A team of researchers at the Moscow Institute of Physics and Technology (MIPT; Moscow, Russia) and collaborators has developed a compact, powerful ceramic-based laser that will have utility in cutting and engraving composite materials, among other uses.
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Ivan Obronov, a researcher at MIPT, and his colleagues from the Institute of Applied Physics of the Russian Academy of Sciences (RAS; Nizhny Novgorod, Russia) and the company IRE-Polus (Fryazino, Russia) used a ceramic obtained from compounds of rare-earth elements—lutetium oxide with added thulium ions (Tm3+:Lu2O3). It was the thulium ions that enabled the ceramic to generate laser radiation.
"Ceramics are a promising type of medium for lasers because they are produced by sintering powders into a polycrystalline mass. They are cheaper and easier to manufacture than single crystals, which is extremely important for mass adoption. In addition, it is easy to alter the chemical composition of ceramics, which in turn alters the laser properties," Obronov explains.
The laser they have developed converts energy into radiation with an efficiency of more than 50% (other types of solid-state lasers have an average efficiency of approximately 20%), and it generates infrared (IR) radiation with a wavelength of about 2µm (1966 and 2064 nm).
Widely used 1µm lasers are useful for cutting metal, but polymers are practically transparent to them. A 2µm ceramic laser, on the other hand, can effectively cut and engrave plastics, such as composite materials that are increasingly being used to produce technological equipment such as aircraft, Obronov says. For example, the wing of the new Russian MS-21 airplane is almost entirely made of composites, he adds.
An additional utility for the laser could be laser surgery, as radiation from common 1µm lasers has very little absorption and penetrates deep into biological tissue, causing coagulation and large areas of dead tissue. Because a surgical scalpel needs to operate at a very specific depth, 2µm flashlamp-pumped holmium lasers are used since they do not damage underlying tissue, Obronov says—but they are expensive and somewhat bulky. The research team's ceramic laser, however, is less expensive to produce and four times more compact than holmium lasers.
Full details of the work appear in the journal Optics Letters; for more information, please visit http://dx.doi.org/10.1364/OL.41.002298.