Wavelength dependent photoresponse in YBCO thin-film systems

We present results on the structures photoresponse of YBCO narrow-line structures with deliberately broadened resistive transitions. We have explored the photoresponse of these systems as a function of temperature, bias current and power at wavelengths of 0.670, 0.850 and 10.6 mu m and at frequencies from 3 to 10(5) Hz at 0.670 mu m. The response was bolometric in nature in the vicinity of T-c (R similar to 30V/W). However, the response below T-c shows significant enhancement at 0.670 mu m, The wavelength regime of the enhancement suggests the participation of transient photodoping of the material or related phenomena.