非对称耦合量子阱的二次谐波产生与量子阱参数关系研究

Relation between the Second-harmonic Intensity and Structural Parameters in Asymmetric Coupled Quantum Wells

采用反射式二次谐波产生 (SHG)方法对非对称Ⅱ Ⅵ族耦合量子阱Zn1 -xCdxSe ZnSe的非线性光学特性进行了研究。非中心对称性和阱间耦合效应在很大程度上增强了材料的非线性效应。发现在入射光和反射光均为p偏振 ,以及入射光和反射光分别为s偏振和p偏振两种情况下 ,SHG信号都随Cd含量x的增大而减小。与ZnSe基体材料相比 ,非对称耦合量子阱 (ACQW)在可见光波段的SHG信号增强一个量级以上。同时发现SHG信号随入射光偏振角的变化而周期性地变化。

The nonlinear optical characteristics in asymmetric coupled Zn1-x Cdx Se/ZnSe quantum wells have been investigated by using the reflective second harmonic generation (SHG) measurement technique. It is found that the SHG signal is enhanced in the interwell coupling, and the SHG intensity decreases with increasing x. The dependence of the SHG intensity (p-in/p-out, p-in/s-out) in the asymmetric coupled quantum wells on the incident polarization angle is also observed.