Laser Technology


Laser Technology Essay, Research Paper

The laser is a device that a beam of light

that is both scientifically and practically of great use because it is

coherent light. The beam is produced by a process known as stimulated emission,

and the word “laser” is an acronym for the phrase “light amplification

by stimulated emission of radiation.”

Light is just like radio

waves in the way that it can also carry information. The information is

encoded in the beam as variations in the frequency or shape of the light

wave. The good part is that since light waves have much higher frequencies

they can also hold much more information.

Not only is the particle

the smallest light unit but it is a particle as well as a wave. In beams

of light whether they are ordinary natural or artificial the photon waves

will not be traveling together because they are not being emitted at exactly

the same moment but instead at random short bursts. Even if the light is

of a single frequency that statement would also be true. A laser is useful

because it produces light that is not only of essentially a single frequency

but also coherent, with the light waves all moving along in unison.

Lasers consist of several

components. A few of the many things that the so-called active medium might

consist of are, atoms of a gas, molecules in a liquid, and ions in a crystal.

Another component consists of some method of introducing energy into the

active medium, such as a flash lamp for example. Another component is the

pair of mirrors on either side of the active medium which consists of one

that transmits some of the radiation that hits it. If the active component

in the laser is a gas laser than each atom is characterized by a set of

energy states, or energy levels, of which it may consist. An example of

the energy states could be pictured as a unevenly spaced ladder which the

higher rungs mean higher states of energy and the lower rungs mean lower

states of energy. If left disturbed for a long time the atom will reach

its ground state or lowest state of energy. According to quantum mechanics

there is only one light frequency that the atom will work with. There are

three ways that the atom can deal with the presence of light either it

can absorb the light, or spontaneous emission occurs, or stimulated emission

occurs. This means that if the atom is at its lowest state that it may

absorb the light and jump to its high state and emit extra light while

doing so. The second thing it may do is if it is at its highest state it

can fall spontaneously to its lower state thus emitting light. The third

way is that the atom will jump from its upper state to its lower state

thus emitting extra light. Spontaneous emission is not effected by light

yet it is rather on a time scale characteristic of the states involved.

That is called the spontaneous lifetime. In stimulated emission the frequency

of the light is the same as the frequency of the light that stimulated


Carbon-monoxide, color

center, excimer, free-electron, gas-dynamic, helium-cadmium, hydrogen-fluoride,

deuterium-fluoride, iodine, Raman spin-flip, and rare-gas halide lasers

are just a few of the many types of lasers there are out there in the world.

The helium-neon laser is the most common and by far the cheapest costing

about $170. The diode laser is the smallest being packed in a transistor

like package. The dye laser are very good for their broad, continuously

variable wavelength capabilities.

The theory of stimulated

emission was first proved by Albert Einstein in 1916, then population inverse

was discussed by V. A. Fabrikant in 1940. This led to the building of the

first ammonia maser in 1954 by J. P. Gordon, H. J. Zeiger, and Charles

H. Townes. In July of 1960 Theodore H. Maiman announced the generation

of a pulse of coherent red light by means of a red crystal- the first laser.

In 1987 Gordon Gould won a patent he had been trying to get for three years

to build the first gas-discharged laser which he had conceived in 1957.

In that same patent the helium-neon was included.


Bertolotti, M., Masers and lasers: An

Historical Approach (1983);

Kasuya, T., and Tsukakoshi, M., Handbook

of Laser Science and Technology

(1988); Meyers,Robert, ed., Encyclopedia

of Lasers, 3d ed. (1989); Steen, W. M., ed., Lasers in Manufacturing (1989);

Whimmery, J. R., ed., Lasers: Invention to Application (1987); Young, M.,

Optics and Lasers, 3d rev. ed. (1986).

Додати в блог або на сайт

Цей текст може містити помилки.

A Free essays | Essay
6.7кб. | download | скачати

Related works:
Laser Surgery
Dissociation of Benzene Molecule in a Strong Laser Field
It Technology
Technology 2
Technology 3
© Усі права захищені
написати до нас