Broadband efficient light absorbing in the visible regime by a metananoring array

The broadband efficient light-absorbing property of a metamaterial-based subwavelength nanoring array in visible regime is reported. The nanoring array can absorb light efficiently with an average absorptivity of 0.97 over the whole visible waveband. In addition, it is found that this kind of super light-absorbing capability is independent of the incoming light polarization state and can maintain an average of 0.9 for an incident angle as large as 60 degrees under TM illumination. The perfect absorbing property of the metamaterial-based nanoring array is attributed to the synergetic effect of the Fabry-Perot resonance and the localized surface plasmon resonance enhancement.