Ruby laser weaknesses in the lining. Ruby lasers were used extensively in tattoo and hair removal, but are being replaced by alexandrite and s in this application. The ruby laser was the first laser to be made functional. Built by Theodore Maiman in 1960, the device was created out of the concept of an "optical maser," a maser that could operate in the visual or infrared regions of the spectrum. In 1958, after the inventor of the maser, Charles Townes, and his colleague, Arthur Schawlow, published an article in the "Physical Review" regarding the idea of optical masers, the race to build
Laser tag range of ages. When compared to paintball, laser tag is painless because it uses no physical projectiles, and indoor versions may be considered less physically demanding because most indoor venues prohibit running or roughhousing. In late 1970s and early '80s, the United States Army deployed a system using infrared beams for combat training. The MILES system functions like laser tag in that beams are "fired" into receivers that score hits. Similar systems are now manufactured by several companies and used by various armed forces around the world. The first known toy to use infrared light and a corresponding sensor was