不同材料逆古斯汉欣位移机理的对比研究

Physical Mechanism of the Inverse Goos-Hnchen Shift of Different Materials

通过计算分界面附近的能流矢量曲线,对贵金属、超材料和负折射光子晶体表面的逆古斯汉欣位移的物理机制进行了研究.结果表明,虽然一定频率的入射光波在这3类材料表面反射时都能产生逆古斯汉欣位移,但逆古斯汉欣位移发生的物理机制完全不同.金属表面产生的逆古斯汉欣位移是因为TM偏振入射光诱导金属表面自由电子振荡,从而激发表面等离子体波;超材料表面产生的逆古斯汉欣位移是因为反射光束相对入射光束发生了相位突变;负折射光子晶体表面产生的逆古斯汉欣位移是光子晶体的等效负折射效应和周期性表面的综合作用,即全反射时激发了后向表面波.

Based on the calculation of the energy flux around the interface,the physical mechanisms of inverse Goos-Hnchen（GH）shifts on the surfaces of noble metal,metamaterial and negatively refractive photonic crystals were investigated.The results show that,although the inverse GH shifts may occur on the surfaces of three kinds of material in a similar manner,the physical mechanisms corresponding to those phenomena are completely distinct.The inverse GH shift of noble metal is based on the fact that the incidence of TM polarized light induces the oscillations of delocalized electrons at the surface of noble metal,which results in a surface plasmon wave.The GH shift of metamaterial is due to the mutation of the phase of reflectivity and the reason for negatively refractive photonic crystal is the synthetic action of effective negative refraction and periodicity of surface,i.e.,the excitation of backward surface wave.