Speaker
Description
Advances in silicon photonics have so far largely focused on the development of classical optoelectronic devices. While there has been great success in this classical field of photonics, the development of silicon-compatible quantum photonics components, which can be combined with cost-efficient silicon electronics, has faced significant challenges, particularly regarding the growth of high-quality single quantum dots (QDs) on silicon substrates.
Here, we demonstrate the direct growth of InGaAs QDs emitting at 940 nm with excellent quantum optical properties on a silicon platform \cite{1}. Through the heteroepitaxy of GaAs structures on a silicon substrate using an intermediate GaP buffer layer, we observe high multi-photon suppression ($g^{(2)}(0) = (3.7 \pm 0.2) \times 10^{-2}$) and good photon indistinguishability ($V_{\text{HOM}} = (66 \pm 19)\%$) under non-resonant excitation. Moreover, we achieve a photon extraction efficiency (PEE) of up to $(18 \pm 2)\%$ in a simple planar device structure with a backside DBR, indicating a high internal quantum efficiency of the QDs.
Additionally, we shift the emission wavelength of the Si-compatible InGaAs QDs into the telecom O-band using a strain-reducing layer (SRL) approach. The emitters are subsequently integrated into bullseye cavities through in-situ electron beam lithography (EBL). The resulting structure demonstrates a PEE of $(40 \pm 1)\%$ and a single-photon purity of $(99.9 \pm 0.1)\%$ at 4 K, decreasing to $(85 \pm 1)\%$ at 40 K. These results indicate the emitter's potential for operation with Stirling cryocoolers, maintaining high performance at elevated cryogenic temperatures.
