Resonant random laser emission from graphene quantum dots doped dye solution

In this letter, we report on the fabrication of dye doped graphene quantum dots (GQDs) random lasers with resonant feedback that are optically pumped with nanosecond pulses. GQDs, synthesized by the pyrolysis of citric acid, are used as the scattering elements in an ethylene glycol solution of rhodamine B dye. It is experimentally demonstrated that using GQDs instead of titania nanoparticles not only results in the multimode random lasing emission, but also increases the operating lifetime, significantly. We observe discrete lasing modes with subnanometer linewidths at the pump fluences above the threshold. Furthermore, the dependences of the random lasing emission characteristics on the pumping position and concentration of GQDs are investigated, experimentally.