Phys.org June 11, 2020 Plasmonic lasers suffer from low output power and divergent beams due to their subwavelength metallic cavities. A team of researchers in the US (Leigh University, Sandia National Laboratory) longitudinally coupled an array of metallic microcavities through traveling plasmon waves which led to radiation in a single spectral mode and a diffraction limited single-lobed beam in the surface normal direction. They implemented the scheme for terahertz plasmonic quantum-cascade lasers and measured peak output power in excess of 2W for a single-mode 3.3THz QCL radiating in a narrow single-lobed beam, when operated at 58K in a compact Stirling […]