Semiconductor quantum dots (QDs) grown by molecular beam epitaxy are excellent quantum emitters, but their random spatial distribution hinders deterministic coupling to optical microcavities. We demonstrate a room-temperature atomic force microscopy (AFM)-assisted nano-oxidation lithography technique enabling QD positioning with a radial displacement of 51(28) nm. Free-standing asymmetric circular Bragg gratings incorporating AFM-positioned GaAs QDs exhibit a 245-fold photoluminescence enhancement and fine-structure splitting (FSS) comparable to bulk QDs. Polarization-resolved spectroscopy and finite-difference time-domain simulations show robust emission for displacements up to 50 nm (Stokes parameter ∣S∣<0.05 ). The devices display stable FSS and polarization imbalance below 5% , confirming precise, reproducible alignment and potential for high fidelity devices. This scalable approach enables deterministic integration of high-performance QDs with photonic cavities, advancing practical quantum light sources for quantum information technologies.
@article{arxiv.2605.03672,
title = {Deterministic positioning of circular Bragg gratings using atomic force lithography for high-performance quantum dot light sources},
author = {Sai Abhishikth Dhurjati and Moritz Langer and Yared G. Zena and Ahmad Rahimi and Liesa Raith and Martin Bauer and Frank H. P. Fitzek and Riccardo Bassoli and Caspar Hopfmann},
journal= {arXiv preprint arXiv:2605.03672},
year = {2026}
}