General Electric (GE) engineer Nick Holonyak turned on the world’s first LED – which was red – 50 years ago. The laser was still a brand new technology back in February 1963, when Harland Manchester, a past president of the National Association of Science Writers, wrote about the technology’s many applications in the pages of Reader’s Digest. “The latest dramatic laser discoveries, made by General Electric, may someday make the electric light obsolete,” he wrote. “If these plans work out, the lamp of the future may be a speck of metal the size of a pencil-point which will be practically indestructible, will never burn out, and will convert at least 10 times as much current into light as does today’s bulb.” That “lamp of the future” is what we now call the light-emitting diode (LED). Manchester could make his prophesy because he interviewed GE physicist Nick Holonyak in 1962, 50 years ago this fall, about LED. Holonyak’s diode emitted only red light, but it lit a research boom that has led to multi-colored novelty string lights, commercial fixtures that illuminate homes and cities, the latest iPad “retina” screens, and flat-screen TVs. “Boy, those were the golden years,” says Holonyak, who is now 83 years old. “When I went in, I didn’t realize all that we were going to do. As far as I am concerned, the modern LED starts at GE.” Holonyak, whose parents immigrated from what is now western Ukraine, enrolled to study electrical engineering at the University of Illinois. He took a course in atomic physics with John Bardeen, and in 1951 became Bardeen’s first doctoral student in his new semiconductor laboratory. “This is where everything started,” Holonyak says. Just five years later, Bardeen shared the Nobel Prize in Physics with William Shockley and Walter Brattain for building the first semiconducting transistor. Holonyak continued his studies, earning a PhD. In 1957, after one year at Bell Labs and a two-year stint in the Army, he joined GE’s research lab in Syracuse, New York. GE was already exploring semiconductor applications and building the forerunners of modern diodes called thyristors and rectifiers. At a GE lab in Schenectady, the scientist Robert Hall was trying to build the first diode laser. Hall, Holonyak, and others noticed that semiconductors emit radiation, including visible light, when electricity flows through them. Holonyak and Hall were trying to “turn them on,” and channel, focus, and multiply the light. Hall was the first to succeed. He built the world’s first semiconductor laser. Without it, there would be no CD and DVD players today. “Nobody knew how to turn the semiconductor into the laser,” Holonyak says. “We arrived at the answer before anyone else.” Hall’s laser, however, emitted only invisible, infrared light. Holonyak spent more time in his lab, testing, cutting, and polishing his hand-made semiconducting alloys. In the fall of 1962, he got first light. “People thought that alloys were rough and turgid and lumpy,” he says. “We knew damn well what happened and that we had a very powerful way of converting electrical current directly into light. We had the ultimate lamp.”
