Cui Weina, Zhu Yongyuan, Huang Wanxia, Li Hongxia
National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, People's Republic of China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Dec;86(6 Pt 2):066604. doi: 10.1103/PhysRevE.86.066604. Epub 2012 Dec 19.
We investigate analytically the subwavelength plasmonic lattice solitons excited in an optical plasmonic waveguide consisting of a chain of nanorods embedded in a Kerr nonlinear optical medium with strong near-field interactions. A nonlinear lattice equation with onsite and intersite nonlinear terms describing the plasmon wave propagating along the chain is derived. Stability analysis predicts that modulation instability can occur and that, correspondingly, conditions for localized modes will exist. We analyze the nonlinear excitations for genuine discreteness and nonlinearity enhanced by the fields strongly confined in the nanosized dielectric gaps. Based on a quasidiscreteness approach, we obtain a nonlinear Schrödinger equation and find that the system supports bright and dark soliton solutions in different frequency bands. It is also shown that the existence of different solitons depends strongly on the type of nonlinearity of the embedded medium.
我们对在由嵌入具有强近场相互作用的克尔非线性光学介质中的纳米棒链组成的光学等离子体波导中激发的亚波长等离子体晶格孤子进行了分析研究。推导了一个包含在位和近邻非线性项的非线性晶格方程，用于描述沿链传播的等离子体波。稳定性分析预测可能会发生调制不稳定性，相应地，也会存在局域模的条件。我们分析了由纳米尺寸介电间隙中强烈受限的场增强的真正离散性和非线性的非线性激发。基于准离散方法，我们得到了一个非线性薛定谔方程，并发现该系统在不同频带支持亮孤子和暗孤子解。还表明，不同孤子的存在强烈依赖于嵌入介质的非线性类型。
