Full-visible range wavelength-tunable SPASER based on Fe3O4@M (M = Ag or Au) magnetic-plasmonic core-shell nanoparticle/metal film coupled nanostructure.

The movement of magnetic nanoparticles (NPs) can be controlled by an external magnetic field. And Fe 3 O 4 @M (M = Ag or Au) core-shell NPs can exhibit both magnetic and plasmonic properties simultaneously. In this article, we theoretically proposed a plasmonic coupled nanolaser with tunable wavelength in full visible light range based on Fe 3 O 4 @M (magnetic-plasmonic) core-shell NPs/metal film coupled structure. We investigated the optical properties of the plasmonic coupled nanolasers with different core-shell NP sizes and gap distances between Fe 3 O 4 @M NPs and metal film by the finite element method (FEM). By controlling the gap distance and NP size, the wavelength of the plasmonic nanolaser based on Fe 3 O 4 @Ag NPs/Ag film coupled structure could be tuned from 415 to 810 nm, and that based on Fe 3 O 4 @Au NPs/Au film could be tuned from 536 to 779 nm. This work provides us a theoretical basis to real-time tune the wavelength of the plasmonic coupled nanolaser based on a liquid gain environment under an external magnetic field. • Magnetic-plasmonic nanolaser based on a coupling between LSP and SPP was designed. • Fe 3 O 4 @M (M = Ag or Au) core-shell NPs/metal film coupled structure was developed. • Optical properties with different NP sizes and gap distances were studied. • SPASER wavelength can be tuned in a range of 40–98 nm by changing gap distance. • Wavelength tunable range was extended to full visible region by changing NP size. [ABSTRACT FROM AUTHOR]