Wavelength dependent photoresponse in YBCO thin-film systems

We present results on the 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 /spl mu/m and at frequencies from 3 to 10/sup 5/ Hz at 0.670 /spl mu/m. The response was bolometric in nature in the vicinity of T/sub c/ (R=30 V/W). However, the response below T/sub c/ shows significant enhancement at 0.670 /spl mu/m. The wavelength regime of the enhancement suggests the participation of transient photodoping of the material or related phenomena.