John Burnette MacChesney II (July 8, 1929 – September 30, 2021) was an American scientist.
A Bell Labs pioneer in optical communication, he was best known for his 1974 invention of the modified chemical vapor deposition (MCVD) process with colleague P.B.
In 1959 he received his Ph.D. in geochemistry from Pennsylvania State University, and joined Bell Labs, examining electrical and magnetic properties of ceramics and single crystals.
In 1972 he turned his attention to glass and then to erbium and other rare-earth materials for fiber optic amplifiers.
MacChesney was an adjunct professor at Brown and Rutgers universities, as well as the Kwangju Institute of Science and Technology in Korea, and held more than a hundred domestic and foreign patents.