A communication authored by Bilkent University and UNAM researchers appeared as the inside front cover article of the March 11 issue of the weekly journal Advanced Materials. The article reports the demonstration of an ultralow-threshold microfluidic single-mode laser using solution-processed colloidal quantum wells (CQWs). The research team was led by Prof. Hilmi Volkan Demir of UNAM and the Departments of Electrical and Electronics Engineering and Physics, and Asst. Prof. Yegan Erdem of UNAM and the Department of Mechanical Engineering.
Microfluidic coherent/planar light sources are very promising for applications in optical detection and sensing in lab-on-a-chip systems. To date, microfluidic lasers have been demonstrated with organic dyes. These systems utilize high flow rates to prevent photobleaching, and therefore require complex operation conditions along with excess material consumption.
The Bilkent team successfully demonstrated the first microfluidic single-mode laser having CQW solution as the gain medium with a record low lasing threshold as compared to all other solution-based lasing demonstrations. This threshold is three orders of magnitude better than previous multimode in-solution lasers obtained with colloidal nanocrystals, owing to the excellent properties of CQWs.
Ultralow threshold allows the observation of lasing in solution without the flow of the gain media, offering the advantage of stable and easy operation. The team’s CQW laser thus provides a compact and inexpensive coherent light source for microfluidics and integrated optics covering the visible spectral region.
The authors noted that their work represents a significant step toward the realization of microfluidic lasers for on-chip sensing as well as imaging applications and further stated that their system holds promise for the development of an easy-to-operate, low-threshold white laser in solution by integrating multiple channels.
Further details can be found at https://onlinelibrary.wiley.com/doi/full/10.1002/adma.202007131