Fiber communications turn 40

Several years after the first laser was demonstrated in 1960 another watershed event occurred in the development of photonics as we know it today. Two young research engineers from the Standard Telecommunications Laboratories in England presented a paper early in 1966 at the Institute of Electrical Engineers suggesting that transmission of information over optical fiber could be made a practical reality. Charles Kuen Kao and George Hockham suggested that losses in the optical fiber of the time were not an inherent property of the glass, but were in fact due to impurities in the material. It’s one of those ideas that seems obvious today but was groundbreaking back then. Fast-forward 40 years and much of the fabric of today’s global communications infrastructure is woven from modern optical fiber. Among the multitude of fiber-related developments since Kao and Hockman’s paper has been the emergence of plastic optical fiber (POF)-a lower-cost fiber for low-speed, short-distance (consumer) applications. Today the use of POF in automobiles is fast gaining momentum as emerging vehicle designs incorporate multimedia data networks to meet the latest control, safety, and entertainment needs (see p. 57).

Novel techniques speed optics testing

The performance of any optical system depends on the quality of the optical media involved. Learning to eliminate impurities from the glass used to make optical fibers, for instance, has improved fiber performance to the point that specialty fibers can now be tailored to specific applications. In many other optical arenas the fabrication of quality optical media has been well understood for some time, but the increasing need to test or characterize those optics en masse and economically presents an entirely different challenge. A nontraditional approach to inline modulation-transfer-function (MTF) testing speeds production of well-characterized lens assemblies for high-volume applications (see cover and p. 49).