Last year (2010) was the 50th birth anniversary of laser, a ground-breaking invention that revolutionized technological progress. Laser-(l)ight (a)mplification by (s)timulated (e)mission of (Radiation)-is a device that produces an extremely powerful beam of light waves that are of the same wavelength and are in phase. On this occasion the Siberian Branch of the Russian Academy of Sciences met in a plenary session. As Acad. Alexander Aseyev heading the RAS Siberian Branch said in his opening speech, this "discovery has impacted the course of human civilization and changed the technical countenance of our society". He recalled that the first pulsed ruby laser was launched in the United States on the 16th of May 1960. In this country lasers appeared in 1961 first at the Vavilov Optical Institute in Leningrad (now St. Petersburg), and then at the Moscow Lebedev Institute of Physics. The Siberian Branch of the Science Academy acquired lasers in 1962 in what is now the Novosibirsk-based Institute of Laser Physics.
A new discipline, laser physics, thus came into being.* A great contribution to its advancement was made by Acad. Veniamin Chebotayev, RAS Corresponding Member Sergei Rautian, and by Drs Georgi Krivoshchekov and Yuri Troitsky. Oldtime laser traditions are much alive in Siberia. This was the subject of a press conference held at the Exhibition Hall of the RAS Siberian Branch on the eve of the laser jubilee. Taking part were leading scientists, such as Acad. Sergei Bagayev (head of the Laser Physics Institute), RAS Corresponding Member Anatoly Shalagin (head of the Institute of Automation and Electrometry), Dr. Anatoly Orishich (deputy research head of the Institute
* See: N. Dobretsov, "First Regional Branch", Science in Russia, No. 4, 2007.--Ed.
of Theoretical and Applied Mechanics), among others. Some of the highlights from Maria Goryntseva of the Science in Siberia newspaper.
One of the pioneers in the laser line was the Institute of Radiophysics and Electronics, Acad. Bagayev recalled. In 1950 an exiled physicist, Yuri Rumer, got a job there on the solicitation of Sergei Vavilov, President of the national Academy of Sciences. Before World War II he had been working at Gottingen, Germany, together with Niels Bohr and Albert Einstein. Victimized during the political purges of the late 1930s, Rumer was confined for sometime to a "savvy joint", a special prison for incarcerated creative scientists and experts, where he met two greats, Andrei Tupolev and Sergei Korolev...* In 1962 the first gas laser was built out there, at the Radiophysics and Electronics Institute. Working on it was a team of young scientists headed by Veniamin Chebotayev (elected to the Russian Academy of Sciences in 1992). Years later this talented experimentalist became the first director of the Institute of Laser Physics set up by the RAS Siberian Branch in 1991.**
Long before that, at the initial stage of optical quantum generators (in 1967 and 1968) Chebotayev teamed up with Dr. Vladlen Letokhov of the Moscow Institute of Spectroscopy. They proposed a number of methods (saturated absorption, biphoton absorption in a standing wave field, separated optical fields), that made it possible to up optical resolution by a factor of 106 to 10 . Thus the two scientists laid a groundwork for a new line of research-high-resolution nonlinear laser spectroscopy. This spurred the advancement of atomic,
* See: N. Koroleva, "His Name and Cosmos Are Inseparable", Science in Russia, No. I, 2007.--Ed.
** See: A. Skrinsky, "Cognition of Matter", Science in Russia, No. 6, 2007.--Ed.
molecular and optical physics, and gave birth to innovative original technologies. For this spectacular achievement both merited a top national award, the Lenin Prize, in 1978.
In 1981, Acad. Bagayev said, his research institute solved the problem of converting radiation frequency from optical to radio bands and created the world's first laser timepiece in which a basic time unit, the second, was determined by the number of ultrastable optical oscillations. By that time 10-14 stability sources were obtained, a singular result that made it possible to register the second to an accuracy 105 to 106 higher than if using atomic rubidium or hydrogen microwave clocks. Works on ultrastable lasers opened up essentially novel opportunities for experiments in physics, metrology and other disciplines.
Early in the 2000s the Laser Physics Institute developed the very first femtosecond (10-15s) optical clock. That was really a revolutionary breakthrough in high-precision optical measurements that demonstrated the possibility of improving absolute frequency measurements to 10-16 to 10-18, all the way from the radio to ultraviolet frequency bands. This is important for specifying certain fundamental physical constants, say, in calculating spacecraft flight trajectories, especially on long-distance missions.
Frequency and time standards developed by Siberian scientists, Acad. Bagayev stressed, allow to significantly expand the speed of response of customized navigation devices. The Russian GLONASS (Global Navigation Satellite System)* can thus improve the accuracy of coordinate plotting from a few meters down to the centimeter level. With further progress of the positioning system combining ground measurements and data from the American GPS (Global Positioning System) it will become possible to bring this index down to 20-30 cm.
As to medical applications (and this is also our priority area), our products are not at all inferior to the world's best standards. In fact, some are even superior, like the Melas-S stomatological appliance that removes caries-stricken dental tissues, sterilizes dental cavities before filling and performs other operations-like tartar removal, for instance. Surgeons of the Novosibirsk TB clinic have been using our IR solid-state lasers for as long as fifteen years now, quite good for as many as 300 surgical operations on the lungs and other respiratory organs. Also, the Novosibirsk Research Institute of Traumatology and Orthopedics is using this technology first adopted ten years ago in removing cerebrospinal tumors (in as many as 200 cases of surgery).
