Refractive Index Dynamics and Linewidth Enhancement Factor in $p$-Doped InAs–GaAs Quantum-Dot Amplifiers
Refractive Index Dynamics and Linewidth Enhancement Factor in $p$-Doped InAs–GaAs Quantum-Dot Amplifiers
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$p$ 掺杂 InAs–GaAs 量子点放大器中的折射率动态和线宽增强因子
DOI：
10.1109/jqe.2009.2013110
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发表时间：
2009
影响因子：
2.5
通讯作者：
W. Langbein
中科院分区：
文献类型：
--
作者：
V. Cesari;P. Borri;M. Rossetti;A. Fiore;W. Langbein
使用泵浦-探测差分传输实验外差检测，我们测量的折射率动力学在基态激子跃迁电泵浦InAs/GaAs量子点放大器发射近1.3妈妈在室温下。我们比较了三个样品不同的p型掺杂的水平，并考虑到在这些设备中的增益动态解释测得的指数变化。我们发现，在吸收中，由于p型掺杂的过量空穴密度加速恢复并降低折射率变化，因为通过p型掺杂填充空穴状态使空穴布居中的诱导变化向高能态移动。相反，在增益中，与在相同模态增益下操作的未掺杂器件相比，p掺杂器件中激发态中的减少的电子库导致较慢的增益恢复动力学和较大的折射率变化。从这些测量推断的线宽增强因子表明，p掺杂是有效的，主要是由于在增益制度中的p掺杂器件的较大的差分增益，在减少这个参数。
Using a pump-probe differential transmission experiment in heterodyne detection, we measured the refractive index dynamics at the ground-state excitonic transition in electrically pumped InAs/GaAs quantum-dot amplifiers emitting near 1.3 mum at room temperature. We compare three samples differing only in the level of p-doping, and interpret the measured index changes taking into account the gain dynamics in these devices. We find that in absorption, the excess hole density due to p-doping accelerates the recovery and reduces the refractive index change, since filling of the hole states by p -doping shifts the induced changes in the hole population toward high energy states. Conversely, in gain, the reduced electron reservoir in the excited states in p -doped devices results in slower gain recovery dynamics and in larger refractive index changes compared to undoped devices operating at the same modal gain. The linewidth enhancement factor inferred from these measurements shows that p-doping is effective in reducing this parameter mainly due to the larger differential gain in p-doped devices in the gain regime.