Achivements of Robert Hall
Robert
Hall invented the version of the magnetron that operates most
microwave ovens, the semiconductor laser found in compact disk players,
and power rectifiers that greatly improved power transmission efficiency.
His basic rectifier structure, with silicon replacing the germanium, is used today for AC-to-DC power conversion in electric locomotives and high-voltage DC electrical transmission. In 1962 Hall invented the semiconductor injection laser, a device now used in all compact disk players and laser printers, and most optical fiber communications systems.
A
schematic diagram of Hall’s early concept for an injection laser
is shown in Figure. The first verification of laser operation was made
through the observation of the near and far-field interference patterns
using an infrared up converting “snooper scope” which was
being used in Hall’s lab to study the emission from such infrared
light emitters.