A humidity-tailored film random laser

A humidity-tailored film random laser is proposed and fabricated as a dye organic thin layer with Ag nanoflowers as plasmonic scatterers. By modifying the film's optical thickness with the surrounding humidity, the random lasing's wavelength and peak intensity are well regulated based on the waveguide feedback model. The peak wavelength is blue shifted from 575.18 nm to 568.43 nm and the peak intensity reduces from 3.97 × 104 to 4.0 × 103 a.u. when the air humidity changes from 18.0% to 71.4%, demonstrating the linear behaviors and better humidity sensitivity relative to that of the fluorescence, respectively. In addition, the fabricated random laser has a good time stability. These results may supply a new flexible way to design environment interaction random lasers and tailor their output performances, also promote their practical applications in the fields of smart sensing, internet of things, and environment monitoring.