Mimicking plasmonic nanolaser emission by selective extraction of electromagnetic near-field from photonic microcavity.

Plasmonic nanolasers have attracted significant attention owing to their ability to generate a coherent optical field in the deep subwavelength region, and they exhibit promising applications in integrated photonics, bioimaging and sensing. However, the demonstration of lasing in individual metallic nanoparticles with 3D subwavelength confinement represents a significant challenge and is yet to be realized. Herein, we propose to mimic a plasmonic nanolaser via selective scattering off the evanescent tail of a lasing photonic nanobelt using a single silver nanorod (24 nm × 223 nm). The nanorod acts as an optical antenna that selectively extracts the near-field component along the rod axis. The light output from the silver nanorod mimics the emission of a plasmonic nanolaser in its localized near-field and polarization dependence, except for the lasing wavelength and linewidth, which are inherited from the photonic laser. The realization of localized coherent light sources provides promising nanoscale lighting that shows potential in background-suppressed illumination, biosensing and imaging.