| New applications of laser technology are being | | | | Argon lasers are used by the medical profession to |
| developed constantly. Laser technology was long the | | | | make incisions that are more precise than scalpels. |
| stuff of science fiction, but today it is used in CD | | | | There is less scarring with lasers because they can be |
| players, dental drills, laser saws, high-speed metal | | | | used in place of sutures to fuse the incision together |
| cutting machines, measuring systems and a host of | | | | after surgery. Lasers are used in eye surgery to weld |
| other products. | | | | the retina back together. Lasers are also used to |
| The word laser stands for Light Amplification by the | | | | correct poor vision by reshaping the cornea. One of |
| Stimulation Emission of Radiation. In 1916, Albert Einstein | | | | the newest medical uses for lasers is to make small |
| developed the theory of Stimulated Emission. Simply | | | | holes in the heart so that pathways are created for |
| put, it is a process where a photon is emitted from an | | | | new blood flow. This helps prevent heart attacks. The |
| atom and crashed into other atoms, causing them to | | | | only downside is the increased cost over traditional |
| also emit photons. In a vacuum chamber, more and | | | | surgeries. |
| more photons bounce around, raising the energy level | | | | Argon lasers make holograms, and are used in |
| within the chamber. When the energy has built up | | | | spectrochemistry, optical image processing, |
| sufficiently, it exits the chamber as a narrow beam of | | | | semiconductor processing and laser light shows. |
| light. Although Einstein's work was explored during the | | | | Solid state lasers |
| 1920s, it was largely forgotten until, in 1954, Charles | | | | Solid state lasers are used for cutting, welding, heat |
| Townes, an American physicist, started investigating | | | | treating and marking of materials. Jewelers can do |
| microwave light. | | | | very precise cuts when using lasers to cut fine gems. |
| The 60s heralded new breakthroughs in laser | | | | Lasers allow better cuts on metals and the welding of |
| technology. Theodore Maiman built the first working | | | | dissimilar metals. |
| optical light laser in 1960. It used a solid state laser that | | | | Scientists use solid state lasers to detect the slightest |
| incorporated a synthetic ruby. The first semiconductor | | | | movements in matter. Law enforcement has long |
| laser was developed in 1962. | | | | used laser technology for gauging the speed of cars. |
| Today, the three most common lasers are gas, solid | | | | The military is using solid state lasers in rangefinders, |
| state and semiconductor. | | | | laser guided bombs and satellite communications |
| Helium-neon lasers | | | | systems. |
| Helium-neon lasers are the cheapest visible light lasers. | | | | The largest lasers in the world are solid state lasers. |
| In 1974, they were used as bar code scanners, first in | | | | Many of the laser projectors for light shows and for |
| grocery stores and now in many large retail stores. | | | | other laser displays use solid state rather than argon |
| The laser is scanned across a bar code and tells the | | | | or krypton gas lasers. |
| cash register's computer the price of the item. It can | | | | Semiconductor lasers |
| also provide information on sale discounts, stock | | | | Semiconductors are used to produce lasers with |
| numbers and inventory. | | | | invisible light. The first successful consumer product to |
| Lasers are used by surveyors and machinists to | | | | include a laser, the laserdisc player, was introduced in |
| measure distance and align parts. They are used to | | | | 1978. In 1983, the compact disc player was introduced. |
| measure the speed of light in a laboratory, distances | | | | Currently, lasers are also used in DVD players, cellular |
| on a street or movement along an earthquake fault. | | | | phones, laser printers and wireless Internet |
| Argon lasers | | | | transmission. |