Resonant Light Trapping via Lattice-Induced Multipole Coupling in Symmetrical Metasurfaces

We demonstrate a general multipole mechanism of the resonant mode trapping effect in metasurfaces composed of MoS₂disk-shaped nanoresonators. The implementation of this mechanism does not require any special irradiation conditions for the incident light or geometrical distortion of the symmetry of the metasurface translation unit cell. It is established that the effect arises due to the periodic-lattice-induced coupling between the electric dipole and electric octupole modes existing in the nanoresonators. We show that, under these conditions, the resonant quasi-trapped octupole mode and the suppression of the electric dipole response can be self-consistently realized under the action of normally incident plane waves. This, in turn, leads to the appearance of a narrow-band-induced transparency of the metasurface supplemented by the strong electromagnetic energy storage in the nanoresonators. Due to its general nature, the presented mechanism can be implemented in various dielectric and semiconductor metasurfaces, whose meta-atoms support resonant excitation conditions for different-order multipole moments with the same inverse symmetry property.