Robert Noel Hall (December 25, 1919 – November 7, 2016) was an American engineer and applied physicist. He demonstrated the first semiconductor laser and invented a type of magnetron commonly used in microwave ovens. He also contributed to the development of rectifiers for power transmission.
Biography
Robert N. Hall was born on December 25, 1919, in New Haven, Connecticut. He was first inspired by his inventor uncle, who showed him the wonders of small inventions and experimentation. After long studies at his local library, Hall decided to attempt controlled experiments of his own with his mother's approval. He built an 8-inch telescope, which produced a close-up view of Saturn. Later on, an interviewer from the California Institute of Technology visited him and offered a scholarship to attend the university. Hall studied there for three years but had to leave for financial reasons. After working at Lockheed Aircraft as a tester, he returned to Caltech to finish up his studies and obtain his physics degree. Then General Electric hired him as a test engineer at Schenectady, NY. After four years at G.E., under the advice of Harper North, Hall obtained a Research Council Fellowship and returned to Caltech. He graduated in 1948 with his Ph.D. and returned to G.E. Schenectady research labs that summer.[1][2]
While at G.E. during World War II, he developed a magnetron for radar jamming, which led to the development of the microwave oven.[3]