Investigation of photoresponse in Y-Ba-Cu-O epitaxial films

We have studied the photoresponse of YBCO epitaxial thin films to optical irradiation at wavelength of 0.6328 /spl mu/m. The dependence of the optical response on bias electric current, temperature and frequency has been measured. These results suggest that bolometric and nonbolometric components exist at temperatures below the transition temperature. The total response is proportional to the dynamic resistance, quasiparticle, and flux flow.