Design of a dual-layer concentric-ring metalens with switchable unidirectional fluorescence emission based on deep reinforcement learning
Phys. Rev. Applied 25, 014013 – Published 7 January, 2026
DOI: https://doi.org/10.1103/rbq5-4yy1
Abstract
Controlling the directional emission of quantum dots (QDs) is essential for applications in lighting, optical communications, biomedicine, and quantum information technologies. However, most existing strategies fail to simultaneously achieve high directionality and strong emission efficiency. Here, we present a dual-layer concentric-ring metalens optimized through inverse design powered by a deep reinforcement learning algorithm. This approach not only boosts fluorescence and directional emission but also significantly reduces the computational overhead. The proposed structure enables nonreciprocal emission control of embedded QDs, driven by unique near-field coupling and constructive interference of Bloch surface waves. A fluorescence enhancement factor of up to 5371 is achieved, with an emission divergence angle below 5°. Moreover, both the emission wavelength and directionality are tunable by varying the thickness ratio of dual-layer concentric-ring or the QD position. These findings offer promising opportunities for integrated quantum light sources and advanced biomedical photonic systems.
