LaserS

The person never wanted to live in darkness; it has struck out many various light sources - from sunk in the past stearin candles, gas lamps and kerosene lamps up to lamps of an incandescence and fluorescent lamps which today illuminate our streets and houses. One more light source the laser also has appeared.

This light source is completely unusual. As against all other sources, it at all is not intended for illumination. Certainly, at desire lasers may be applied in quality extravagance lightings. However to use a laser ray with a view of illumination it is so irrational how to heat a room burnt in a fireplace bank notes. As against other light sources, the laser generates the light rays, capable to engrave, weld, cut materials to transmit the information, to realize measurements, to inspect processes, to receive especially pure substances, to direct chemical responses.

Light ray! For a long time the person in the dreams saw in it the reliable and mighty assistant freely penetrating into dungeons, capable to destroy any barrier and to protect from any enemy. To an allmighty light ray many writers - visionaries have converted. Novels " War of the worlds " Herberd Wells and " the Hyperboloid of engineer Garina " by A.Tolstoy are world famous. Surtainly, in these novels the thermal and light ray appeared in hands of forces of evil which used rays for destruction, for acquisition of authority above mankind. People dreamed of the ray – work, the ray - assistant, a ray - creator. This dream could come true in our surprising time. A reality of steel not the monstrous martian generator of thermal rays or a hyperboloid of world supremacy of the person - hater possessed by idea, and the laser which today it is successful “work” in clinics, on factories, building sites, in research and development laboratories.

The invention of the laser ranks with the most produced achievements of science and technology of XX century. The first laser has appeared in 1960, and at once began rough development laser engineering. In short time various types of lasers and the laser devices intended for the decision of concrete scientific and engineering problems were created. To laser engineering of all a quarter of century, however lasers had already time to win strong positions in many branches of a national economy. So it really surprising rays! It really a surprising beam..

2. First who began studying the laser, the greatest scientific Albert Einstein who has shown that there are two various processes of an emission of energy by molecules of substance was. Alongside with the "usual" process of an emission known as a spontaneous emission, it should be observed, how the Einstein, the process of an emission occurbing not spontaneously, and under action of radiation of an environmental molecule of medium figured. The einstein has termed this process by induced (stimulated) radiation.

Have passed decades before scientists were convinced, that the stimulated radiation "thought up" by the Einstein not only really exists, but, moreover, under certain conditions may play the important role. This process also underlies operation of the laser. The word "laser" is made of initial letters of English word collocation Light Amplification by Stimulated Emission of Radiation, that in translation on Russian means " amplification of light stimulated radiation ".

The key diagram of the laser is prime. It includes the fissile device (the fissile medium), the device for ways of pumping the fissile device and a mirror of the optical resonator. Despite of simplicity of a key diagram, lasers differ a major variety. There are very many various types of lasers. They differ from each other appearance, the sizes, a construction. Alongside with lasers - the babies who are freely finding room on a palm, are available lasers - giants which length reaches several tens meters, and the mass is measured by tons. Getting acquainted on a lesson in a study of physics with the helium - neon laser, the schoolboy fearlessly substitutes a hand under a laser beam. Having come in the modern shop of metal working, it may see as the powerful СО2-laser easily and promptly slits steel leafs. A variety of lasers speaks application in them of different types of the fissile mediums and different expedients ways of pumping. As the fissile mediums the dielectric crystals, special glasses, semiconductors, fluid solutions of dyes, gas intermixtures are used.

Gas lasers.

 They were created in 1960. Their working substance - the various gases made in glass tubes. The tube with excited gas shines, as an advertising inscription in a show-window of shop, and from its end faces there are beams of different color, by what gas in it is made. The intermixture of helium with a neon gives a red beam, an argon - dark blue, a xenon - green, a krypton - yellow, and carbonic gas - an invisible thermal, infrared beam.

There is even a laser on water pairs. Such " the steam machine " at the end of XX century gives powerful thermal radiation. Length of its wave hardly more one tenth millimetre. This most long-wave radiation received by means of the laser.  

