FDTD analysis of wave propagation in nonlinear absorbing and gain media
FDTD analysis of wave propagation in nonlinear absorbing and gain media
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DOI：
10.1109/8.662652
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发表时间：
1998-03
影响因子：
5.7
通讯作者：
A. Nagra;R. York
中科院分区：
文献类型：
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作者：
A. Nagra;R. York
提出了一种求解激光中可饱和吸收层和增益层等非线性介质中波传播的显式时域有限差分格式。该方案是辅助微分方程式FDTD方法的扩展，并结合了控制介质中原子布居的时间域动力学的速率方程。对于小信号强度和缓慢变化的脉冲，该方法与使用线性极化率函数的频域方法给出了相同的结果。计算了大信号强度下的布居动力学和快速变化脉冲在二能级(吸收体)和四能级(增益)原子介质中的瞬时响应，证明了该方法的优越性。
An explicit finite-difference time-domain (FDTD) scheme for wave propagation in certain kinds of nonlinear media such as saturable absorbers and gain layers in lasers is proposed here. This scheme is an extension of the auxiliary differential equation FDTD approach and incorporates rate equations that govern the time-domain dynamics of the atomic populations in the medium. For small signal intensities and slowly varying pulses, this method gives the same results as frequency-domain methods using the linear susceptibility function. Population dynamics for large signal intensities and the transient response for rapidly varying pulses in two-level (absorber) and four-level (gain) atomic media are calculated to demonstrate the advantages of this approach.