Investigation on abnormal group velocities in 1D coaxial photonic crystals

Recently, controlling the propagation velocity of electromagnetic wave has been the object of many re- searches because it offers an extra degree of flexibility for processing signals. Reducing the transmission ve- locity, even stopping and storing the mi…     

V系统中实现群速度由慢光速到超光速的转换

在近简并的封闭三能级V系统中,一束弱激光探测场的群速度可以通过控制一单色驱动场的强度实现慢光速到超光速的转换.采用修饰态的方法在物理上解释了产生这种现象的可能原因.     

倒Y-型原子系统中增益辅助的慢光研究

通过外加驱动场并使其与四能级原子系统能级共振,能够改变四能级原子系统中的色散和吸收特性。研究表明,选择适当的参数,探测光场可被放大,即有增益产生。同时,探测光场增益-吸收系数表现为增益。这种现象正好和探测光场的慢光现象对应起来,即增益辅助的慢光。这样,在该种原子系统中,可以达到对探测光场有效观测的目的。而这种慢光传输的现象在高保真光纤延迟线和现代光学信息处理方面有潜在的应用价值。     

四能级原子系统中光脉冲的亚光速和超光速传播

提出在一个四能级原子系统中, 通过控制外加微波场的强度, 实现光脉冲的亚光速和超光速传播的理论模型. 分析了两个上能级间隔对光场群速度的影响, 并比较了四能级系统与三能级Λ系统之间的差异.      

Nonlinear optical properties and superluminal propagation in the ruby

In this review article,we summarized the study of the weak light nonlinear properties associated with group velocity change in the ruby.The ruby could be reduced to a two-level system,in which population oscillations could lead to a subluminal result.With the modulated TEM00 beam introduced into the ruby,self-phase modulation together with Fraunhofer diffractions and nondegenerate two-wave coupling between different spatial frequency components of the beam occurs at the same time.Population oscillations,sel...     

V-型原子系统中慢光孤子研究

研究有自发辐射诱导相干效应的寿命拓宽的V-型原子与一个弱探测光场共振相互作用的情况。研究表明在激光与原子介质高度共振情况下。选择合适的参量．该系统中有暗孤子产生。同时孤子的群速度是慢光速。