微腔旋转对耦合腔光波导群速度的影响

Effect of rotating cavities on the group velocities of the coupled-resonater optical waveguides

本文利用多重散射方法和时域有限差分方法,理论研究了微腔旋转对二维正方晶格光子晶体耦合腔光波导群速度的影响.研究结果表明,通过旋转微腔可以造成传播模的模式分裂,从而实现群速度的降低.当微腔旋转角度为45°时,传播模的群速度最小,两个传播模的群速度分别达到了0.0016倍和0.0009倍于真空光速,与微腔未旋转时相比降低了一个数量级.上述两种传播模群速度的差别是由传播模的空间对称性决定的.

In this article,the influence of cavity rotation on the group velocities of the coupled-resonator optical waveguides,which consists of the two-dimensional square-lattice photonic crystal,is studied theoretically by the multiple-scattering method and the finite-difference time-domain method. Simulation results show that the original single propagation mode becomes two modes when the cavities within the waveguide are rotated alternately,and the group velocities of the modes is reduced greatly. When the rotated angle of the selected cavities is 45°,the group velocities of the propagating modes can be reduced by one order of magnitude. Compared with that of the coupled-resonator optical waveguide without rotation of selected cavities,the two velocities get their minimum value,which are 0.0016c and 0.0009c respectively. The difference between them is determined by the symmetry of the propagating modes.