Dual-channel spontaneous emission enhancement metasurfaces in the mid-infrared based on an anapole state.

Controlling spontaneous emission from electric dipole (ED) and magnetic dipole (MD) is crucial for quantum light sources, molecular sensing, and integrated quantum photonics. Enhancing these processes relies on intense local fields to boost the local density of optical states (LDOS). While conventional plasmonic structures provide strong fields, their performance is severely limited by inherent ohmic losses. We designed and experimentally verified a germanium-based metasurface exciting a nonradiative anapole state to overcome this limitation. This approach generates extreme near-field confinement, significantly strengthening light-matter interactions. We numerically demonstrate a dual-channel platform simultaneously accelerating ED and MD emissions at spatially distinct hot spots, reaching Purcell factors (PFs) of 6057 and 2272, respectively. The quality factor, field enhancement, and PF of the resonator are precisely tunable by adjusting its geometric parameters. This work provides a platform for dual-dipole emission engineering, paving the way for high-performance quantum light sources, molecular fingerprinting, and on-chip quantum devices in the mid-infrared.