加入增益介质的表面等离子体激元耦合共振波导传输特性理论研究

摘要

将增益介质加入金属环构成的表面等离子体激元耦合共振波导,利用传输矩阵及时域有限差分方法研究了不同增益系数下该耦合共振波导的透射谱线、色散关系以及群折射率.结果表明,增益介质共振频率附近的反常色散及正常色散变化能有效影响由共振波导几何结构决定的色散关系曲线,且具有相反的效果,分别使其变得平坦和陡峭,从而放大和缩小由共振波导几何结构决定的群折射率.另外,增益系数随外加抽运光改变的特点使得加入增益介质的耦合共振波导具有传输性能可灵活调节特性.文章的研究对促进耦合共振波导在高密度光学集成中的广泛应用具有积极意义.%Active materials are proposed to fill into plasmonic coupled resonator optical waveguide constructed with metal rings.Optical properties including transmission,dispersion relation and group index of the waveguide are illustrated by performing the transfer matrix method analysis and the finite difference time domain simulation.The results show that the anomalous and the normal dispersions of the active material near the resonance frequency will help to flatten or slope the dispersion relation produced by the geometric structure,leading to an amplified or attenuated group index of the waveguide.Additionally,we can real-time tune the optical properties of the waveguide by electrically or optically pumping the active material.Our results verify a feasible way for the application of such a waveguide in high desity integration of optical circuits.