* See: Yu. Nosenko et al., "GLONASS: Today and Tomorrow", Science in Russia, No. 5, 2008.--Ed.
Our surgical apparatus Melas-X, Acad. Bagayev went on to say, is superior to conventional electric knives in its cutting and haemostatic characteristics. It brings down blood losses twofold, that's its chief advantage, and thus is indispensable in gynecological, urological, neurosurgical and other operations.
Another apparatus, Melas-cardio, is used in cardiovascular prosthetics. It measures graft tissues to an accuracy of 10 µm, puts the topology of a graft on the display, maps the desired elements in keeping with the assigned parameters and excises them. This is a fast and high-precision apparatus, which is all-important in cardiology, boosting the efficiency of a surgeon's work more than fivefold. The Melas-cardio is at work in the Kemerovo cardiological center.
It was in Novosibirsk that the first excimer(gas) 193 nm laser was created in the 1990s. Today it is the essential part of the world's ophthalmological devices.* It
* See: I. Shcherbakov, "Laser Physics in Medicine", Science in Russia, No. 5, 2010.--Ed.
corrects myopia, longsightedness and astigmatism by changing the curvature of the external surface of the cornea. Up to 1.5 mln people need such eye surgery each year worldwide, Acad. Bagayev said in conclusion.
The next speaker at the press conference was Anatoly Shalagin, a RAS Corresponding Member heading the Institute of Automation and Electrometry engaged in this area of research since 2002. In these eight and some years it has scored a very good record of achievement on a world scale. Its fiber optics laboratory under Dr. Sergei Babin is the world's pioneer in obtaining the largest bands of laser generation wavelengths (over 50 nm in different spectral regions). Among other things, this laboratory has achieved an effective frequency doublings at setups generating in blue-green and yellow-red regions with possible spin-offs in biomedicine; also, it has developed single-frequency devices for metrology as well sensor systems for power engineering.
The research center is working in tight cooperation with the world's leading institutions. Joining hands with colleagues of Aston University of Great Britain, it has built the world's longest optical-fiber laser. The newly discovered "limit" of increasing a linear resonator's length up to 300 km and more means a classical type of radiation realized within this range, producing further on a different mode of generation. This is a good incentive for new Russian-British research projects.
Right now the Automation and Electrometry Institute, in collaboration with other research centers of the RAS Siberian Branch, is working on a DNA sequencer, a unique apparatus capable of decoding genetic information with the aid of a laser. Scientists suppose that soon it will become possible to learn what diseases in particular man is predisposed to, and what should be done to prevent them. Analogs of a similar apparatus are now on hand, and the production of such devices is onstream in the United States. Still and all, the DNA sequencer is not yet within everyone's reach. The Russian-made sequencer would be installed in each clinic and this, according to Dr. Shalagin, would be the first step toward accessible genomic medicine.
Next to speak was the director of the Institute of Theoretical and Applied Mechanics Anatoly Orishich who focused attention on powerful lasers used in the technological machining of materials. He called attention to the contribution of Siberian scientists in this area. The overall world trend, he said, shows: if the "knife" (cutting tool, mill or any other tool) was the chief element of machining in the 20th century, now, in the 21st century, this role is to be taken on by the laser beam. Instead of conventional techniques, laser beams are being used in a variety of operations, such as cutting out, welding and heat treatment as well as in reinforcing, engraving and novel technologies imparting extraspecial hardness to materials (laser-powder surfacing, composites, mechanical working). This technology is in use in the automobile, machine-building, elec-trotechnical, instrument-making and other industries.
The Theoretical and Applied Mechanics Institute has amassed great practical experience in developing 1-10 kW industrial lasers. Since 1972 it has been making CO2 lasers with the convective cooling of working fluids. Such setups, known for high reliability and economy, show good performance in industrial manufacturing. They cost half as much as foreign analogs.
Their self-filtering resonator is a real wonder: it produces quality high-power beams as strong as 10 kW. Our lasers alone, Dr. Orishich stressed, can work on technical purity gases and CO2-air mixtures (without N2 and He). Before 1980 many of the scientific bodies of Moscow, Leningrad, Nikolayev, Kazan and other cities had been involved with like technologies. Yet it was our article that was picked for full-scale production.
As said above, laser is also used in welding, apart from cutting. This is a new word in science. Welded joints obtained by conventional techniques are not as strong as the basic metal. Such joints will do for ships and cars, not aircraft, though. This is why riveting is still being used in the aircraft industry. Today we are looking for new ways of laser welding in civil and military planes. We have found a technology making it possible to obtain welded parts as strong as the basic materials. We owe this to nanopowders acting upon metal crystallization processes in a joint and imparting a good structure to it.
Our products have won world recognition. Our 8 kW laser setup was quite a sensation at a World Fair of novel technologies held in Hannover, Germany, in 2005. This is an eloquent fact showing that Russian scientists are still in the lead in many of the fields of laser physics and engineering.
M. Goryntseva, Laser Jubilee, Science in Siberia, No. 49, 2010
Photo, D. Golubeva (Info Portal of the Academy of News, Novosibirsk)
Prepared by Marina KHALIZEVA
Опубликовано на Порталусе 18 сентября 2021 года
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