一种色散介质FDTD通用吸收边界

由单轴各向异性介质所满足的场方程出发，并根据相位匹配原理以得到介质中的色散关系和无反射条件.结合频域到时域的转换关系（即用/t代替jω）和移位算子时域有限差分（SO-FDTD）方法提出了一种适用于各向同性常见色散介质模型，包括德拜模型、洛伦兹模型、德鲁德模型等的通用UPML吸收边界.数值结果表明了该算法的通用性和高效性. 关键词： 时域有限差分 吸收边界 移位算子 色散介质

A finite difference time domain absorbing boundary condition for general frequency-dispersive media

The dispersion relations and the reflectionless conditions are obtained by the Maxwell’s curl equations in a uniaxial anisotropic medium and the phase-matching. Using the shift operator finite difference time domain （SO-FDTD） method and the transform relationship of frequency domain to time domain （jω replaced by /t）, an FDTD absorbing boundary condition for three kinds of general dispersive media model, i.e. the Debye model, Lorentz model and Drude model, is given. The characteristics of our absorbing boundary condition are tested. The computed results illustrated the generality and the feasibility of the scheme.