A Single-Emitter Gain Medium for Bright Coherent Radiation from a Plasmonic Nanoresonator

We propose and demonstrate theoretically bright coherent radiation from a plasmonic nanoresonator powered by a single three-level quantum emitter. By introducing a dual-pump scheme in a Raman configuration for the three-level system, we overcome the fast decay of nanoplasmons and achieve macroscopic accumulation of nanoplasmons on the plasmonic nanoresonator for stimulated emission. We utilize the optical antenna effect for efficient radiation of the nanoplasmons and predict photon emission rates of 100 THz with up to 10 ps duration pulses and GHz repetition rates with the consideration of possible heating issue. We show that the ultrafast nature of the nanoscopic coherent source allows for operation with solid-state emitters at room temperature in the presence of fast dephasing. We provide physical interpretations of the results and discuss their realization and implications for ultracompact integration of optoelectronics.