biostudies-literatureUnknown10(2)Kalinic BIn the quest for new and increasingly efficient photon sources, the engineering of the photonic environment at the subwavelength scale is fundamental for controlling the properties of quantum emitters. A high refractive index particle can be exploited to enhance the optical properties of nearby emitters without decreasing their quantum efficiency, but the relatively modest <i>Q</i>-factors (<i>Q</i> ∼ 5-10) limit the local density of optical states (LDOS) amplification achievable. On the other hand, ultrahigh <i>Q</i>-factors (up to <i>Q</i> ∼ 10⁹) have been reported for quasi-BIC modes in all-dielectric nanostructures. In the present work, we demonstrate that the combination of quasi-BIC modes with high spectral confinement and nanogaps with spacial confinement in silicon slotted nanoantennas lead to a significant boosting of the electromagnetic LDOS in the optically active region of the nanoantenna array. We observe an enhancement of up to 3 orders of magnitude in the photoluminescence intensity and 2 orders of magnitude in the decay rate of the Er³⁺ emission at room temperature and telecom wavelengths. Moreover, the nanoantenna directivity is increased, proving that strong beaming effects can be obtained when the emitted radiation couples to the high <i>Q</i>-factor modes. Finally, via tuning the nanoanntenna aspect ratio, a selective control of the Er³⁺ electric and magnetic radiative transitions can be obtained, keeping the quantum efficiency almost unitary.ACS photonics534-543https://www.ebi.ac.uk/biostudies/studies/S-EPMC9936627biostudies-literatureQuasi-BIC Modes in All-Dielectric Slotted Nanoantennas for Enhanced Er³⁺ Emission.PMC9936627Balasa IGMattei GJacassi ASapienza RMaier SAKalinic BCesca TTrevisani MfalseQuasi-BIC Modes in All-Dielectric Slotted Nanoantennas for Enhanced Er³⁺ Emission.In the quest for new and increasingly efficient photon sources, the engineering of the photonic environment at the subwavelength scale is fundamental for controlling the properties of quantum emitters. A high refractive index particle can be exploited to enhance the optical properties of nearby emitters without decreasing their quantum efficiency, but the relatively modest <i>Q</i>-factors (<i>Q</i> ∼ 5-10) limit the local density of optical states (LDOS) amplification achievable. On the other hand, ultrahigh <i>Q</i>-factors (up to <i>Q</i> ∼ 10⁹) have been reported for quasi-BIC modes in all-dielectric nanostructures. In the present work, we demonstrate that the combination of quasi-BIC modes with high spectral confinement and nanogaps with spacial confinement in silicon slotted nanoantennas lead to a significant boosting of the electromagnetic LDOS in the optically active region of the nanoantenna array. We observe an enhancement of up to 3 orders of magnitude in the photoluminescence intensity and 2 orders of magnitude in the decay rate of the Er³⁺ emission at room temperature and telecom wavelengths. Moreover, the nanoantenna directivity is increased, proving that strong beaming effects can be obtained when the emitted radiation couples to the high <i>Q</i>-factor modes. Finally, via tuning the nanoanntenna aspect ratio, a selective control of the Er³⁺ electric and magnetic radiative transitions can be obtained, keeping the quantum efficiency almost unitary.2023-01-01T00:00:00Z2023 Feb2025-04-04T13:36:36.464Z2025-04-04T13:36:36.464ZS-EPMC99366273682032410.1021/acsphotonics.2c01703