The majority of photonic quantum information technologies rely on single photons that have high purity and indistinguishability. Although solid-state quantum emitters can serve such single photons on demand, their asymmetric temporal and spatial mode profiles limit the optimal efficiency and fidelity of quantum interaction. Here, we demonstrate single-photon pulses at a telecom wavelength with a Gaussian-like temporal mode profile from a cavity-coupled single quantum dot. Engineering the exciton dynamics via multi-exciton cascade recombination and cavity detuning enables us to modify the rise and decay dynamics of single excitons. Furthermore, the cascade recombination process temporally retards the single-exciton emission from the background emission, leading to possible purification of single photons at high excitation power. In addition, coupling quantum dots into a low Q cavity mode leads to a Gaussian-like spatial mode profile, which brings a high collection efficiency. This approach paves the way for producing single photons with an optimized temporal and spatial waveform.

中文翻译：

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通过单个量子点中的工程激子动力学对单光子进行时间整形

大多数光子量子信息技术依赖于具有高纯度和不可区分性的单光子。尽管固态量子发射器可以按需提供此类单光子，但其不对称的时间和空间模式分布限制了量子相互作用的最佳效率和保真度。在这里，我们展示了来自腔耦合单量子点的具有类似高斯时间模式轮廓的电信波长的单光子脉冲。通过多激子级联重组和腔失谐来设计激子动力学使我们能够修改单个激子的上升和衰减动力学。此外，级联重组过程在时间上延迟了背景发射的单激子发射，从而可能在高激发功率下净化单光子。此外，Q腔模式导致类似高斯的空间模式轮廓，带来高收集效率。这种方法为产生具有优化的时间和空间波形的单光子铺平了道路。