Ceramic laser for surgery and industry
Physicists have created a prototype of a cheap and reliable laser scalpel based on ceramics
Scientists from MIPT and their colleagues have created a new compact and powerful ceramic–based laser - this device will be used as a low-traumatic and cheap laser scalpel for surgical operations, as well as for cutting and engraving composite materials. The results of the work are published in the journal Optics Letters (Antipov et al., Highly efficient 2 µm CW and Q-switched Tm 3+:Lu 2 O 3 ceramics lasers in-band pumped by a Raman-shifted erbium fiber laser at 1670 nm).
Today lasers are used everywhere: in household electronic devices, in medicine, metallurgy, metrology, meteorology and many other fields. The laser beam arises due to the effect of forced radiation in the so-called active medium, the role of which can be played by gases, liquids, crystals or glasses, the laser wavelength depends on the parameters of the active medium, the efficiency of energy conversion into radiation.
Ivan Obronov, a researcher at MIPT, and his colleagues from the Institute of Applied Physics of the Russian Academy of Sciences and the IRE-Polyus company used ceramics obtained from compounds of rare earth elements – lutetium oxide with the addition of thulium ions (Tm 3+:Lu 2 O 3) as the active medium of the laser. It was thulium ions that provided the ability of ceramics to generate laser radiation.
"Ceramics is a promising type of medium for lasers, since it is obtained by sintering powders into a polycrystalline mass. In production, it is cheaper and simpler than single crystals, which is extremely important for mass adoption. In addition, the chemical composition of ceramics is easy to change, changing the properties of the laser," explains Obronov.
The laser they created converts energy into radiation with an efficiency of more than 50%, while other versions of solid-state lasers have an average efficiency of about 20%, and generates infrared radiation with a wavelength of about 2 microns (1966 and 2064 nanometers). It is the wavelength that makes this laser indispensable for medical purposes.
"The radiation of the most common infrared lasers, with a wavelength of about 1 micron, has a low absorption and penetrates very deeply into biological tissues, which leads to coagulation (adhesion of small parts, for example, blood clotting) and the appearance of significant areas of "dead" tissue. A surgical scalpel must "work" to a strictly defined depth, so two–micron lasers are used that do not damage the underlying tissues," says Obronov.
According to him, doctors usually use two-micron tube-pumped holmium lasers, but these devices are very expensive, rather cumbersome, and not too reliable.
"Ceramic lasers have significant competitive advantages, they are cheaper to manufacture, simpler and more reliable, and about four times more compact than holmium lasers. It will be a good choice for surgeons," Obronov believes.
Another potential application of ceramic lasers is the composite industry. Widespread single-micron lasers cut metal well, but polymers are practically transparent to them. A two-micron ceramic laser, unlike them, can effectively cut and engrave plastic, for example composite materials.
"Composites are being increasingly used in the production of equipment, for example, airplanes. The wing of the new Russian aircraft MS-21 is almost entirely made of composites. A ceramic laser can become a convenient tool for such production," the scientist concluded.
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22.07.2016