Resonant random laser emission from graphene quantum dots doped dye solution

Abstract

Graphene quantum dots (GQDs) are more promising than other kinds of semiconductor QDs because of their photostability and biocompatibility in different applications such as bioimaging, biosensing and light emitting diodes (LEDs). In addition, advances in random lasers (RLs) have led to an emerging desire for developing remote sensing and detecting strategies, lightning and imaging systems that are far cheaper, more precise and simpler. Although combining GQDs and RLs seems promising for the development of advanced biosensing and bioimaging systems, the RLs fabricated based on GQDs have been rarely studied. Here, we report on the fabrication of dye doped GQDs RLs with resonant feedback that are pumped optically with nanosecond pulses. GQDs, synthesized by the pyrolysis of citric acid, are used as scattering centers in an ethylene glycol solution of rhodamine B dye. It is demonstrated experimentally that discrete lasing modes with subnanometer linewidths appear at pump fluences above the threshold. Furthermore, the dependence of random lasing emission characteristics on the concentration of GQDs and the pump position is investigated experimentally.

Optically Transparent Graphene Flakes as Nanogenerator of Microbubbles for Random Lasing in Weakly Scattering Regime

“…The obtained value of linewidth and RL I th for RL emission is comparable to or even less than that of previous reports. [ 19,20,38,39 ] Such an improvement in RL action is due to robust light amplification in the presence of a high density of scatterers, as can be apprehended from the evolution of gain volume, as shown in the inset of Figure 3e‐i. Furthermore, the QF and energy loss are inversely dependent, and therefore, RL emission is achieved easily at a low value of RL I th due to the high value of QF.…”