By W. Bart Bielawski, Corning Glass Works
Low-loss waveguides are solid fibers of glass only 5 thousandths of an inch in diameter. Information is transferred over optical waveguides by appropriately modulating near infrared source such as an LED or laser and detecting the change in the output flux with a compatible solid-state detector such as PIN or avalanche photodiode. Measurements of such fiber waveguides in lengths over 3000 feet show total attenuation as low as 2 dB/km and bandwidth capability as high as 500 MHz in one Km length.
Transmission characteristics of optical waveguides are independent of operating frequency and temperature, promising relatively simple and reliable systems.
Corning expects to develop waveguide cables which will be cost competitive with coax on a per foot basis.
Availability of practical light sources and detectors limits current capability to construct useful systems. From the input/output devices' point of view, digital rather than analog operation would be preferred in most cases,