In Greek mythology, the Titan Prometheus gave the gift of fire to Humanity. It provided warmth, light, and energy. Whether or not you believe that myth, humanity has learned to concentrate that light into beams of unimaginable ability:

Lasers.

What does that word make you think of first? Science fiction ray guns? A secret agent strapped to a table where a metal-melting beam of light inches toward him? Or possibly the master thief throwing dust in the air to reveal a deadly maze of red laser beams guarding the gem?

Those are all trendy but outdated images of the laser. Today, lasers vanquish distinctive foes such as unwanted hair, image correction, and even tumors.

How is a beam of light able to delicately reshape the surface of the eye, yet still be able to cut steel?

LASER is an acronym for "Light Amplification by Stimulated Emission of Radiation." In this description radiation doesn't refer to nuclear radiation, but to electromagnetic radiation. The electromagnetic spectrum includes radio waves, microwaves, infrared light, observable light, ultraviolet radiation, and X-rays. Some light wavelengths are visible, and other are not unless unique gear is used (e.g., infrared cameras, night-vision goggles).

Lasers function by concentrating the strength of a range of forms of light. The strengthened beam is an almost perfectly directly beam, called a coherent beam. "Coherent" mode that almost all of the light energy (photons) are traveling in the same direction. The laser light energy stays focused on a lesser area with larger ability.

Compare this to an incoherent light supply such as a light bulb, which emits photons in countless directions and at loads of wavelengths. This is the job of a bulb, because we wish observable energy dotted out as much as possible.

A flashlight additionally uses a light bulb, but also contains a curved mirror to approximate a more coherent beam. The light from the strongest commercial spotlight (in essence a giant flashlight) will disperse in the atmosphere after a relatively quick distance. A laser beam can be bounced off the moon!

A closer analogy to a laser is a magnifying glass. Remember as a child how you got the sun's rays to focus on a tiny spot that got hot enough to burn? That's similar to what a laser does, unless you moved the magnifying glass. Then the focus was lost and the sunlight was no longer concentrated. Because the laser employs a coherent beam, that essentially means it stays focused no matter the distance! Think of it link an infinite magnifying glass.

The 60s heralded new breakthroughs in laser technology. Theodore Maiman built the first working optical light laser in 1960. It used a real state laser that incorporated a synthetic ruby. The first semiconductor laser was developed in 1962.

Today, the three most universal lasers are gas, solid state and semiconductor.

Helium-neon lasers

Helium-neon lasers are the cheapest visible light lasers. In 1974, they were used as bar code scanners, first in grocery stores and now in many large retail stores. The laser is scanned across a bar code and tells the cash register's computer the price of the item. It can furthermore afford information on sale discounts, stock numbers and inventory.

Lasers are used by surveyors and machinists to measure distance and align parts. They are used to measure the speed of light in a laboratory, distances on a street or action along an earthquake fault.

Argon lasers

Argon lasers are used by the medical profession to make incisions that are more exact than scalpels. There is less scarring with lasers because they can be used in place of sutures to fuse the incision together after surgery. Lasers are used in eye surgery to weld the retina back together. Lasers are also used to correct poor image by reshaping the cornea. One of the newest medical uses for lasers is to make little holes in the heart so that pathways are created for new blood flow. This helps prevent core attacks. The only downside is the increased cost over conventional surgeries.

Argon lasers make holograms, and are used in spectrochemistry, optical image processing, semiconductor processing and laser light shows.

Solid state lasers

Solid state lasers are used for cutting, welding, heat treating and marking of resources. Jewelers can do very exact cuts when using lasers to cut fine gems. Lasers allow better cuts on metals and the welding of dissimilar metals.

Scientists use solid state lasers to observe the slightest movements in matter. Law enforcement has long used laser technology for gauging the speed of cars. The military is using solid state lasers in rangefinders, laser guided bombs and satellite communications systems.

The largest lasers in the world are solid state lasers. Countless of the laser projectors for light shows and for other laser displays employ solid state quite than argon or krypton gas lasers.

Semiconductor lasers

Semiconductors are used to produce lasers with undetectable light. The first successful consumer product to contain a laser, the laserdisc player, was introduced in 1978. In 1983, the compact disc player was introduced. Currently, lasers are also used in DVD players, cellular phones, laser printers and wireless Web transmission.

Lasers can perform a multitude of different tasks at diverse power levels. Particular light wavelengths and beam strengths can be achieved by altering the light supply, authority source, and even the color of the light. This intense versatility allows both the shaping of a delicate cornea and the cutting of industrial steel.

The laser in your CD player won't cut steel, but neither can the industrial laser play a music CD lacking destroying it. Matching the right laser ability to the right job enables us to safely harness this magical new fire.