Fabrication of an infrared bolometer with a high Tc superconducting thermometer

A sensitive high (Tc) superconducting bolometer was fabricated on a 20 micron thick sapphire substrate with a YBCO thin film transition edge thermometer. Optical measurements with a He-Ne laser gave a noise equivalent power of 2.4 x 10(exp -11) W/Hz(exp 1/2) at 10 Hz and a responsivity of 17 V/W in good agreement with electrical bolometer measurements. Gold black smoke was then deposited on the back side of the assembled bolometer as an absorber. Spectral measurements on a Fourier transform spectrometer show that the bolometer has useful sensitivity from visible wavelengths to beyond approx. 100 microns. This performance is clearly superior to that of a commercial room temperature pyroelectric detector. Some improvement appears possible.