The liquid laser. Have designed it, certainly, not to force to work in lasers of substance in all their three states - solid, liquid and aeriform, - that, as they say, to anybody it was insulting not. Fluids unite in themselves advantages and solid and aeriform laser materials: the density of them of all in two - three times is lower than density of solid bodies (instead of in hundred thousand times, as density of gases). Therefore quantity (amount) of their atoms in unity of volume approximately equally. Means, the liquid laser is easy for making same powerful, as the laser solid-state. Besides the fluid too can be pumped over through working volume, continuously maintaining its low temperature and high activity of its atoms.  

Lasers on dyes. They are termed so because their hydraulic medium - a solution of aniline paints (like with what mistresses of a house paint a wool and a cotton in water, spirit, an acid and other solvents. Solutions may radiate impulses of light of a various wave length - from ultraviolet up to infrared light - and power from hundreds kilowatts up to several megawatts, depending on what dye stuck in a flat tray. Lasers on dyes help to track a state of an atmosphere. The modern cities are covered with "cap" of dusty, smoked air. It is possible to judge a degree of its pollution on as far as it is strong in it laser beams with a different wave length are diffused. In clean air light is not diffused, its beams become invisible. Now we are witnesses all of extending practical application of lasers. They may be used almost in all spheres of human activity. Due to the unique properties lasers become the instrument of knowledge of world around. Perspectives of use of laser engineering in interests of mankind are really grandiose. It has allowed to apply lasers in medicine.

Laser in medicine.

Practical use of lasers in surgery began in the USSR in 1966 in Institute of surgery of a name of A.V.Vishnevskogo (under the direction of academician A.A.Vishnevskogo.) The laser scalpel was applied in operations on interior bodies of chest and belly vacuities. Now by a laser beam make skin-plastic operations, the gullet, a stomach, intestines, kidneys, a liver, a spleen and other interior bodies operate. Are taken the first steps on operating heart. Is very tempting to use a laser scalpel in operations on bodies where many blood vessels are especial, for example, on a liver, a spleen, heart. In this connection it is important to underline, that thanking of lightning of action the beam of the laser (pulsing) does not cause a pain and other unpleasant sensations. This property of laser radiation has huge value for surgery as at laser operations it is not required anesthesia which any surgical intervention but which application for some patients is unsafe now not bypasses.

The laser is capable not only to facilitate life of healthy people, it may and treat patients.

There is a surgical operation. In the intense silence operating abrupt commands of the surgeon are audible only: " the Scalpel! ", " the Hold-down! ", " the Tampon! ".

By scalpel make a slit. A hold-down overlap large blood vessels with which it was necessary to cut. A tampon delete blood from an operating field. It is a lot of blood; except for major vessels, there is still a set fine, cappilary which any more you will not press. Now are able to stop blood various to expedients, and as early as years hundred fifty back were necessary to cauterize a wound "to make" the ends of vessels and to not give them to effuse with blood. Surgeons for a long time dreamed of the tool making a bloodless slit. It is good also that it was It is good also that it "was more gentle". You see today surgeons know how to make operations on a retina of an eye and interfere in sacred sacred an organism - a human brain. To boss there a scalpel - all the same what to repair hours an axe.

The modern engineering has offered the instrument combining both these requirements, - a light ray!  

What may be more gentle than a tangency of a ray of light? It is possible to make a laser ray a section in width in a thousand share of a millimeter. On energy which it bears(carries), and time of its effect, it may "make" a vessel or, on the contrary, to punch in it a hole.

It is especially convenient there was a laser in ophthalmology - areas of the medicine knowing sight. The laser ray can be entered into an eye directly through a pupil. With its help it is possible to saw a unnecessary vessel to make what flows past and to liquidate traces of haemorrhages. Today after long-term practice of treatment with their help hardly it is possible to tell, that laser surgery of an eye - on a correct path.

By means of the laser make operations of a stomach and an intestines. Their walls consist of many stratums of a fabric penetrated with blood vessels. At operation these stratums sew serially, strongly injuring thus a fabric. Besides all time remains probable, that any stratum will be casually punctured, it inevitable will reduce in a peritonitis - to an inflammation of a belly cavity. The laser ray may is accurate, a stratum behind a stratum "to weld" fabrics and to stop a bleeding.

