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An imaging supercurrent distribution technique in high-temperature superconducting thin film devices is presented. The methodology, which uses photoexcited THz radiation, obtains the images by scanning focused femtosecond laser pulses on the superconducting film devices while in the process of detecting the THz radiation. The Bean critical state model is used to interpret the distribution of the obtained transport and persisting currents.

Research was conducted to examine the optical creation and modulation of magnetic flux quanta in a YBa2Cu3O(70delta) thin film loop by observing terahertz emission excited with femtosecond laser pulses. The mechanism of the optical creation of the magnetic flux in the loop was also investigated. Results indicate a possible application of the superconductive loop as an optical flux-trap memory for the detection and storage of the femtosecond optical signals.

A novel method to investigate the superconductivity of YBCO thin films damaged by ion beam processing is presented using the time-resolved reflection pump-probe method in the femtosecond time region. Findings suggest that the ion beam processing affects the change of the amplitude and the relaxation time of the reflectivity produced by the optical pulse excitation. Thus, the method can be used in evaluating superconductivity in the surface region.

Makes observations on the supercurrent distribution in YBa[sub 2]Cu[sub 3]O[sub 7-delta] thin films using terahertz radiation excited with femtosecond laser pulses. Characteristics of the transport current distribution; Comparison of current density calculated and measured values; Transition temperature; Film thickness.