Structural Engineering in Plasmon Nanolasers

This review focuses on structural engineering of lasers from the macroscale to the nanoscale, with an emphasis on plasmon nanolasers. Conventional lasers based on Fabry–Pérot cavities are limited in device size. In contrast, plasmon nanolasers can overcome the diffraction limit of light and incorporate unique structural designs to engineer cavity geometries and optical band structure. Since the spaser concept was introduced in 2003, tremendous progress in nanolasing has been made on architectures that exploit metal films and nanoparticles. Theoretical approaches in both frequency and time domains have inspired the development of plasmon nanolasers based on mode analysis and time-dependent lasing buildup. Plasmon nanolasers designed by band-structure engineering open prospects for manipulation of lasing characteristics such as directional emission, real-time tunable wavelengths, and controlled multimode lasing.