Coplanar Plasmonic Nanolasers Based on Edge-Coupled Hybrid Plasmonic Waveguides

A novel type of coplanar plasmonic laser based on an edge-coupled hybrid plasmonic waveguide is proposed and analyzed theoretically. This structure enables the realization of an air gap between the nanowire and the metal layer that could facilitate enhanced field confinement. By simulating the modal properties and the lasing threshold under different geometric parameters, it is demonstrated that with smaller gap widths and metal films of a larger rounded-corner radius, the lasing threshold could be reduced significantly. The structure could enable deep-subwavelength lasing with low pump thresholds and be readily integrated with other plasmonic structures for future coplanar active plasmonic circuits.