Highly correlated photon sources can be realized through cooperative coupling among quantum systems, giving rise to superradiant collective emission. In solid-state ensembles, however, such collective behaviour is confined to subwavelength dimensions and is strongly suppressed at room temperature by inhomogeneous broadening and rapid dephasing, limiting practical implementations. Here, we show that molecular J-aggregates sustain room temperature superradiant emission and enter a highly collective regime when strongly coupled to delocalized photonic modes of a silicon bound-state-in-the-continuum (BIC) metasurface, extending J-exciton interactions far beyond the subwavelength limit. This enhanced cooperativity produces a Rabi-splitting-dependent increase in emission rate and intensity and drives the system into a highly superbunched photon emission regime with g(2)(0)>13. Stochastic modelling reveals that metasurface-mediated synchronization of ~10^3 J-excitons occurs within coupled superradiant domains spanning up to 8.5 um in diameter, corresponding to a 50-fold increase in inter-aggregate cooperative distance. These results establish common-mode coupling in resonant dielectric metasurfaces as a scalable route for engineering ultrafast, temporally correlated light sources operating at room temperature.
Categories: physics.app-ph