Characteristics of terahertz radiation emitted from the intrinsic Josephson junctions in high-Tc superconductor Bi2Sr2CaCu2O8+δ

Characteristic features of terahertz radiation emitted from a rectangular mesa comprised stacked intrinsic Josephson junctions in the layered high-T-c superconductor Bi2Sr2CaCu2O8+delta are reported. The emission with the total power of similar to 5 mu W at 0.63 THz shows a characteristic spatial distribution reflecting the rectangular shape. The stability of the emission was measured for at least 20 min. and the power fluctuation was found to be less than 4%. Furthermore, the radiation is highly polarized linearly with a ratio of 50:1. All features, including the spectral purity narrower than 4 GHz at full width at half maximum, promise a stable, coherent, and continuous terahertz source for various applications. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3269996]