Sheng Yan, Saltiel Solomon M, Koynov Kaloian
Max Planck Institute for Polymer Research, Mainz, Germany.
Opt Lett. 2009 Mar 1;34(5):656-8. doi: 10.1364/ol.34.000656.
Collinear third-harmonic generation at 526.7 nm was realized by the simultaneous phase matching of two second-order processes in a single quadratic crystal: second-harmonic generation (SHG) and sum-frequency mixing (SFM). The measured conversion efficiency was 12%. As a nonlinear medium a LiNbO(3) nonlinear photonic crystal with short-range order was used that allowed simultaneous phase matching by use of discrete reciprocal vector (for the SHG process) and continuous reciprocal vectors (for the SFM process). It was demonstrated that the third harmonic could be generated efficiently in such a crystal even if the intermediate process of SHG was not perfectly phase matched.
通过在单个二次晶体中同时实现两个二阶过程的相位匹配，即二次谐波产生（SHG）和和频混合（SFM），实现了526.7nm的共线三次谐波产生。测得的转换效率为12%。使用了具有短程有序的LiNbO(3)非线性光子晶体作为非线性介质，该晶体通过使用离散倒易矢量（用于SHG过程）和连续倒易矢量（用于SFM过程）实现了同时相位匹配。结果表明，即使SHG的中间过程没有完美相位匹配，在这种晶体中也能高效产生三次谐波。
