Optics and Photonics Society of Iran

In this paper, we use graphene oxide as the scattering medium in random lasers. Light amplification is provided by RhB dye solution via stimulated emission process. By investigating the dependence of the emission spectrum on the pump energy density, we observe that some narrow peaks with linewidth of approximately 1 nm appear in the emission spectrum when pump energy density exceeds a threshold value. The number of these peaks increases by increasing the pump energy density and a strong competition between the lasing modes is observed. Furthermore, we measure the threshold pump energy density for the fabricated sample based on the solution of RhB dye and graphene oxide. Then, we compare the emission spectrum corresponding to the solution of RhB dye and graphene oxide with the emission spectrum corresponding to the solution of dye alone. Since only the broad spontaneous emission spectrum is observed in the emission spectrum of neat dye solution, the resonant feedback of the random laser is then provided by light multi-scattering from graphene oxide.