FDTD Analysis of Two-Photon Absorption and Free-Carrier Absorption in Si High-Index-Contrast Waveguides
FDTD Analysis of Two-Photon Absorption and Free-Carrier Absorption in Si High-Index-Contrast Waveguides
复制标题
硅高折射率波导中双光子吸收和自由载流子吸收的 FDTD 分析
DOI：
10.1109/jlt.2007.903298
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发表时间：
2007
影响因子：
4.7
通讯作者：
N. Suzuki
中科院分区：
文献类型：
--
作者：
N. Suzuki
双光子吸收（TPA）、自由载流子吸收（FCA）和载流子等离子体效应在硅基光子器件中起着重要的作用。这些影响已被直接纳入时域有限差分（FDTD）模拟器的第一次。为了验证FDTD模拟器的有效性，将其应用于超短光脉冲在短硅高折射率对比波导中的非线性传输的模拟。计算结果与文献结果一致。轻微负斜率传输的原因解释如下。由于TPA诱导的FCA使得脉冲形状不对称，具有较高光输入强度的脉冲倾向于具有较长的尾部。因此，较强的光脉冲经受FCA的时间较长，导致负差分传输。
The two-photon absorption (TPA), the free-carrier absorption (FCA), and the carrier plasma effect play important roles in Si-based photonic devices. These effects have been incorporated directly into a finite-difference time-domain (FDTD) simulator for the first time. To check the validity of the FDTD simulator, it has been applied to the simulation of nonlinear transmission of an ultrashort optical pulse in a short Si high-index-contrast waveguide. The results are consistent with those shown in the literature. The cause of the slight negative slope transmission has been explained as follows. Since the TPA-induced FCA makes the pulse-shape asymmetric, a pulse with a higher optical input intensity tends to have a longer tail. Therefore, a stronger optical pulse is subject to FCA for a longer period, resulting in the negative differential transmission.