A nanoscale YBCO mixer optically coupled with a bow tie antenna

The bolometric response of YBa2Cu3O7-delta(YBCO) hot-electron bolometers (HEBs) to near-infrared radiation was studied. Devices were fabricated from a 50 nm thick film and had in-plane areas of 10 x 10 mu m(2), 2 x 0.2 mu m(2), 1 x 0.2 mu m(2) and 0.5 x 0.2 mu m(2). We found that nonequilibrium phonons cool down more effectively for the bolometers with smaller area. For the smallest bolometer the bolometric component in the response is 10 dB less than for the largest one.