A terahertz electron-phonon integrated bolometer

We have developed a novel electron-phonon bolometer for sensitive detection of terahertz radiation. The electron gas in a nano-scale normal metal forms the absorber element of our bolometer. Owing to the weak thermal coupling between the electron gas and phonon bath in normal metals at low temperatures extraordinarily small thermal conductances are possible. The temperature of the normal metal absorber was measured using superconducting - insulating - normal metal tunnel junctions whose electrical conductance is exponentially sensitive to changes in the electron temperature. Terahertz radiation was generated using a blackbody source and focused to the absorber using a 1 THz twin slot antenna.;The integrated thermometry allowed the electron-phonon dynamics to be probed and described according to existing models. Illumination with terahertz radiation allowed the device response as an antenna coupled bolometer to be measured. Ultimately this technology is intended for large arrays with single photon detection capabilities. To that end the bolometer was characterized using radio-frequency measurements. We demonstrate at radio-frequencies a noise equivalent power which is competitive with existing technology.