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Photonic Jet Writing of Quantum Dots Self‐Aligned to Dielectric Microspheres
Author(s) -
Ristori Andrea,
Hamilton Travis,
Toliopoulos Dimosthenis,
Felici Marco,
Pettinari Giorgio,
Sanguinetti Stefano,
Gurioli Massimo,
Mohseni Hooman,
Biccari Francesco
Publication year - 2021
Publication title -
advanced quantum technologies
Language(s) - English
Resource type - Journals
ISSN - 2511-9044
DOI - 10.1002/qute.202100045
Subject(s) - quantum dot , materials science , photonics , optoelectronics , dielectric , fabrication , laser , photon , refractive index , semiconductor , nanotechnology , optics , physics , medicine , alternative medicine , pathology
Owing to their ability to generate non‐classical light states, quantum dots (QDs) are very promising candidates for the large‐scale implementation of quantum information technologies. However, the high photon collection efficiency demanded by these technologies may be impossible to reach for “standalone” semiconductor QDs, embedded in a high‐refractive index medium. In this work a novel laser writing technique is presented, enabling the direct fabrication of a QD self‐aligned—with a precision of ±30 nm—to a dielectric microsphere. The presence of the microsphere leads to an enhancement of the QD luminescence collection by a factor 7.3 ± 0.7 when an objective with 0.7 numerical aperture is employed. This technique exploits the possibility of breaking the N−H bonds in GaAs1 − x N x :H by a laser light, obtaining a lower‐bandgap material, GaAs1 − x N x . The microsphere, deposited on top of a GaAs1 − x N x :H/GaAs quantum well, is used to generate a photonic nanojet, which removes hydrogen exactly below the microsphere, creating a GaAs1 − x N x QD at a predefined distance from the sample surface. Second‐order autocorrelation measurements confirm the ability of the QDs obtained with this technique to emit single photons.