PML-FDTD法在分析负折射率材料中的应用

Analysis of Negative Refractive Index Materials with the PML-FDTD Method

将时域有限差分(FDTD)法引入了对负折射率材料物理现象的仿真研究.给出了二维TM波在负折射率材料中的时域差分方程,并且在吸收边界处使用了理想匹配层(PML).为了避免在迭代过程中出现的不稳定现象,在差分方程的推导中引入了Drude模型,并对Pendry提出的由负折射率材料构成的平板透镜具有的完美成像现象进行了数值仿真验证.由仿真结果发现,完美成像现象只在平板透镜的折射率n=-1时出现,当n≠-1时则会出现近轴聚焦效应.

The finite-difference time-domain （FDTD） method was introduced into the simulation of the physics phenomena of the negative refractive index materials （NIM）. The numerical formulation of the FDTD method for TM wave in the NIM materials was presented,and the perfectly matched layer （PML） was used in the absorption boundary condition. The Drude model was introduced, in order to avoid instability of the leapfrog in time domain, and the perfect lens phenomenon proposed by Pendry was simulated. The simulation results show the perfect lens only occur when the nslab = -- 1, otherwise, the paraxial focusing of the wave energy occurs.