photorefractive materials
(190.4410) Nonlinear optics : Nonlinear optics, parametric processes
(190.5330) Nonlinear optics : Photorefractive optics
Per Michael Johansen, Henrik C. Pedersen, and Evgeny V. Podivilov, "Influence of quadratic recombination on grating recording in photorefractive crystals," J. Opt. Soc. Am. B 16, 1120-1126 (1999)