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 Fe3O4@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 Fe3O4@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 be-tween Fe3O4@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 Fe3O4@Ag NPs/Ag film coupled structure could be tuned from 415 to 810 nm, and that based on Fe3O4@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.

Automated summary

A tunable wavelength nanolaser based on Fe3O4@M (magnetic-plasmonic) core-shell NPs/metal film coupled structure was proposed in this article. The optical properties of the nanolaser with different core-shell NP sizes and gap distances between Fe3O4@M NPs and metal film were investigated using the finite element method. The wavelength of the nanolaser based on Fe3O4@Ag NPs/Ag film structure could be tuned from 415 to 810 nm, and that based on Fe3O4@Au NPs/Au film structure could be tuned from 536 to 779 nm by controlling the gap distance and NP size.