The combination of spontaneous emission first, and then stimulated emission, causes the laser to "lase," which means it generates a coherent beam of light at a single frequency.
Who Invented It? In 1957, the laser was conceived by Gordon Gould, a graduate student in physics at Columbia University. When Gould filed for patents in 1959, he found that Columbia professor Charles Townes and Arthur Schawlow of Bell Labs had already filed for them. The year before, AT&T had, in fact, demonstrated a working laser at Bell Labs. In 1977, after years of litigation, a court awarded Gould rights to the first of three patents and later to all of them. He finally reaped millions in royalties.
Developing the Laser
This photo of the development of the helium-neon laser was taken at AT&T's Bell Laboratories in 1964. (Image courtesy of AT&T.)
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