非线性左手材料中的二次谐波

基于电磁场理论，推导了无耗非线性左手材料中二次谐波的曼利－诺关系，及相位匹配条件下正向基波与逆向二次谐波的能量转换过程及其空间分布.验证了可将无耗非线性左手材料的入射面作为反射镜，把能量以二次谐波的形式反射.同时分别给出有限厚度介质板中基波和二次谐波的场强分布数值结果，验证了结论的正确性.最后从相位失配角度说明了相位匹配是分析非线性左手材料二次谐波的重要条件.这为研究左手材料的非线性理论奠定了基础.

Second-harmonic generation in nonlinear left-handed metamaterials

Based on the electromagnetic theory,the Manly-Rowe relations for nonlinear left-handed metamaterials are studied.Energy conversion process and spatial distribution of forward-propagating wave of fundamental frequency and backward-propagating second harmonic wave under phase-matching condition are investigated.That a surface of nonlinear left-handed metamaterials operates as an effective mirror which reflects the energy in the form of second harmonics is demonstrated.Numerical results of field intensity distribution of a finite thickness metamaterial slab is given.Finally,the importance of phase-matching condition to the investigation of nonlinear left-handed metamaterials is illustrated from the viewpoint of phase-mismatching.This work provides a basis for studying nonlinear left-handed metamaterials.