回音壁模式圆盘形微谐振腔的设计及特性研究

针对光通信波段,分析了标准圆盘形结构和其他三种变体结构的WGM微谐振腔,讨论了通过改变传输波导和微腔之间的间距以及改变传输波导的几何形状对耦合系数的影响,基于FDTD算法,分别计算了四种结构的耦合系数、谐振频率、模场分布及品质因数等,发现模式的匹配程度和输入波导的弯曲损耗均对品质因数有影响,而四种结构的品质因数和耦合系数的变化规律相反,故具体应用中为了达到较高的耦合效率,须在较高的品质因数与较大的耦合系数之间进行折中,经比较得到了一种输入波导弯曲的优化圆盘形结构。

Design and Properties of the Microdisk Resonant Cavity with Whispering Gallery Mode

A standard microdisk and three kinds of variable microdisks resonant cavity with whispering gallery mode (WGM) are presented. By controlling the distance between waveguiding and micro-disk resonant cavity, as well as changing the geometry which can influence the coupling coefficient of the waveguiding and resonant cavity,  the coupling coefficients, resonant frequences, the distribution of modes, and Q-factors from mentioned four structures are calculated based on FDTD method. The degree of mode matching and the bending loss from input waveguide have influence on the Q-factors. There is opposite trend between the Q-factors of the four structures and the coupling coefficient. In order to obtain more efficient coupling efficiency, it is necessary to find a medium between the higher Q-factors and the larger coupling coefficient. Finally, an optimal microdick with curve input waveguide are obtained.