Measurement of local reactive and resistive photoresponse of a superconducting microwave device

We propose and demonstrate a spatial partition method for the high-frequency photoresponse of superconducting devices correlated with inductive and resistive changes in microwave impedance. Using a laser scanning microscope, we show that resistive photoresponse is mainly produced by local defects at microstrip edges and by intergrain weak links formed in the high-temperature superconducting material at the boundary between individual twin-domain blocks. These defects are known to initiate nonlinear high-frequency response.