Continuous wave terahertz radiation above 1 THz from Josephson junction arrays

In recent years coherent terahertz (THz) radiation from stacks containing nearly 1000 Bi₂Sr₂CaCu₂O₈ (BSCCO) intrinsic Josephson junctions (IJJs) has attracted a lot of research interest. However, in most cases, reported have been frequencies well below 1 THz, or typically around 500 GHz, which obviously can be a bottleneck for many applications. In our experiments, by optimizing sample structures and material doping levels, we successfully observed THz radiation at fundamental frequencies above 1 THz. Reported at the conference will be the fabrication process, 600 GHz tunability, and other latest experimental results.