Photonic crystal (PhC) nanocavities with high quality (Q) factors have attracted much attention because of their strong spatial and temporal light confinement capability. The resulting enhanced light–matter interactions are beneficial for diverse photonic applications, ranging from on-chip optical communications to sensing. However, currently achievable Q factors for active PhC nanocavities, which embed active emitters inside, are much lower than those of the passive structures because of large optical loss, presumably originating from light scattering by structural imperfections and/or optical absorptions. Here, we demonstrate a significant improvement of Q factors up to ∼160 000 in GaAs active PhC nanocavities using a sulfur-based surface passivation technique. This value is the highest ever reported for any active PhC nanocavities with semiconductor quantum dots. The surface-passivated cavities also exhibit reduced variation in both Q factors and cavity resonant wavelengths. We find that the improvement in the cavity performance presumably arises from suppressed light absorption at the surface of the PhC’s host material by performing a set of PL measurements in spectral and time domains. With the surface passivation technique, we also demonstrate a strongly coupled single quantum dot-cavity system based on a PhC nanocavity with a high Q factor of ∼100 000. These results will pave the way for advanced quantum dot-based cavity quantum electrodynamics and GaAs micro/nanophotonic applications containing active emitters.

中文翻译：

---

具有量子点的表面钝化高QGaAs光子晶体纳米腔

具有高品质（Q）因子的光子晶体（PhC）纳米腔因其强大的时空光限制能力而备受关注。由此产生的增强的光质相互作用对于从片上光通信到传感的各种光子应用都是有益的。但是，由于内置了大量的光损耗，大概是由结构缺陷和/或光吸收引起的光散射引起的，因此目前在有源PhC纳米腔中可实现的Q因子远低于无源结构的Q因子，这些有源因子嵌入了有源发射极。在这里，我们证明了Q的显着改善使用基于硫的表面钝化技术，可在GaAs活性PhC纳米腔中产生高达约160000的杂质。对于具有半导体量子点的任何活性PhC纳米腔，该值是有史以来最高的。表面钝化的腔体在Q因子和腔体共振波长方面也表现出减小的变化。我们发现，通过在光谱和时域中执行一组PL测量，可以抑制PhC主体材料表面的光吸收，从而提高腔性能。利用表面钝化技术，我们还展示了基于具有高Q值的PhC纳米腔的强耦合单量子点腔系统 系数约为100000。这些结果将为先进的基于量子点的腔量子电动力学和包含有源发射器的GaAs微/纳米光子应用铺平道路。