Lasers The first laser was described in California in 1957.In that year Dr. CharlesTownes and Dr. A. L. Schawlaw wrote articles explaining the way lasers should work .They didn't build one because just the right equipment was needed and they did not have it.Eventually the equipment was developed. Lasers are used for many things and here are some of the things they are used for.1) at a checking counter lasers read the bar codes called UPC's. 2) a laser is in the video disk player you may use to watch movies at home that you enjoy. 3) some types of metal can be laser -cut. 4) inner-ear surgey is usually done with an organ laser.5) lasers can also perform eye and skin surgey. 6) powerful laser beam cut steal tubing. 7) lasers can make hologram and 3-D pictures. There are also many other ways that lasers can be helpful (Laser Tag). Laser light is produced as a very narrow beam in a very parallel line with pure color. A typical laser has three main parts 1)An active medium - a material that can be made to create laser light 2) An engery source -amy type of device that can supplies energy to an active medium in a process called pumping. 3) Optical cavity -also called a resonator is a structure that encloses the active medium. There are seven typesof lasers:solid -state lasers,liquid lasers,dye lasers and gas discharge lasers,chemical lasers,semiconductor lasers |