[Image above] Credit: Quasic; Flickr CC BY-SA 2.0
Scientists at the Moscow Institute of Physics and Technology, Institute of Applied Physics of the Russian Academy of Sciences, and the company IRE-Polus have developed a ceramic-based laser that has just the right wavelength to cut its way into key industries.
The team crafted a laser from rare-earth compound lutetium oxide doped with thulium ions (Tm3+:Lu2O3). According to an MIPT press release, the laser’s energy–radiation conversion efficiency exceeds 50%, while other solid state lasers only achieve ~20% efficiency.
In addition, lasers from polycrystalline ceramics offer some significant benefits over single crystal lasers—they are less expensive and easier to manufacture, although the availability of rare-earth elements is a well-documented concern.
While ceramic-based lasers are not a new concept, the thulium ions make this new material perfect for a surgical laser—the ceramic emits infrared radiation with a wavelength of 1966–2064 nm.
“Radiation from the most common infrared lasers, with a wavelength of ~1 µm, has very little absorption and penetrates deep into biological tissue, which causes coagulation and large areas of ‘dead’ tissue,” Ivan Obronov, lead author of the new work and MIPT researcher, says in the MIPT release. “A surgical scalpel needs to ‘operate’ at a very specific depth, which is why 2-µm lasers are used, as they do not damage underlying tissue.”
Surgical 2-µm lasers are often holmium lasers, which are expensive and not all that portable or precise—bad qualities for a surgical laser. “Ceramic lasers have a significant competitive advantage; they are cheaper to manufacture, simpler and more reliable, and approximately four times more compact than holmium lasers. They will be ideal for surgical use,” Obronov says in the release.
In addition to slicing through biological tissues, the new laser could also be useful for cutting and engraving polymers and composites in industrial settings, the researchers say.
The paper, published in Optics Letters, is “Highly efficient 2 μm CW and Q-switched Tm3+:Lu2O3 ceramics lasers in-band pumped by a Raman-shifted erbium fiber laser at 1670 nm” (DOI: 10.1364/OL.41.002298).