A plasmonic cavity filled with active material is proposed to explain optical switching. Optical properties, including transmission, response time, and field distribution of on/off state, are numerically investigated. We demonstrate that such a gain-assisted plasmonic structure can achieve optical switching in the nanodomain and shorten the switching time to the subpicosecond level. Our results indicate the potential application of the proposed structure in optical communication and photonic integrated circuits.

利用时域有限差分方法(FDTD)研究了由十二重准周期光子晶体(PQ)局部结构组成的复合二维(2D)光子晶体(PC)及其点缺陷的光学特性。结果表明，由于准周期光子晶体局部结构平移对称性缺失，该复合光子晶体可以通过改变缺陷位置来调节缺陷模的特性，由此具有比周期光子晶体更为丰富的缺陷模式及更灵活的调节方式。同时，研究表明，缺陷模频率与所去除介质柱之间的相互影响强弱具有关联性。通过不同点缺陷腔的组合可以进一步获得灵活多样的缺陷模式。