A metamaterial-coupled hot-electron-bolometer working at THz frequencies

We will report our recent results using ultrathin NbN films (4-5 nm) for developing both conventional antenna-coupled hot-electron-bolometers (AC-HEBs) and of a novel type of phonon cooled HEB electrically-coupled to a metamaterial acting as a resonant absorber at THz frequencies (MM-HEB), optically-coupled through arrays of split ring resonators (metadevices). In a phonon-cooled HEB, being the active layer an ultrathin film of superconducting NbN, we have an ultrafast thermal direct detector that is also frequency selective thanks to the integration with the resonant metamaterial. We characterized both the AC-HEB and the MM-HEB by electro optical measurements using as a sources both the black body emission and terahertz quantum cascade lasers (THz-QCLs) and we compared their performances.