Chen Yuetao, Chen Gaiqing, Luo Mengmeng, Chang Shoukang, Gao Shaoyan
Opt Express. 2023 Jul 17;31(15):25253-25266. doi: 10.1364/OE.494136.
We proposed a scheme to realize tunable giant Goos-Hänchen (GH) and Imbert Fedorov (IF) shifts of the Laguerre-Gauss (LG) beam on a guided-wave surface plasmon resonance (GWSPR) structure backed by a coherent atomic medium with the spontaneously generated coherence (SGC) effect. The orbital angular momentum carried by the incident LG beam can be applied to enhance and control IF shifts but is not beneficial to GH shifts. However, in the presence of SGC effect in the atomic medium, both GH and IF shifts can be simultaneously enhanced and well controlled. With the SGC effect, the linear absorption of the atomic medium vanishes, while the nonlinear absorption of that can be significantly enhanced and controlled by the trigger field, which contributes to controlling of the beam shifts. In particular, the direction of GH shifts can be switched by the Rabi frequency of the trigger field, which can be interpreted as the result of a competition between the inherent damping and the radiative damping corresponding to the nontrivial change in the loci of the reflection coefficients. This scheme provides an effective method to flexibly control and enhance the beam shifts, so it has potential applications in integrated optics, optical sensors, etc.
我们提出了一种方案，以在具有自发产生相干性（SGC）效应的相干原子介质支持的导波表面等离子体共振（GWSPR）结构上实现拉盖尔 - 高斯（LG）光束的可调谐巨古斯 - 汉欣（GH）和因伯特 - 费多罗夫（IF）位移。入射LG光束携带的轨道角动量可用于增强和控制IF位移，但对GH位移不利。然而，在原子介质中存在SGC效应时，GH和IF位移都可以同时增强并得到很好的控制。由于SGC效应，原子介质的线性吸收消失，而其非线性吸收可以通过触发场显著增强和控制，这有助于控制光束位移。特别地，GH位移的方向可以通过触发场的拉比频率切换，这可以解释为反射系数轨迹的非平凡变化所对应的固有阻尼和辐射阻尼之间竞争的结果。该方案提供了一种灵活控制和增强光束位移的有效方法，因此在集成光学、光学传感器等方面具有潜在应用。
