Development of ultrafast optical interfaces for single flux quantum devices

用电压自相关技术测量了飞秒激光在约瑟夫森结(JJ)和超导桥(SBS)中产生的时间分辨率为亚皮秒的电压脉冲。结果表明，在JJS和SBS中，我们可以观察到光生电压的快分量和慢分量，它们分别短于几皮秒和长于几纳秒。搭建了一台扫描激光磁光显微镜，可以观察到单磁通量子的调制。

Voltage pulses generated in the Josephson junctions (JJs) and superconductor bridges (SBs) by the irradiation of femtosecond laser pulses were measured with sub-picosecond time resolution using a voltage autocorrelation technique. As a result, we could observe fast and slow components of photo-induced voltages, which are shorter than several picoseconds and longer than several nanoseconds respectively, with JJs and SBs. A scanning laser magneto-optical microscope has been constructed and the modulation of single flux quantum could be observed.