Statistical Identification of Coherent and Incoherent Random Lasing from Carbon Dots

Here we demonstrate RL emission at ~565 nm from green emitting CDs (gCDs), and we use the emitted light as a light source for speckle-free microscopy of biological tissues and microparticles. The emission of the CD-based RL is thoroughly studied as a function of experimental conditions, and well-established mathematical tools in the field are used to perform a detailed statistical study of the lasing output. The CD-based RL displays ultra-narrow (~ 0.70 nm) emission lines over a comparatively broader (~10 nm) background. These two emissions are due to, so-called, coherent and incoherent RL. Their relative weight can be controlled by an appropriate choice of experimental conditions, allowing to tune the characteristics of RL light. The results demonstrate the potential of gCDs as a viable alternative to environmental unfriendly, scarce, or chemically unstable nanomaterials as gain media for RL with customizable emissions.