Random lasing based on plasmonic enhancement from dye-doped capillary tubes with Ag-TiO2 composite nanostructure

Abstract Plasmonics have allowed revolutionary progress in field of random lasers through improvement of the lasing property via surface plasmon resonance (SPR). However, localized surface plasmon resonance (LSPR) spectra of conventional metal nanostructures are too narrow to sufficiently cover both the absorption and emission spectra of dyes. Therefore, in this paper, we fabricate a typical Ag-TiO2 composite nanostructure by a solution-reduction method and dope it into a random-laser system with a dye solution. With the assistance of this new nanostructure with a broadened plasmon-resonance band, the random-lasing device shows a lower threshold, sharper peak, and higher intensity compared with devices with pure TiO2 nanoparticles (NPs) and mixtures of TiO2 and Ag NPs as scattering media. The results further stimulate consideration of the plasmon effects in random laser systems and help in the design of high-performance, cost-effective random laser devices.