A simple high-temperature superconducting thin-film optical bolometer

The authors have demonstrated the operation of a simple optical bolometer by irradiating a constriction in a Y1Ba2Cu3O7-δ thin film with chopped laser light at λ=633 nm. The change in film resistivity was measured by lock-in detection of the AC component in the current-biased mode. Operating optimally near 77 K, the bolometer shows detectivity of 5 mV W-1 and NEP of 10-6 W Hz-1/2. The authors discuss the possibility of methods to improve these figures by at least three orders of magnitud