Modulated optical reflectance characterization of high temperature superconducting thin film microwave devices

The modulated optical reflectance (MOR) technique is shown to provide a roo m temperature, noncontact, nondestructive and high spatial resolution means of assessing high temperature superconducting (HTS) thin film quality. Roo m temperature MOR characterizations of a number of 8 GHz planar HTS resonat ors indicating a range of property variations and local degradations in HTS film performance are shown to be consistent with results obtained at low t emperatures by the electron beam induced voltage contrast technique. The mi crowave performances of some of the resonators are found to exhibit nonline ar characteristics that can be explained by HTS defects revealed by the MOR technique. (C) 2000 American Institute of Physics. [S0021-8979(00)06711-6] .