Year of Invention: 1957
What Is It? A machine that produces a high-energy light beam at the same ex-
Who Invented It? Gordon Gould (in Long Island, New York)
Supermarket checkouts rely on laser beams to scan your purchases. So do almost all retail stores in the Western world. Many eye surgeries are routinely performed using lasers. Communication systems pack thousands of voice channels on laser beam carriers. Engineers and construction crews make extensive use of lasers. Lasers read compact disks. They manufacture surgical cutting tools. There are few aspects of modern life that are not touched by lasers.
Lasers were not a direct replacement for any previously existing technology. People managed without. Checkout clerks punched codes and amounts into cash registers by hand. Levels and lines of sight were checked with light scopes and human eyes. Knives held by human hands performed cutting.
Charles Townes first created the theory and idea that led to lasers. He was struck with a powerful vision during a midnight stroll in the spring of 1951 while attending a Washington, D.C., conference called by the Office of Naval Intelligence. Conference attendees were searching for a way to generate higher frequency (shorter wavelength) radio signals. He couldn’t sleep and decided a midnight wander might clear his head. Sitting on a park bench, he realized that, if they were ever going to produce signals with microscopically small wavelengths, then instead of using bulky vacuum tubes, they would have to use atoms (the smallest device known) to produce those wavelengths. That idea led to lasers.
In 1917 Albert Einstein predicted that stimulated atoms would emit photons—particles of light energy. Townes decided to use blasts of microwave radiation to stimulate atoms into emitting streams of photons. Townes called his 1953 creation a maser (Microwave