提出了一种基于光子晶体耦合波导实现光开关效应的方法:将线缺陷引入二维光子晶体以形成两平行的邻近波导,两邻近波导及其中间的两排介质柱构成了光开关模型耦合区;利用平面波展开法计算了不同介质填充率情况下的色散特性。结果发现:减小介质填充率可以实现波导耦合长度的减小;分段调整中间介质柱的填充率和选择不同的耦合搭配长度,定向耦合器内的光波可以与任意分段介质进行独立、互不相干地耦合,光信号可以在两耦合波导中进行受控地、不间断地交替传输,从而实现了光信号沿两不同端口受控输出的开关效应。

In this paper, we demonstrate a novel optical switching structure based on a coupled photonic crystal waveguides. The switching structure is formed by two closely spaced linear defect waveguides in a two-dimensional photonic crystal of air holes in semiconductor matrix. We investigate fill factor which affects dispersion diagram by using PWM methods. In the coupling region, we found that the input signal beam can be controlled by choosing a appropriate coupling length for exchanging singals between two output ports. The coupling efficiency is increased and the coupling length is also reduced by modifying the fill factor of the coupling region between the coupled waveguides.