title: Perfect quasi-phase matching for the third-harmonic generation using focused Gaussian beams.
abstract: We propose a method to realize perfect quasi-phase matching (QPM) for nonlinear optical interactions involving Gaussian beams. Using this method, both the wave-vector mismatching and the Gouy phase shift can be compensated. Numerical simulations for the third-harmonic generation show that conversion efficiency near to 100% can be realized even if the fundamental wave is tightly focused, which is difficult or even impossible with the conventional QPM method.
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Yi-Qiang
authors.initials: YQ
authors.lastname: Qin
authors.forename: Yong-Yuan
authors.initials: YY
authors.lastname: Zhu