Wave-front engineering for nonlinear optical interactions was discussed. Using Huygens-
Fresnel principle we developed a general theory and technique for domain engineering with
conventional quasi-phase-matching (QPM) structures being the special cases. We put
forward the concept of local QPM, which suggests that the QPM is fulfilled only locally not
globally. Experiments agreed well with the theoretical prediction. The proposed scheme
integrates three optical functions: generating, focusing, and beam splitting of second …

The wave-front engineering for nonlinear optical interactions was discussed. Using Huygens-
Fresnel principle we developed a general theory and technique for domain engineering with
conventional quasi-phase-matching (QPM) structures being the special cases. We put
forward the concept of local QPM, which suggests that the QPM is fulfilled only locally not
globally. Experiments agreed well with the theoretical prediction. The proposed scheme
integrates three optical functions: generating, focusing and beam splitting of second …