Fiber Optics Transmission DistanceDecember 26th Fact-of-the-Day
Several factors control the distance information can be transmitted down a fiber optics line. Light signal attenuation is an obvious factor. Some light leaks out of glass fibers and some is absorbed by the glass, so the further light travels down a line the weaker it becomes. At some distance it becomes too weak to detect. Attenuation can be offset by higher light transmitting power, but high-power light transmitters are more expensive and tend to have narrower bandwidths. Pulse dispersion is another distance-limiting factor that is less-obvious. Light reflections off the inner walls of glass fibers cause light pulses to spread-out and increasingly overlap as they propagate down a line. That has the effect of reducing the transmission bandwidth. Consequently, the longer a fiber optics line is, the narrower its bandwidth is. At some length its bandwidth becomes too narrow to meet communication needs. ©2004 Martek International All rights reserved.
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