Abstract
We demonstrate the spectral control of thermal radiation by a metamaterial with a split-ring resonator (SRR). We experimentally observe the resonant enhancement of thermal radiation from an SRR array at specific wavelengths. The measured peaks of relative emittance are in good agreement with numerical simulations. These peaks are controlled by the size of the SRR. The thermal radiation source constituted by the metasurface can be applied to a thin-film emitter from terahertz to visible frequency.