Powerful terahertz emission from Bi2Sr2CaCu2O8+δ mesa arrays

Stacks of intrinsic Josephson junctions in high-temperature superconductors enable the fabrication of compact sources of coherent terahertz radiation. Here, we demonstrate that multiple stacks patterned on the same Bi2Sr2CaCu2O8+delta crystal can-under optimized conditions-be synchronized to emit high-power THz-radiation. For three synchronized stacks, we achieved 610 mu W of continuous-wave coherent radiation power at 0.51 THz. We suggest that synchronization is promoted by THz-waves in the base crystal. We note that synchronization cannot be achieved in all samples. However even in these cases, powers on the 100-mu W scale can be generated. (C) 2013 AIP Publishing LLC.