Eigenstates and absorption spectra of interdiffused AlGaAs-GaAs multiple-quantum-well structures
Eigenstates and absorption spectra of interdiffused AlGaAs-GaAs multiple-quantum-well structures
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DOI：
10.1109/3.511553
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发表时间：
1996-08
影响因子：
2.5
通讯作者：
E. Li;B. Weiss;K. Chan
中科院分区：
文献类型：
--
作者：
E. Li;B. Weiss;K. Chan
本文对相互扩散的AlGaAs-GaAs多量子阱结构中的阱间耦合本征态进行了全面的分析。一个完整的数值计算被认为是没有任何近似或假设的本征态。在阱和势垒厚度等于100 /spl Aring/的量子阱结构中的初始相互扩散期间，波函数表现为几乎没有阱到阱耦合的状态的单量子阱的情况。然而，随着相互扩散的进行，在每个子带中的本征态形成迷你带，如在超晶格的情况下。耦合波函数的畸变也可以被观察到作为多量子阱芯的远侧处的受限威尔斯的非均匀性的结果。还计算了包括价带混合在内的偏振吸收系数。结果表明，在10 /spl Aring//spl les/L/sub d//spl les/30 /spl Aring/范围内，吸收边蓝移较大。二维量子阱特性在相互扩散开始时最强。对调制器性能的估计也显示出在互扩散的初始阶段期间对比度的改善和较低的吸收损耗。这预测了几乎60 nm的波长调谐范围。
We present a comprehensive analysis of the inter-well coupled eigenstates in interdiffused AlGaAs-GaAs multiple quantum-well structures. A full numerical calculation is considered without any approximation or presumption of the eigenstates. During the initial interdiffusion in the quantum-well structure with well and barrier thickness equaling 100 /spl Aring/, the wavefunctions behave as in the case of a single quantum well with almost no well-to-well coupling of the states. However, as interdiffusion proceeds, the eigenstate in each subband forms minibands, as in the case of superlattice. Distortion of the coupled wavefunctions can also be observed as a consequence of the nonuniformity of the confined wells at the far sides of the multiquantum-well core. The polarized absorption coefficients, including valence band-mixing, are also calculated. Results show that the blue shift of the absorption edge is greater in the range of 10 /spl Aring//spl les/L/sub d//spl les/30 /spl Aring/. The two-dimensional quantum-well properties are at its strongest in the beginning of interdiffusion. An estimation of the modulator performance also shows an improvement of the contrast ratio and lower absorption loss during the initial stage of interdiffusion. This predicts wavelength tuning range of almost 60 nm.