• Spectroscopy and Spectral Analysis
  • Vol. 42, Issue 1, 38 (2022)

Abstract

In this paper, spherical silver nanoparticles and multi-shaped silver nanoparticle were synthesized using the facile solvothermal method. The spherical silver nanoparticle has a narrow single LSPR peak around 400 nm, and a multi-shaped silver nanoparticles resonance region between 400~700 nm. A random laser was achieved in doped polymer film embedded multi-shaped silver nanoparticleson glass. It is experimentally shown that the spherical silver nanoparticles doped polymer film only has spontaneous emission peak, and dye doped polymer film with morphology of silver nanoparticles has a line width of 0.5 nm coherent random laser emission. The threshold is 1.9 mJ·cm-2. Due to multi-shaped silver nanoparticles exhibiting multiple plasmon resonances, spectrally overlapping with the emission of R6G, improving interactions with nearby molecules to stimulate more emission, which is beneficial to the formation of high gain. Further, by changing the pump position, the random lasing emission can be tuned in the range of 20 nm, wavelength ranging from 590.1 to 610.4 nm. It is likely the composition and distribution of silver nanoparticles at different locations are distinct, which change the interaction of surface plasmonic and the scattering ability of photons, leading to different gain effects and distinct closed optical oscillating paths. In addition, considering that multi-shaped silver nanoparticles have a broad localized surface plasmonic resonance region, we investigated whether multi-shaped silver nanoparticles can be used to achieve red random laser. Under the same preparation method, we embedded it into a polymer film doped with DCJTB. The results show that the coherent read coherent random lasing with a wavelength of 675 nm can be generated effectively, and the threshold value is only 0.98 mJ·cm-2. The results of this work are a great reference value in the research of wideband tunable random laser and random multicolor laser.