Semiconductor Laser


In September 1962 researchers from IBM, independently and almost simultaneously with researchers from General Electric and MIT's Lincoln Laboratory, demonstrated laser action in the semiconductor gallium arsenide.

General Electric researcher Robert Hall developed one of these lasers in 1962. After hearing a talk on the properties on highly-emitting diodes and gallium arsenide, he speculated that a semiconductor junction could emit a simpler and more focused laser. Hall had spent years working on semiconductor technology, having invented the “p-i-n” diode rectifier from purified germanium. This type of semiconductor proved integral to the development of solid-state semiconductors used in electrical transmission, as it could convert AC power to DC. Hall’s laser used a p-n junction semiconductor to generate light efficiently and from a very small crystal of one-third of a millimeter. Electrical current sent into the semiconductor junction, rather than a high-intensity light source, created the electrons.

Hall was among a cohort of ambitious scientists seeking to win the race to build the first semiconductor laser. Hall’s report of a coherent infrared emission from a semiconductor laser was published in the November 1, 1962 issue of Physical Review Letters. At the same time, Marshall Nathan’s research team at IBM’s Watson Research Labs and Ted Quist’s group at MIT’s Lincoln Labs were releasing reports of their own successful demonstrations of gallium arsenide lasers to the journal Applied Physics Letters.

As Nathan of IBM recalled, he was studying the photoluminescent properties of gallium arsenide early in 1962 when his department director decided his group would be the first to created a gallium arsenide laser. In February of 1962, Nathan began the effort through use of a flash lamp that would inject the semiconductor with light, but it did not create a coherent laser. By September 1962, however, Nathan’s team saw “spectacular line narrowing.” After hand-delivering this result to Applied Physics Letters, they pursued the finding and were able to achieve continuous-wave lasing.

By October 1962, IBM sent out its patent application, only to discover that GE had crossed the finish line eleven days before. The two organizations apparently had no idea they were in serious competition. GE and IBM would each obtain patents on this technology, except in Germany, where GE won the rights based on Hall’s design. Semiconductor injection lasers became critical components in digital media, used to read the data on CD and CD-ROM units, remote controls, and fiberoptic communications systems.