Scientists make microscopic lasers from spheres

Berkeley scientists have found a way to use microscopic spheres as a laser. The technique should, among other things, make it possible to inject the lasers into the body and serve there as a kind of medicine.

In a news post, the university explains how the lasers are made. These are spheres made of a polymer that are no larger than 5 microns in diameter. This makes them smaller than a red blood cell, according to the scientists. Nanoparticles made up of sodium yttrium fluoride together with thulium were used to make the spheres emit light. The latter is more often used to build lasers.

The scientists discovered that if they provide the spheres with energy by shining infrared light on them, light can be emitted. They also did this when they were removed from the freezer years later, so that the whole is quite stable. The spheres also have no trouble emitting light in liquids, such as in the blood.

The advantage of the technique developed by Berkeley is not only that the lasers are microscopic, but also that they can work for hours on end and require considerably less energy to emit light than other mini lasers. For the time being, however, the scientists have no applications, although they have come up with a number of possibilities. They want to use the spheres as medicines, for example by injecting them into the body to manipulate the behavior of nerve cells. This could help address neurological diseases. Controlling optical chips is also possible.

According to the scientists, the results of the study were unexpected; they were looking for spheres for use in brain imaging. In future studies, they want to see whether the light produced can be predicted more accurately, so that the lasers are easier to control. However, it is not known when practical applications will actually be made. The findings of the current research have been published in Nature Nanotechnology.