Ｍiddle to far infrared characteristics of high temperaturesuperconductive YBCO thin film illuminated with BFEL

A middle to far infrared detector, which uses a YBCO high temperature superconductive thin film, is introduced in the paper. The research on its middle to far infrared response characteristics is conducted by utilizing the Beijing Free Electronic Laser. The microbridge size of the test target is 210μm×70μm×0.3μm and its voltage, spectrum, and time responses are measured. Results show that the YBCO high temperature superconductive light detector, which works under the temperature of liquid nitrogen, has properties of fast response ,high sensibility, good wide bandwidth and good stability.