13:45 〜 14:15
▲ [13p-2C-1] [JSAP-OSA Joint Symposia 2015 Invited Talk] Plasmonically Controlled Lasing in Metallic-Dielectric Core-Shell Nanoparticles
キーワード：Plasmon laser,Core-shell nanoparticles
Conventional lasers built on dielectric cavities cannot have dimensions smaller than half the optical wavelength due to the diffraction limit of light. This long-standing barrier can be overcome with plasmonic nanocavities that rely on surface plasmons (SPs), which are collective electron oscillations at a metal-dielectric interface. These SP modes can provide feedback on the nanometer scale and open the path to lasing as long as an optical gain medium placed near the metal nanostructure compensates for dissipative losses. This new compact coherent source has been named “SPASER” or plasmon laser. Since plasmon modes have no cutoff, SPASER can offer coherent optical fields at truly nanometer scales.
State-of-the-art SPASERs have been achieved through several approaches involving the amplification of both propagating surface plasmon polaritons (SPPs) generated in planar structures and localized surface plasmons (LSPs) in a nanoparticle geometry. For most SPP-based SPASERs, the optical cavity is specifically designed (e.g., a Fabry-Perot type cavity) to provide intense optical feedback in one or two dimensions. In contrast, the optical feedback in LSP-based SPASERs arises from the intrinsic plasmon resonance, which provides three-dimensional confinement. A single-particle plasmon nanocavity is of particular interest because it can support an ultra-high Purcell factor F as a result of ultra-small mode volume V. Nevertheless, so far there is only one report on an LSP-based SPASER which consisted of dye-decorated gold-silica core-shell nanoparticles as resonant cavities.
In this paper, wavelength-tunable SPASERs are demonstrated for a plasmonic structure composed of a monolayer of mesoporous silica-coated Au nanorods (Au@MSiO2NRs) as plasmonic nanocavities and organic laser dyes as optical gain media. By choosing a particular organic dye and adjusting the doping level, the resonant wavelength of SPASER is tuned from 562 to 627 nm with a spectral linewidth narrowed down to 5 ~ 11 nm. This work provides a versatile route towards SPASERs at extended wavelength regimes. The results of numerical simulations concerning anisotropic SPASERs in dielectric core–metal semishell nanoparticles will be presented.
State-of-the-art SPASERs have been achieved through several approaches involving the amplification of both propagating surface plasmon polaritons (SPPs) generated in planar structures and localized surface plasmons (LSPs) in a nanoparticle geometry. For most SPP-based SPASERs, the optical cavity is specifically designed (e.g., a Fabry-Perot type cavity) to provide intense optical feedback in one or two dimensions. In contrast, the optical feedback in LSP-based SPASERs arises from the intrinsic plasmon resonance, which provides three-dimensional confinement. A single-particle plasmon nanocavity is of particular interest because it can support an ultra-high Purcell factor F as a result of ultra-small mode volume V. Nevertheless, so far there is only one report on an LSP-based SPASER which consisted of dye-decorated gold-silica core-shell nanoparticles as resonant cavities.
In this paper, wavelength-tunable SPASERs are demonstrated for a plasmonic structure composed of a monolayer of mesoporous silica-coated Au nanorods (Au@MSiO2NRs) as plasmonic nanocavities and organic laser dyes as optical gain media. By choosing a particular organic dye and adjusting the doping level, the resonant wavelength of SPASER is tuned from 562 to 627 nm with a spectral linewidth narrowed down to 5 ~ 11 nm. This work provides a versatile route towards SPASERs at extended wavelength regimes. The results of numerical simulations concerning anisotropic SPASERs in dielectric core–metal semishell nanoparticles will be presented.