Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, Australian Capital Territory, 2601, Australia.
Nano Lett. 2016 Aug 10;16(8):5080-6. doi: 10.1021/acs.nanolett.6b01973. Epub 2016 Jul 29.
We present the design and room-temperature lasing characteristics of single nanowires containing coaxial GaAs/AlGaAs multiple quantum well (MQW) active regions. The TE01 mode, which has a doughnut-shaped intensity profile and is polarized predominantly in-plane to the MQWs, is predicted to lase in these nanowire heterostructures and is thus chosen for the cavity design. Through gain and loss calculations, we determine the nanowire dimensions required to minimize loss for the TE01 mode and determine the optimal thickness and number of QWs for minimizing the threshold sheet carrier density. In particular, we show that there is a limit to the minimum and maximum number of QWs that are required for room-temperature lasing. Based on our design, we grew nanowires of a suitable diameter containing eight uniform coaxial GaAs/AlGaAs MQWs. Lasing was observed at room temperature from optically pumped single nanowires and was verified to be from TE01 mode by polarization measurements. The GaAs MQW nanowire lasers have a threshold fluence that is a factor of 2 lower than that previously demonstrated for room-temperature GaAs nanowire lasers.
我们提出了含有同轴 GaAs/AlGaAs 多量子阱 (MQW) 活性区的单根纳米线的设计和室温激光特性。TE01 模式，具有环形强度分布，主要在 MQW 平面内偏振，预计在这些纳米线异质结构中激射，因此被选为腔设计。通过增益和损耗计算，我们确定了最小化 TE01 模式损耗所需的纳米线尺寸，并确定了最小化阈值薄片载流子密度所需的最佳厚度和量子阱数量。特别是，我们表明，对于室温激射，所需的量子阱数量存在最小和最大限制。基于我们的设计，我们生长了具有合适直径的纳米线，其中包含八个均匀的同轴 GaAs/AlGaAs MQW。从光泵浦的单根纳米线中观察到室温激光，并通过偏振测量验证其来自 TE01 模式。GaAs MQW 纳米线激光器的阈值能量比以前报道的室温 GaAs 纳米线激光器低 2 倍。
