量子相干表面等离子体谐振系统中古斯-汉欣位移的控制

Controlling of Goos-Hnchen Shift in Quantum Coherence Surface Plasmon Resonance System

当光束在两种介质的分界面上发生全反射时,反射光会产生横向的古斯-汉欣(GH)位移。在Kretschmann结构中引入原子介质,利用耦合光激发表面等离子体波,研究了表面等离激元辅助的干涉效应作用下探测光的反射GH位移。通过对比耦合光分别为行波和表面等离子体波时探测光的反射率和反射GH位移,发现当探测光入射角偏离谐振角时,反射率曲线会出现类似Fano共振的不对称性,反射GH位移关于探测光失谐量有一段线性变化区域,且可以在正负之间变化;当耦合光为表面等离子体波时,反射GH位移对探测光失谐量的变化更敏感。

When the beam is totally reflected on the interface between two media, the reflected light has a transverse Goos-H^nchen （GH） shift. An atomic medium is introduced in the Kretschmann structure, and the surface plasmon wave is excited by the coupling light. The reflective GH shift of probe light under the surface plasmon assisted interference effect is studied. When the free propagating wave and the surface plasmon wave are respectively used as the coupling light, the reflectivity and the reflective GH shift of probe light are compared. It is shown that there is an asymmetric line-shape similar to Fano resonance in the reflectivity curve when the incident angle of the probe light deviates from the resonance angle, and the reflective GH shift can shift linearly between positive and negative values. When the coupling light is the surface plasmon wave, the reflective GH shift is more sensitive to the variation of the detuning of the probe beam.