Random lasing emission from FTO and glass substrates coated with dye doped SU-8 epoxy based polymer

Abstract

The demand for improving dyeing efficiency and photochemical/photo-physical properties of organic-dyes-based random lasers while focusing on eco-friendly procedures, cost effective production and reduced toxicity has been grown for the past few years. In order to fulfill these requirements, an organic dye dissolved in the solution of SU-8 polymer is proposed as the gain medium in a typical random laser structure. Considering adhesion properties of the SU-8 resin, we observe random lasing action in a glass substrate and also fluorine doped tin oxide (FTO) layer covered by the solution of rhodamine B dye doped SU-8 polymer. Line-width narrowing and drastic increase of the emitted intensity confirm the onset of random lasing emission in the proposed structures. When we use alcohol solution as the dye solvent instead of SU-8 polymer, no random laser emission is observed in these structures. It is also shown that due to larger grains of the FTO substrate compared to the roughness of the glass substrate, RL emission occurs more efficiently in the FTO substrate. Obtained results may stimulate facile fabrication of cost effective, intensive and low threshold RLs based on dye doped SU-8 polymer as the gain medium.