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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.
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?
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.