High-power terahertz electromagnetic wave emission from high-T(c) superconducting Bi2Sr2CaCu2O(8+δ) mesa structures.

In this paper, we report intense electromagnetic wave emissions generated by the rectangular mesa structure of intrinsic Josephson junctions with high-T(c) superconducting Bi2Sr2CaCu2O(8+δ). The radiated power is an order of magnitude stronger than that of the previously observed power of a few μW. Two emission regions, reversible (R-type) and irreversible (IR-type), with comparable intensities can be observed at different I-V curve locations in the same mesa.

Geometrical resonance conditions for THz radiation from the intrinsic Josephson junctions in Bi(2)Sr(2)CaCu(2)O(8+δ).

Subterahertz radiation emitted from a variety of short rectangular-, square-, and disk-shaped mesas of intrinsic Josephson junctions fabricated from a Bi(2)Sr(2)CaCu(2)O(8+δ) single crystal was studied from the observed I-V characteristics, far-infrared spectra, and spatial radiation patterns. In all cases, the radiation frequency satisfies the conditions both for the ac Josephson effect and for a mesa cavity resonance mode. The integer higher harmonics observed in all spectra imply that the ac Josephson effect plays the dominant role in the novel dual-source radiation mechanism.