基于相变与悬链线连续相位调控的超构光子开关  

Photonic meta-switch based on phase change and catenary-enabled continuous phase regulation

作　　者：宋睿睿 邓钦玲 周绍林[1,2] Song Rui-Rui;Deng Qin-Ling;Zhou Shao-Lin(School of Microelectronics,South China University of Technology,Guangzhou 510640,China;Pazhou Lab,Guangzhou 510335,China)

机构地区：[1]华南理工大学微电子学院,广州510640 [2]琶洲实验室,广州510335

出　　处：《物理学报》2022年第2期363-370,共8页Acta Physica Sinica

摘　　要：针对超表面相位调控中的无源及离散特性,本文拟将等宽悬链线超构单元与非易失性相变介质结合,探索研究一种高效连续相位调制的双稳态相变有源波前超构开关.首先在9—10μm之间的宽带中红外波段实现了可动态切换的波前偏转开关;当相变层在非晶态和晶态之间切换时,入射光波前分别呈现异常反射和正常的镜面反射,即"开"或"关"两个偏转状态.其次展示了一种可动态切换的高阶贝塞尔光束开关:非晶态时,9.6μm波长垂直入射下交叉极化转换效率接近100%,产生正常的几何相位调控与二阶贝塞尔聚焦,即"开"态;而相变至晶态时,交叉极化与几何相位调控被"关"闭.本质上,自旋-轨道相互作用具有无色散的相位调控保证了该类器件的宽波段工作特性,在未来的有源光电子集成、光通讯等应用领域中具有重大潜力.Aiming at the characteristics of passive and discrete phase regulations inherent in current metasurfaces,we combine optimized isowidth catenary with non-volatile phase change dielectrics and explore a type of bistable phase-change-based wavefront meta-switch of continuous phase tuning and active switching.First,the switchable wavefront deflector is demonstrated in the mid-IR range between 9μm and 10μm.Upon phase transition between crystalline state and amorphous state,the incident wave can be switched into anomalous reflection and regular reflection,i.e.the“on”state and“off”state of wave deflection.Further,a type of dynamically tunable Bessel beam switch is demonstrated.In the amorphous state,the polarization conversion efficiency approaches to 100%with an incident wave of 9.6μm in wavelength.Therefore,the normal geometrical phase and the second-order Bessel focus are switched“on”.However,the cross-polarization and geometrical phase are switched“off”upon phase changing into crystallized state.Intrinsically,non-dispersive spin-orbit interaction ensures that this kind of device possesses the broadband characteristics.Such a devise has great potential applications in active optoelectronic integration,optical communications,etc.

关 键 词：相变 超材料与超表面 超构器件 光子开关 

分 类 号：O439[机械工程—光学工程]