# Resonant random laser emission from graphene quantum dot doped dye solutions

## TL;DR

This paper demonstrates the development of resonant random laser emission using graphene quantum dots doped in dye solutions, showing discrete lasing modes and dependence on GQD concentration and pump position, with potential biosensing applications.

## Contribution

It introduces a novel resonant random laser system based on GQDs with experimental analysis of lasing modes and operational parameters.

## Key findings

- Discrete lasing modes with subnanometer linewidths observed
- Lasing threshold identified at specific pump fluences
- Emission characteristics depend on GQD concentration and pump position

## 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.

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Source: https://tomesphere.com/paper/1907.03003