Abstract
Plasmonic nanolasers (PNLs) have attracted much attention in recent years due to their light-trapping capabilities beyond the diffraction limit. However, the physics that underpins the lasing action in such devices has not received sufficient treatment in the literature. The contribution of plasmons in PNLs needs to be understood at a granular level for designing enhanced nanoscopic lasers. In this work, we present a modal decomposition-based analysis of a planar PNL that employs a two-dimensional metallic nanohole array interfaced with the gain medium. Using state-of-the-art simulation techniques, we isolate the plasmonic mode that emerges at the metal-gain medium interface interlaced with scattering modes. We present a step-bystep dispersion analysis to identify the possible modes supported by the planar PNL structure and locate the operating point of the PNL. Furthermore, we show how the plasmonic mode regulates the lasing action, and hence, can serve as a tool for laser tunability.