https://doi.org/10.1051/epjconf/202328705002
Strong Er3+ radiative emission enhancement by quasi-BIC modes coupling in all-dielectric slot nanoantenna arrays
1 Department of Physics and Astronomy, University of Padova, Via Marzolo 8, I-35131 Padova, Italy
2 The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2BW, United Kingdom
* e-mail: boris.kalinic@unipd.it
Published online: 18 October 2023
We have designed and realized all-dielectric lossless nanoantennas, in which a thin SiO2 layer doped with erbium ions is placed inside slotted silicon nanopillars arranged in a square array. The modal analysis has evi-denced that the slotted nanopillar array supports optical quasi-BIC resonances with ultra-high Q-factors (up to Q∼109), able to boost the electromagnetic local density of optical states in the optically active layer. Up to 3 orders of magnitude photoluminescence intensity increment and 2 orders of magnitude decay rate enhancement have been measured at room temperature when the Er3+ emission at about λ=1540 nm couples with the quasi-BIC resonances. Furthermore, by tailoring the nanopillar aspect ratio, the slot geometry has been exploited to obtain selective enhancements of the electric or magnetic dipole contribution to Er3+ radiative transitions in the NIR, keeping the emitter quantum efficiency almost unitary. Finally, by computing the angularly resolved elec-tromagnetic field enhancement inside the nanoslot, the nanoantenna directivity has been designed, proving that strong beaming effects can be obtained. Our findings have a direct impact on the development of bright and effi-cient photon sources operating at telecom wavelength that are of primary importance for quantum nanophotonic applications.
© The Authors, published by EDP Sciences, 2023
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
