Lasers :: essays research papers

When mostpeople see a optical maser beam they be amazed by itsunique physical properties. Laser unprovoked is so uniquefrom other light because it is coherent unlikeordinary light, which travels in all directions, laserlight travels in a straight beam. The word laser isan acronym for Light Amplification by StimulatedEmission of Radiation. The history of the laser isvery interesting. Lasers have changed vastlysince they were first invented. Before the laser wasinvented, Charles Townes developed the maser in1954. The maser has basically the same principlesas the laser, but it involves microwaves instead oflight. The maser lead Theodore Maximan toassemble the first working laser in 1960 he didthis by applying the masers qualities to light. Thisfirst solid-state laser was a ruby crystal laser. Ayear after the first solid-state laser was invented,the first gas laser was constructed by Ali Javan,W. R. Bennett, and D. R. Herriot. This was ahelium-neon laser. The helium-neon laser is th emost common laser found today. Many othertypes of lasers have been invented since then the semiconducting material laser (1962), the chemical laser(1964), the liquid laser (1966), and the freeelectron laser (1977). All lasers work basically onthe same principles. First the atoms in thesubstance used are pumped. For example, thehelium and neon would be pumped in ahelium-neon laser. This is where the electrons ofthe atoms jump to higher orbitals, which havemore energy. The substance house be pumped byusing flashlamps, other lasers, atomic explosions,electric discharges, solar energy, and etc... Whenthe atoms are pumped, they perform stimulatedemission. This is where the electrons arestimulated by photons to use up coherent photonsof a single frequency and color. After the pumpingprocess, the oscillation process takes place. In thisprocess energy is amplified to make it strongerand more useful. This is done by peppy thephotons between two mirrors until they take place acertain int ensity. The two mirrors are one of 100percent efficiency and one of a lesser efficiency.When the photons reach the certain intensity, theyleave the mirror of lesser efficiency in a coherentbeam. There are basically four main types oflasers solid-state, gas, liquid, and semi-conductor.Solid-state lasers are made from a crystallinematerial such as ruby. The crystals have impuritiesin them that can be stimulated to release radiationin a coherent fashion. These impurities are neededto make the laser last for long periods of time. Ifthe crystals do not have impurities, then they canhave some added this is called "doping." Thecrystals in solid state lasers are usually pumped byusing flashlamps. Gas laser beams are much more