Microwave Superconducting Circuit Current Of The Laser-assisted Measurement

High Temperature Superconducting Microwave devices which are developed with superconducting and microwave technology have predominant performances than normal metal microwave devices with high sensitivity, low noise and interference. However applied high-temperature superconducting material will produce the non-linear effects in the low, middle and high microwave field. Such characteristics affect the performances of superconducting microwave circuits, on the other hand it provides an opportunity for the development of new superconducting microwave devices. Despite the academic proposed several different theories of representation about the nonlinear high-temperature superconducting materials of by macro measurement, but there isn't any theory can explain all phenomenons. Local measurement methods are needed to explore its mechanism further.In this paper, microwave superconducting circuits current distribution analysis experiment has been completed using laser aided measurement which is local measurement based on the linear & nonlinear model of superconducting materials and photo-induced superconductivity nonlinear theory. In this experiment, internal current distribution has been measured and analyzed through high temperature superconductor micro-bridge resonator irradiated by laser. The theory is as follows: When the same laser irradiate at high temperature superconducting micro-bridge resonator, different intensity current part will produce different intensity of non-linear, and this nonlinearity can be directly indicated by the measurement of the third-order intermodulation signal (IMD3). Therefore high temperature superconducting micro-bridge resonator current distribution can be induced by moving the laser irradiation position and tested the microwave signal third order intermodulation performance.The experiment result that compared to conventional non-linear measurement, laser aided measurement of high-temperature microwave superconducting circuits is a local measurement, and it is great important on high temperature superconducting materials'microwave nonlinear mechanism. It has great significance not only for the research of passive components based on high temperature superconducting materials' microwave nonlinear mechanism, such as high-temperature superconducting microwave limiter, high-temperature superconducting microwave switch, but also for the manufacture of high-temperature superconducting microwave active devices based on Josephson effect. The relevent papers about measuring micro-birdge microwave resonator with laser are not reported.