A method and device which can receive and identify electromagnetic radiation in the terahertz (THz) frequency range. The device has a combination of material and geometric parameters that are unique and tunable, enabling resonating frequencies for spectral selectivity in the THz range (0.1-15) with ultra-narrow channel widths (0.01-0.10 THz) full width at half maximum (FWHM). Dependent upon configuration, the device may be employed as a large area resonator to collect weak or diffuse signals or as a constituent of an array able to take pictures within the spectrum for which they are sensitive.