Any surgical instrument before operation carefully sterilize. The laser ray not only does not require it, but also itself may disinfect wounds, killing microbes and evaporating dying off fabrics.

The salutary ray can be entered directly into a stomach of the patient by means of a flexible optical path and to operate, not opening a belly cavity. And not only in a stomach it is possible to enter an optical path, but also into heart. The laser ray is capable to carry out operation on heart from within, for ever having saved the patient from sufferings.

Teeth, probably, treated all. And if is not present, almost for certain to everyone in his life this doubtful pleasure is necessary to feel. Set of people look at a dental study, as on the chamber of tortures where the principal instrument of tortures is, certainly, a drill. But it is necessary: from the patient it is necessary to delete turned black, staggered caries a fabric before to superimpose a seal.

However it is similar, that "scoffer" horrors shortly will depart in area of legends: instead of a drill already try to apply the laser, and not without success. The light pulse is well reflected from a white brilliant surface of a healthy dental fabric and absorbed darkened, ill which he warms up and evaporates together with microbes.

New opportunities of laser biostimulation will be detected. With the help of laser radiation it will be possible to make active power processes in nervous system, even more to develop protective and regenerative abilities of a human body. The modern person swallows many tablets - " from nerves ", from cold at disorders of those or other organs. He swallows them when to him it is hurt or terrible when to him it is not slept when he is excited or depressed. So may be, the salutary laser ray will help him to be liberated, at last, from this harmful habit?

  The conclusion.

Lasers appeared much more interesting devices, than staggered imagination of writers - visionaries "гиперболоид" or "генератор a thermal ray ", intending, as a matter of fact only for destruction. The reality appeared much more brightly and the richman of imagination. Today lasers successfully трудятся on modern manufacture, consulting(coping) with the diversified problems(tasks). A laser ray раскраивают fabrics also cut steel sheets, weld кузовы automobiles and weld the smallest details in the radio-electronic equipment, punch in fragile and superhard materials. In hands of the surgeon the laser ray has turned to a scalpel having a series of surprising properties. Lasers are widely used in modern кон6трольно-measuring devices, computer complexes, systems of a location and link. Lasers allow quickly, safely to inspect impurity of an atmosphere and a surface of the sea to determine the most loaded sites of details of different mechanisms, defines(determines) internal defects in them. The laser ray becomes the reliable assistant to builders, cartographers, archeologists, criminalists. The area of application of lasers in scientific researches - physical, chemical, biological continuously extends.  

Especially it is necessary to mark, that mastering of laser methods or, in other words, laser techniques considerably raises efficiency of modern manufacture. Laser techniques allow to realize the most full automation of productions. Simultaneously thus the raw material and working hours is saved, quality of production raises. For example, practically instant punched hole of holes laser radiation many times over augments productivity of operation of the driller and besides essentially raises quality of this operation. Laser manufacture of microcircuits differs high efficiency and excellence. In both examples industrial operations easily give in to automation; control by a laser ray may undertake a special computer. Confidently it is possible to assert(approve), that introduction and perfecting of laser techniques will reduce in qualitative change of all shape of modern manufacture.

Are huge and впечатляющи reachings of laser technique of today. Tomorrow's day promises even more grandiose свершения. With lasers link many hopes: from creation of volumetric cinema up to the decision of such global problems, as installation of long-distance ground and underwater optical link, a solution of secrets of photosynthesis, a realization of a controlled thermonuclear response.

The given abstract is an attempt popularly to tell about a role of lasers in the modern world. We have told both about already reached successes of laser engineering, and about perspectives, about those hopes which connect to its development. As a reality and hopes are interlaced here wonderfully.

At the beginning of a development of laser engineering French физик Луи де Бройль has told: _Лазеру уготовано the big future. It is difficult to foresee, where and as it(he) will be applied, but I think, that the laser is whole engineering epoch._  

Since then has passed more than twenty years. Time has shown, that the scientist was right. Will pass ten more - fifteen years, and many of you will adjoin to laser engineering and will discover new properties at it becoming habitual, of a gear, and someone, maybe, will make unprecedented opening which we today and may not imagine with its help! You see forty - fifty back might not present years, that from the amusing mathematical funny thing which is not having, appear, any physical sense, such remarkable invention, as the laser will be born.