Dispersive Properties of tunnelling—induced transparency in an asymmetric double quantum well

We have investigated the dispersive properties of tunnelling-induced transparency in asymmetric double quantum well structures where two excited states are coupled by resonant tunnelling through a thin barrier in a three-level system of electronic subbands. The intersubband transitions exhibit high dispersion at zero absorption, which leads to the slow light velocity in this medium as compared with that in vacuum (c=3×10⁸). The group velocity in a specific GaAs/AlGaAs sample is calculated to be v_g=c/4.30. This structure can be used to compensate for the dispersion and energy loss in fibre optical communications.     

A bistable system with an electromagnetically induced grating

We propose a scheme of a bistable system with an electromagnetically induced grating and analyse the optical bistabilities in the system.The stationary equations describing the system have been derived.This bistable system shows typical hysteresis behaviour.     

基于GaAs-AlGaAs非对称耦合量子阱材料的半导体弱光开关

提出了一种基于在GaAs-AlGaAs非对称耦合量子阱材料子带跃迁的量子干涉的半导体弱光开关，分析了驰豫速率γ21对光开关的影响，这种半导体弱光开关是半导体超晶格材料共振隧穿作用导致的子带跃迁的Fano干涉的结果，由于半导体结构与材料可以人为地选择，相干强度可以控制和改变，这种半导体弱光开关比采用原子系统更实用，这也是一种在半导体材料中实现一束光控制另一束光的方法。     

石墨烯和对称开口谐振环超材料中可调谐的双等离激元诱导透明现象

提出了由石墨烯和两对对称开口谐振环构成的等离激元诱导透明(PIT)超材料结构,该PIT超材料结构之间的耦合形式为暗-亮-暗模式.通过有限元方法模拟,观察到双PIT透明窗口,通过改变石墨烯的费米能级或者改变开口谐振环的几何参数来动态地调制PIT窗口.理论结果表明,当石墨烯与两对对称的开口谐振环之间的相互作用距离为0.5 μm、石墨烯费米能级为1.5 eV时,可得到最优的双透明窗口.双PIT效应在非线性器件、可调谐传感器、开关和慢光器件等方面有潜在的应用价值.