John MacChesney, optical pioneer
John MacChesney (Courtesy Alcatel-Lucent)
In the early 1970s, Bell Laboratories research engineer John MacChesney shifted a decade-long focus on the electrical and magnetic properties of ceramics and single crystals to a single material: glass. Researchers knew that light pulses, or photons, could be used to carry digital information, but the best material to transport that information hadn't been found.
MacChesney, working with colleague P.B. O'Connor, developed the Modified Chemical Vapor Deposition (MCVD) process, a way to fuse silica so that it achieved the level of purity and the configuration needed to create optical fibers.
"With MCVD, the required glass purity is achieved by heating chemical vapors and oxygen in the protected environment of a silica glass tube. Ultra-transparent glass deposited on the wall of the tube forms the higher-refractive-index core of the eventual fiber. The tube is collapsed into a solid and the finished glass rod, or preform, is later heated to temperatures in excess of 2,000 degrees Centigrade to stretch the glass to the thinness of a strand of human hair." (Alcatel-Lucent press release, 1999)
MacChesney's groundbreaking work on the manufacture of photonic components resulted in more than 100 domestic and foreign patents. Significantly, he extended his research on next-generation optical components to finding ways to use rare-earth materials like erbium to amplify optical signals. He also co-invented a high-purity overcladding for optical fiber, known as sol-gel, in the early 1980s--a process which allowed for the manufacture of large silica bodies.