光子晶体耦合腔波导中的慢光特性研究

A Study on the Slow-Light Characteristics of Photonic Crystal Coupled Cavity Waveguide

研究了二维光子晶体耦合腔波导的慢光传输特性.利用平面波展开法分析不同结构的耦合腔波导的色散曲线.分析发现,光子晶体耦合腔波导的慢光特性与点缺陷微腔的几何尺寸有关.通过调制点缺陷的半径可以改变慢光导模的中心频率.另外发现,点缺陷微腔间距也是影响耦合腔波导慢光特性的重要参数.增大距离n,零色散点导模的群速度明显下降,可以获得群速度为0.005c的慢光模式,而导模的中心频率变化不大.该分析结果为设计不同要求的慢光波导结构提供重要参考.

The slow-light characteristics of 2D dispersion photonic crystal coupled cavity waveguide have been studied based on the plane wave expansion method. The dispersion curves of coupled cavity waveguides with different structure are also analyzed. The study revealed that there is relationship between slow-light properties and the dimension of defect micro-cavities; the center frequency of the slow-light mode can change under the tuning of point defect radius. In addition, the distance between the micro-cavities is an important factor that affects the slow-light characteristics of coupled cavity waveguide. With the increase of the distance n, group velocity of guided modes at the zero dispersion point decreased significantly. The group velocity of 0.005 c could be obtained and the center frequency of guide mode changes little. The results provide an important reference for the design of slow-light waveguide with different requirements.