Nonlinear optical diffraction by standing acoustic waves in a GaAs film

► We investigate nonlinear acousto-optical diffraction by standing acoustic waves in a GaAs crystalline film. ► We analyze second-harmonic nonlinear diffraction by longitudinal and transversal standing acoustic waves. ► Longitudinal standing acoustic waves only permit p-polarized nonlinear diffraction. ► Transversal standing acoustic waves allow all polarization combinations of incident and nonlinear diffracted light. ► Numerical calculations of nonlinear diffraction efficiencies are carried out. Second-order nonlinear optical diffraction by standing acoustic waves in a crystalline plate is theoretically investigated. A detailed analysis of the polarization state of the second-harmonic light diffracted by both longitudinal and transversal acoustic waves is carried out. It is shown that longitudinal standing acoustic waves only allow p-polarized nonlinear optical diffraction, irrespective of the incoming state of polarization, whereas transversal standing acoustic waves allow all possible combinations of incoming and diffracted polarization states. Numerical estimates of the relative intensities of nonlinearly diffracted radiation peaks are made for a GaAs plate.