Ultrahigh frequency measurements of magnetic penetration length and surface impedance of YBa₂Cu₃O_7-x microstriplines on Si and GaAs substrates

Superconducting microstriplines of YBa₂Cu₃O _7-x have been deposited and patterned on substrates of silicon on sapphire and GaAs. In both substrates fast semiconducting photoswitches were fabricated and integrated into the microstriplines. Short lightpulses of 100 fs length generated electrical pulses in the semiconducting photoswitches. The electrical pulses were launched into the superconducting striplines, where they were detected by electro-optical sampling. This method permits the analysis of the frequency dependence of the YBa₂Cu₃O_7-x surface impedance Z_s(T,ν) and the magnetic penetration depth λ(T,ν) in the temperature regime 10≤T≤90 K and the frequency range 10 GHz≤ν≤600 GHz. The Z_s and λ measurements showed that the electrical data of the YBa₂Cu₃O _7-x were comparable to those of YBa₂Cu₃O _7-x deposited on LaAlO₃.