Direct imaging and dynamic control of temperature distributions in superconducting terahertz sources for intense terahertz emission

Terahertz-frequency light has recently attracted interest across many fields, including biology and medical diagnostics, security and nondestructive inspection. Synchronized stacks of superconducting Josephson junctions provide a high-intensity potential source of terahertz radiation; however, designing powerful sources requires a strategy to overcome local overheating that destroys the superconducting property. The authors here find that hot spots can be minimized in these devices, thus substantially increasing the intensity of resulting coherent terahertz waves.