title: Low-threshold plasmonic lasing based on high-Q dipole void mode in a metallic nanoshell.
abstract: We propose a novel type of plasmonic lasing nanostructure consisting of a metallic shell and a gain core. We demonstrate numerically that highly localized void modes of such metallodielectric core-shell nanoparticles have a very high quality factor. We found that the dipole void mode has a lasing threshold as low as 128 cm(-1) at 800 nm as a result of the unique mode distribution within the shell, due to a maximum field enhancement around the void center. The lasing condition for a symmetry-reduced silver nanocup is also investigated and the low plasmonic lasing threshold is sustained provided that the opening angle of the nanocup is smaller than 10°. Our proposal presents a new path toward plasmonic lasers with low gain threshold.
authors.affiliation: Department of Physics and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: J
authors.initials: J
authors.lastname: Pan
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Zhan
authors.forename: C J
authors.initials: CJ
authors.lastname: Tang
authors.forename: Z L
authors.initials: ZL
authors.lastname: Wang