Continuous and reversible electrical-tuning of fluorescent decay rate via Fano resonance

Abstract We demonstrate electrically tunable control of the radiative and nonradiative decay rates of a fluorescent molecule through a Fano-resonant transparency embedded in the plasmonic local density of optical states (LDOSs). An auxiliary quantum object (QO) placed at the hotspot of a plasmonic nanoparticle suppresses the plasmonic excitation at its transition frequency {ω}_QO , thereby creating a narrow transparency window and reducing the LDOS at ω={ω}_QO . When the fluorescence frequency of a nearby emitter overlaps this window, the plasmon-induced enhancement of both radiative and nonradiative decay is strongly suppressed. Because {ω}_QO can be shifted electrically, the transparency can be moved reversibly across the fluorescence line, enabling continuous voltage control of the decay rates. Three-dimensional Maxwell simulations predict tuning of the radiative and nonradiative channels by up to two orders of magnitude. The proposed mechanism offers a compact route toward fast, reversible control of light–matter interaction in integrated photonics, with potential applications in single-photon sources, electrically programmable quantum devices, super-resolution microscopy, and surface-enhanced Raman spectroscopy.