Happy Birthday LASER!
Today is a birthday of the first laser!
The Photonica Exhibition management team congratulates laser industry experts on their professional holiday! And to the laser we wish good luck, well-being, large capacity, development and prosperity within new technologies!!!
On the very same day fifty years ago – December 16, 1960 – Theodore Maiman demonstrated the first laser.
Invention of induced electromagnetic radiation generators – lasers – is a major achievement of the 21st century's science and technology. The laser operation is based on a phenomenon of strengthening of electromagnetic oscillations by means of stimulated, induced radiation of atoms and molecules which was prognosticated as far back as in the year 1917 by Albert Einstein while studying a balance between nuclear systems energy and their radiation. Thereafter, perhaps, the laser invention story begins.
However at that time nobody paid attention to the basic value of this phenomenon. Nobody knew the ways to produce the induced radiation and to apply it.
In 1940, analyzing a gas discharge spectrum, Soviet scientist Valentin A. Fabrikant specified that, using the phenomenon of the induced radiation, it was possible to achieve the light amplification. In 1951, jointly with scientists Fatima A. Butaeva and Mikhail M. Vudynsky, he held his first tests in this area.
In the year 1952 scientists in three countries— Nikolay G. Basov and Alexander M. Prokhorov in Soviet Union; Charles Townes, J. Gordon, H. Zeiger in the USA and J. Weber in Canada— simultaneously and independently of one another offered a new pronciple of generating and amplifying ultrahigh frequency electromagnetic oscillations based on the induced radiation phenomenon.
That allowed creation of centimeter and high-frequency quantum generators called masers which had very high frequency stability. Using masers as amplifiers allowed increasing sensitivity of radio receivers by hundreds of times.
At first the quantum generators used two-level power systems and spatial sorting of molecules with various power levels in an unhomogeneous electric field. In 1955 Nikolay G. Basov and Mikhail M. Prokhorov suggested using three-level power quantum systems and an external electromagnetic excitation field to unbalace the particles.
In 1958 scientists considered a possibility to apply this method for creation of optical band generators (in the USSR Nikolay G. Basov, Bencion M. Vul, Yuriy M. Popov, Alexander M. Prokhorov; in the USA Charles Townes and Arthur Schawlow).
Based on this research results, in December, 1960 Theodore Maiman (USA) constructed the first properly operating optical quantum generator which used a synthetic ruby as an active substance.
After creation of the ruby optical quantum generator there appeared a new word Laser. This word is made up of the first letters of the English expression: «light amplification by stimulated emission of radiation» (laser).
The ruby laser worked in a pulse mode. Its radiation ranked in the visible range red area. Excitation was produced by a powerful light source.
Next year, in 1961, American scientists Ali Javan, V.Bennet and D.Garriott designed a gas laser which used a mixture of helium and neon as an active substance. Excitation of the active substance was produced by a high-frequency generator's electromagnetic field. This laser was able to radiate continuously.
In 1962 scientists of Soviet Union and the United States of America generated the induced radiation in a semiconductor diode that anticipated creation of a semiconductor laser. Soviet scientists Nikolay G. Basov, Bencion M. Vul and Yuriy M. Popov were the first ones to specify a possibility to use semiconductors as active substances in lasers as far back as in the year 1959. American scientist Robert Hall as well contributed to the semiconductor laser creation. The semiconductor laser is activated directly by a current flow. It works both in pulse, and in continuous modes.
Nowadays lasers use a most diverse materials as working substances. Generation is obtained from more than one hundred substances: crystals, activated glass, plastics, gases, liquids, semiconductors, plasma. Organic compounds activated by ions of rare-earth elements can be used as working substances as well.
Scientists managed to get generation using regular water steam and even air. A new class of the gas lasers is invented, so-called ion lasers.
Today it is hard to find a product which would not undergo the laser impact at some stage of its production.
At DVD playback the semiconductor laser as small as one millimeter scans the disk surface. Complicated process of cutting and welding of steel, for example, to make doors of a car, is as well performed by lasers. Internet is basically operated by means of transmitting laser light through fibre optic cables. Each cash-register machine in supermarkets uses a laser beam for scanning bar codes. Nowadays Afghanistan military forces use powerful lasers installed on Hummers. These laser are able to explode any mine onward the road.