反铁磁晶体的红外频率特性

INFRARED FREQUENCY CHARACTERISTIC OF ANTIFERROMAGNETIC CRYSTAL

研究了红外频段非线性s偏振表面波在反铁磁晶体和电介质交界面上的频率特性 .求出了非线性色散方程 ,揭示了非线性s偏振表面波存在一个临界频率 ,低于这个频率 ,非线性s偏振波是后向表面波 .利用色散方程与边界条件详细讨论了非线性s偏振表面波的频率范围 .发现功率不再是决定导波频率范围的唯一因素 。

Frequency proper-ties of infrared nonlinear s-polarized surface waves, which transmit through the interface between a dielectric and a nonlinear antiferromagnet were studied. The nonlinear dispersion equation was derived. It is found that there is a critical frequency in the nonlinear s-polarized surface waves. Below this frequency, the nonlinear s-polarized waves on the interface are backward surface waves. Using the dispersion equation and boundary conditions, the frequency region of nonlinear s-polarized waves was discussed in detail. The results show that not only the power but also the ratio of dielectric constants of two materials can influence the frequency region significantly.