Development of a new Superconducting Submillimeter Wave Oscillator

本研究的目的是研制一种用于测量亚毫米波的新型超导振荡器。在本研究中，我们获得了以下结果：1.磁通流振荡器(FFO)的性能评价我们利用NbN/Pb约瑟夫森结和Nb/Al/Nb约瑟夫森结成功地观测到了100 GHz到1500 GHz频率范围内的振荡特性。利用前一个结，我们证明了在带状线上可以产生1-3 mA的电流。2.电感耦合阻抗匹配电路的研制仿真结果表明，利用双谐振效应可以实现宽带匹配电路。利用该设计制作了NbN/Pb约瑟夫森结FFO和NbN/Nb_2O_5/Nb带状线，并成功地验证了电感耦合方法的有效性。

The prupose of this research is to develop a new superconducting oscillator for measuring submillimeter waves. In this research we obtained the following results:1.Evaluation of the Performance of the Flux-Flow Oscillator(FFO)We succeeded in the observation of the oscillation characteristics in the frequency range between 100GHz and 1500GHz using NbN/Pb Josephson junctions and Nb/Al/Nb Josephson junctions. Using the former junction we showed that the currents of 1-3 mA can be induced in the striplines. Using the latter junction we succeeded in obtaining oscillation output at frequencies more than 1THz.2.Development of Impedance Matching Circuit with Inductive Coupling MethodWe showed by simulation that broad band matching circuits can be realized using double resonance effects. Using this design we fabricated an FFO using NbN/Pb Josephson junction and a stripline made of NbN/Nb_2O_5/Nb,and succeed in demonstrating the validity of the inductive coupling method.