Theory of the anisotropy of ultrafast nonlinear refraction in zinc-blende semiconductors.
Theory of the anisotropy of ultrafast nonlinear refraction in zinc-blende semiconductors.
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闪锌矿半导体超快非线性折射各向异性理论。
DOI：
10.1103/physrevb.52.8150
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
B. Wherrett
中科院分区：
文献类型：
--
作者：
D. Hutchings;B. Wherrett
计算了高导带组${\mathit{\ensuremath{\Gamma}}}_{15}^{\mathit{c}}$对超快非线性折射率系数（${\mathit{n}}_{2}$）的强度、线性/圆二色性和各向异性在锌混合半导体GaAs和InSb基本吸收边缘以下透明光谱区域的影响。各向异性完全是由于高波段的影响。对于砷化镓，在双光子带边缘，对于线偏振光，预测${\mathit{n}}_{2}$随着晶体取向相对于偏振方向的改变而变化55%。在更长的波长上，预计会有更大的变化。InSb的低得多的预测各向异性与先前讨论的双光子吸收的基本带隙与高带隙之比的各向异性系数强度的近似公式是一致的。讨论了这种${\mathit{n}}_{2}$各向异性对单束和双束传输的影响。并对光开关优值的各向异性进行了评价。在刚好低于带边缘的频率处，发现平行于[001]晶体方向的辐射线极化图最大；在半带隙以上和较低频率下[111]，线偏振或任何圆偏振都是有利的。
The influence of the higher-conduction-band set ${\mathrm{\ensuremath{\Gamma}}}_{15}^{\mathit{c}}$ on the strength, linear/circular dichroism, and anisotropy of the ultrafast nonlinear refractive index coefficient (${\mathit{n}}_{2}$) is calculated across the transparent spectral region below the fundamental absorption edge for the zinc-blend semiconductors GaAs and InSb. The anisotropy is due entirely to the effects of the higher bands. For GaAs, at the two-photon band edge, and for linearly polarized light, ${\mathit{n}}_{2}$ is predicted to vary by 55% as the crystal orientation is altered relative to the polarization direction. Even larger variations are expected at longer wavelengths. The far lower predicted anisotropy of InSb is consistent with the approximate formula for the strength of the anisotropy coefficient in terms of the ratio of the fundamental to the higher band gap discussed previously for two-photon absorption. The influence of such ${\mathit{n}}_{2}$ anisotropy on propagation in both one-beam and two-beam configurations is discussed. The anisotropy of the optical-switching figure of merit is also evaluated. At frequencies just below the band edge the figure is found to be greatest for radiation linearly polarized parallel to the [001] crystallographic direction; just above the half-band gap and at lower frequencies [111] linear polarization or any circular polarization is favored.