The laser beam is formed by light particles (photons) concentrated and emitted in the form of a continuous beam. To do this, it is necessary to stimulate the atoms of some material to emit photons. This light is channeled with the help of mirrors to form a beam. The technology was created in 1960 by Theodore Maiman. On that occasion, the American physicist stimulated ruby atoms to emit concentrated light. Since then, the laser has evolved and is currently used in household, surgical, industrial, military and space devices – laser beams have even been used to measure the distance between the Earth and the Moon. Although it is possible to create weapons to blind enemies and to intercept missiles (by heating them until they explode), guns that shoot lasers, like the one illustrated below, shouldn’t stop being science fiction anytime soon.
LIGHTS, CAMERA, ACTION
Creating a laser feels like a ballad, with lots of energy, frenetic lighting and mirror play.
Every laser needs an active principle that can be solid, like ruby, or gaseous, like carbon dioxide, inside a closed chamber. The material’s atoms are stimulated to generate light, the main ingredient in a laser beam.
For there to be emission of light, it is necessary to excite the atoms of the active principle. Stimulation can occur by electricity, by light from another, less powerful laser, by a light source, or by chemical reactions. This energizes the electrons and encourages them to try to escape the atoms.
The tendency of the excited atoms is to return to stability, with the electrons returning to their original state. When this happens, the energy that stimulated the electron dissipates in the form of particles of light (photons).
In addition to the external energy that powers the laser cannon, the photons also excite neighboring atoms. With that, the light amplification rolls. The term is mentioned in the acronym that forms the word laser (light amplified by stimulated emission of radiation, in Portuguese).
A pair of exactly parallel mirrors orders the photons that circulate agitated through the cylinder. Instead of bouncing in all directions, the photons start to circulate in the same direction, forming a coherent beam of light, that is, in which the light does not spread out.
The front mirror does not reflect all the light that falls on it. It lets 2% of the coherent beam of light escape from the cannon. That’s the laser beam! The material used to create the beam determines the color of the beam. Laser power is regulated by the amount of energy expended to stimulate light emission.
LASER EVEN AT LEISURE
Applications of technology are in the classroom and on military aircraft
LASER POINTER – The flares used by speakers ended up in football. The rays pointed by the crowd can blind the players
PRINT – The laser marks the content to be printed on a light-sensitive drum. The marked areas attract a colored powder (toner), absorbed by the paper as it passes through the drum.
LASER WAXING –The photons burn the hair down to the root. But to say that this waxing is permanent is nothing more than a myth.
BARCODE READER – The laser focuses on the bright and dark regions and returns the information to the sensor. The data turns into electrical signals and is processed by a computer.
CD AND DVD PLAYER – The laser light focuses on the microscopic reliefs of the discs, on which the data is engraved.
METAL CUTTING AND WELDING – Very high temperature lasers are used in the metallurgical industry. The beam of light is accompanied by compressed air to complete the cut.
TATTOO REMOVAL – Specific beams of light for each pigment color penetrate the skin and only act where it is painted – skin without paint is harmless. The procedure takes several sessions.
EYE SURGERY – Cutting the retina with a light instead of a scalpel decreases the risk of infection. Heat also prevents bleeding by cauterizing the severed vessels.
HOLOGRAPHY –It is a beam of concentrated light that draws those colored 3D images, on a silver background, printed on credit cards and figurines
MISSILE SYSTEM – The US is testing a plane that shoots down rockets. Before reaching the target, the missile is superheated and detonated by a laser that follows it for five seconds.
Read too:
– What was the Star Wars Project?
– How does holography work?
– Is it possible to create laser guns?