Spatiotemporally tunable dark/bright and weak/strong mode coupling in all-dielectric DBR-metasurface-DBR structures

We report spatiotemporally tunable mode coupling between Fabry-Pérot (F-P) resonances and dark or bright modes in the weak- or strong-coupling regime in an all-dielectric coupled system, which consists of an F-P microcavity formed by two distributed Bragg reflectors (DBR) and a metasurface made of periodic nanocavities. Simulation results show that F-P resonances can be tuned to be coupled to dark waveguide modes or a bright electric dipole Mie surface lattice resonance, depending on the microcavity height, and that the coupling strength can be manipulated between the weak- and strong-coupling regimes by varying the photon lifetime, or equivalently the quality factors (Q-factors) of F-P resonances, which can be realized by changing the number of DBR layers. We also show that the slow-light effect associated with the electromagnetically induced reflection-like window in the weak-coupling regime can also be regulated through the Q-factor. With all these findings, our study provides an alternative for manipulating light-matter interactions in coupled micro-/nano-cavities that are promising for various applications.