含色散介质的一维光子晶体微腔中简正耦合模的物理图像  

Physical Model on Normal Coupled Modes in a Symmetric One-dimensional Photonic Crystal

作　　者：陈淑文[1] 汪先明[1] 李鸿[1] 何弦[1] 吴评[1] 

机构地区：[1]南昌大学理学院物理系,江西南昌330047

出　　处：《发光学报》2005年第6期699-703,共5页Chinese Journal of Luminescence

基　　金：国家自然科学基金(10547119);南昌大学基础理论基金(2005)资助项目

摘　　要：对一维光子晶体中的色散介质采用洛仑兹振子模型,对线性层及色散δ层均采用传输矩阵的方法,研究了一维含色散介质的光子晶体微腔中的简正耦合模。通过改变洛仑兹振子和微腔之间的失谐频率,分析了简正耦合模频率的变化情况。在失谐频率比较大时,光与洛仑兹振子间的耦合作用较小,简正耦合模中的一个接近腔模频率,而另一个则接近洛仑兹振子的共振频率;在失谐频率比较小时,光与洛仑兹振子间的耦合作用较大,简正耦合模与未耦合的腔模频率和洛仑兹振子的共振频率之间的差别较为明显。最后通过引进该结构的复有效折射率,对含色散介质的系统,由于带隙中间的共振模被湮灭并分裂为左右两个耦合模,其复有效折射率虚部在原共振峰处跃变为一较大值,而在新生成的两个耦合模附近趋近于零,光与色散介质相互耦合而形成的腔极化激元的物理图像十分清晰。Recently, there has been significant interest in studies of the localization of electromagnetic waves （EW） in photonic band-gap （PBG） materials. The interest is partially due to the fact that the interactions between the electrons don＇t exist any longer and the experiments can be performed at the room temperature. Furthermore, the special property of the control of propagation of light in the PBG has potential applications in many optical devices. One or multiple transmission peaks can be intentionally created in the forbidden gap, which have demonstrated their potential applications in the fabrication of lasers, light-emitting diodes, and single or multiple channeled filters, and so on. On the other hand, optical response of normal-mode coupling semiconductor microcavities have attracted special interests for researchers. Optical microcavities can confine light to small volumes by resonant recirculation. Devices based on optical microcavities are already indispensable for a wide range of applications and studies such as light-emitting diodes with high-efficiency and good-quality, optical switches, logic gates, lasers, photoluminescence devices, photonic crystal waveguides and so on. We investigate the normal-mode coupling dispersive medium in a symmetric 1D PCs. We use oscillator model to simulate the linear susceptibility of the dispersive layer. Given a reduced oscillator HWHM linewidth and a reduced frequency of the oscillator resonance, the single longitudinal defect mode will be split into two transmission peaks due to a high dispersive absorption. It is found that the separation between the two transmission peaks enlarges with increasing the dimensionless coupling strength. That means we can modulate the frequency shift of the dispersive defect by adjusting the parameter of the dispersive medium. We have also calculated the relationship between NMC and the oscillator, detuning effect of the cavity. By introducing a concept of complex effective refractive index, we calculated the imaginary part

关 键 词：光子晶体 色散介质 复有效折射率 透射谱 

分 类 号：O472.3[理学—半导体物理] O436[理学—物理]