Transformation of random lasing to Fabry-Perot lasing: observation of high temperature lasing from carbon dots

Carbon dots (CDs), a subject of academic research, have attracted intense attention due to their intrinsic merits of high stability, low cost, and low toxicity. However, the absence of highly efficient red-emitting CDs restricts their application in a variety of areas including lasers. In this work, red emissive CDs (R-CDs) with a quantum yield as high as 66.7% were prepared using 1,3-dihydroxynaphthalene as the initial source. It is found that the superior optical properties of R-CDs are attributed to the high oxidation degree and high ratio of hydroxyl functional groups on the surface of CDs. Red emissive random lasing at 612 nm was realized from a microcavity by using the R-CDs/epoxy composite as the gain medium at room temperature. Simultaneously, the transformation of random lasing to Fabry-Perot lasing in the same laser cavity at 250 degrees C was observed. This is on account of the declining optical gain which is insufficient to support random lasing in the microcavity at high temperatures. As a result, CD based Fabry-Perot lasing was achieved at a temperature as high as 250 degrees C for the first time.

Automated summary

This study successfully prepared red emissive carbon dots with high quantum yield, attributed to their high oxidation degree and high ratio of hydroxyl functional groups on the surface. Utilizing these carbon dots, red emissive random lasing output was achieved at room temperature, and the transformation of random lasing to Fabry-Perot lasing was observed at high temperatures.