Abstract

Quasi-phase-matching (QPM) offers a very attractive approach to produce highly-efficient parametric wave-mixing interactions in quadratic nonlinear optical media.¹ Conventional phase-matching techniques used to compensate for the phase-velocity mismatch between the waves of difference frequencies that interact in the nonlinear medium are based on the birefringence and thermal properties of the materials involved. Hence, the overall efficiency of the interaction is limited by a variety of effects, mainly Poynting vector spatial beam walk-off due to the different propagation directions of energy and phase fronts in anisotropic media, non-convenient operation temperatures and crystalline optical axes orientations, and the value of the second-order nonlinear coefficients accessible through the polarization of the waves involved in the parametric interaction.

© 1996 Optical Society of America