Coupled Modes Enhance Random Lasing in Plasmonic Thin Etalons

In this work, we experimentally and theoretically proved a flexible fine random laser from a two-face etalon plasmonic structure based on PDMS. Accordingly, PDMS was fabricated using the nanoimprint lithography method and coated by a thin gold layer with a thickness of 35 nm using a PVD device and light-emitting polymer (F8PT) to enhance the scattering and efficiency of the random laser. Using a plasmonic gold grating as a substrate, the simulation results compared the upside and downside of the plasmonic etalon structure. Moreover, an enhancement was observed in light transmission, and it is common to predict high efficiency in random lasing properties. The experimental results showed a comparison between normal plasmonic etalon samples and symmetric and asymmetric etalon-based nanostructures with thicknesses of 200, 400 and 600 \(\mu m\) and reported that random lasing properties had better results for samples with thinner spaces based on coupled mode effects. Correspondingly, this was done by increasing the intensity and decreasing the lasing threshold from 22 𝜇J in normal etalon to 16\(\mu J\) in the thinnest etalon structure.