Cavity-enhanced excitation of a quantum dot in the picosecond regime
Cavity-enhanced excitation of a quantum dot in the picosecond regime
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DOI：
10.1088/1367-2630/acf33b
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发表时间：
2023-01
影响因子：
3.3
通讯作者：
A. Javadi;N. Tomm;N. Antoniadis;A. Brash;R. Schott;S. Valentin;A. Wieck;A. Ludwig;R. Warburton
中科院分区：
文献类型：
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作者：
A. Javadi;N. Tomm;N. Antoniadis;A. Brash;R. Schott;S. Valentin;A. Wieck;A. Ludwig;R. Warburton
用单个发射器产生单光子的一个主要挑战是激发发射器，同时避免激光泄漏到收集路径中。理想情况下，任何抑制这种泄漏的方案都不应导致单光子源效率的损失。在这里，我们研究了一个方案，其中一个单一的发射极，半导体量子点，嵌入在微腔。该方案利用分裂成两个正交偏振模式的腔模式：一个模式用于激发，其他收集。通过将实验与理论联系起来，我们证明了最好的粒子数反转是用与量子发射体失谐的激光脉冲实现的。拉比振荡表现出不寻常的依赖于脉冲功率。我们的理论定量地描述了它们，使我们能够确定绝对的粒子数反转。通过将实验结果与我们的理论模型进行比较，我们确定了最佳激光失谐的粒子数反转为98%−5%+1%。拉比振荡依赖于激光脉冲失谐的符号，这是一种由声子对激子动力学的非平凡效应引起的现象。激子-声子相互作用包括在理论中，并给出了所有的实验结果非常符合。
A major challenge in generating single photons with a single emitter is to excite the emitter while avoiding laser leakage into the collection path. Ideally, any scheme to suppress this leakage should not result in a loss in the efficiency of the single-photon source. Here, we investigate a scheme in which a single emitter, a semiconductor quantum dot, is embedded in a microcavity. The scheme exploits the splitting of the cavity mode into two orthogonally-polarised modes: one mode is used for excitation, the other for collection. By linking the experiment to theory, we show that the best population inversion is achieved with a laser pulse detuned from the quantum emitter. The Rabi oscillations exhibit an unusual dependence on pulse power. Our theory describes them quantitatively, enabling us to determine the absolute population inversion. By comparing the experimental results with our theoretical model, we determine a population inversion of 98%−5%+1% for optimal laser detuning. The Rabi oscillations depend on the sign of the laser-pulse detuning, a phenomenon arising from the non-trivial effect of phonons on the exciton dynamics. The exciton–phonon interaction is included in the theory and gives excellent agreement with all the experimental results.