Strong visible magnetic resonance of size-controlled silicon-nanoblock metasurfaces

To extend the operating window of all-dielectric metamaterials into the visible regime, obtaining controllable magnetic resonance is essential. We experimentally demonstrated strong magnetic resonance at 595 nm using an array of amorphous silicon (a-Si) nanoblocks. The results of both theoretical calculations and experiments show that magnetic resonance can be tuned continuously by appropriately varying the size and thickness of a-Si nanoblocks. We also experimentally achieved a magnetic resonance Q-factor of ∼10, which is a higher value than that yielded by a metallic split-ring resonator in the visible regime.