Success in Development of Microscopic Laser Source Made of Liquid Assistant Prof. Yamagishi & Prof. Yamamoto

Soft devices that can be bent and folded are attracting attention in the fields of electricity and light research. Traditionally, plastic has been the main material used for such soft devices, but there is a limit to its softness. In this research, we focused on liquid as a material with ultimate softness and succeeded in developing a laser light source made of 100% liquid.

https://www.tsukuba.ac.jp/journal/technology-materials/20230209140000.html

Devices already exist that utilize liquids as some of the elements that make up the laser. However, since the container that produces the laser is made of a hard solid, it cannot be soft. There have been attempts to make the container that produces the laser from a liquid, but they have not been successful because it is difficult to produce spherical micro droplets that can be used stably in the atmosphere.

　In this study, we solved these problems by optimizing the conditions for forming droplets on a substrate with a superhydrophobic surface using room-temperature ionic liquids. The produced micro droplets can maintain a nearly spherical shape on the substrate and are so stable that evaporation is undetectable even in air. Furthermore, the performance was comparable to the best organic microsphere lasers. The droplets can be deformed by extremely weak forces, such as a light breeze, and the performance of the laser can be adjusted accordingly. Using an inkjet printer, arrays consisting of many droplets can be fabricated. This research provides a fundamental material strategy for the construction of stable liquid laser devices and is expected to lead to the realization of new soft optical devices.