Seminarium Fizyki Ciała Stałego

In this seminar, I will present our recent progress in quantum photonic integrated circuits (QPICs) for quantum information processing in the telecom C-band around 1550 nm, where compatibility with optical-fibre networks enables direct links to existing communication infrastructure. The main focus will be on single-photon (flying-qubit) sources based on self-assembled InAs/InP semiconductor quantum dots (QDs), with particular emphasis on their deterministic coupling to optical cavities and to QPIC platforms. I will discuss the key technological steps required to realise efficient and scalable QD-based photon sources. These include controlling QD density and emission wavelength during epitaxial growth, improving photon extraction using metallic and distributed Bragg reflector structures, designing cavities for out-of-plane and in-plane photon collection, and implementing electric-field control of QD emission wavelength and charge state. I will also describe hyperspectral imaging methods for locating suitable emitters and enabling accurate QD–cavity alignment, as well as chip-transfer approaches for hybrid integration of cavity-coupled QD devices with SiN and SiO₂/Si photonic platforms. The seminar will highlight how this work combines QPIC design using foundry-compatible process design kits, metalorganic vapour phase epitaxy, precision nanofabrication, near-infrared optical microscopy, optical modelling, and linear and quantum photonic experiments. Together, these tools provide a route towards scalable, QD-based telecom-compatible quantum light sources for integrated quantum photonics. Y. Berdnikov et al. Fine-tunable near-critical Stranski-Krastanov growth of InAs/InP quantum dots, Scientific Reports 14, 23697 (2024). P. Holewa et al. Bright Quantum Dot Single-Photon Emitters at Telecom Bands Heterogeneously Integrated on Si, ACS Photonics 9, 7 (2022). P. Holewa et al. High-throughput quantum photonic devices emitting indistinguishable photons in the telecom C-band, Nature Communications 15, 3358 (2024). M. G. Mikulicz et al. InAs/InP quantum dot based C-Band all-fiber plug-and-play triggered single-photon source integrated using micro-transfer printing, Physical Review Applied 24, 014023 (2025). P. Mrowiński et al. Optimization of heterogeneously integrated InP-Si on-chip photonic components, Optics Express 31, 1541 (2023).