Acousto-Optic Tunable Quasi-Phase-Matching Nonlinear Effects in Periodically Poled LiNbO3

We proposed the coupling and competition of second harmonic generation (SHG) and acousto-optic (AO) interaction in periodically poled lithium niobate (PPLN). The reciprocal vector of PPLN compensates the SHG wave-vector mismatch when quasi-phase-matching (QPM) condition is satisfied, while phonons with suitable frequencies may affect it by scattering photons to different polarization state. Second harmonic waves´ intensities, polarization states and even phases thus could be manipulated instantly through AO interaction.