26 Jun An Advance May Double the Capabilities of Fiber Optics
Researchers have announced an advance that could double the capacity of fiber-optic circuits, potentially opening the way for networks to carry more data over long distances while significantly reducing their cost.
Writing in the journal Science on Thursday, electrical engineers at the University of California, San Diego proposed a way to extend the range that beams of laser light in fiber-optic glass wires can travel and, in theory, achieve that dramatic improvement.
One way to understand the challenge of sending data through fiber-optic circuits is to imagine a person shouting to someone else down a long corridor. As the listener moves farther away, the words become fainter and more difficult to discern as they echo off the walls.
A similar challenge confronts the designers of networks that carry data. Beams of laser light packed densely in fiber-optic glass wires need to be both amplified and recreated at regular intervals to send them thousands of miles. The process of converting the optical ones from light to electricity and then back again roughly every 60 miles is a significant part of the cost of these networks. The process also limits how much data they can carry.
In its report, the group described a way to “predistort” the data that is transmitted via laser beams so that it can be deciphered easily over great distances.
This is done by creating, in effect, guardrails for the light beams with a device known as a frequency comb — using very precise and evenly spaced signals — to encode the information before it is transmitted.
That has the effect of embedding a digital watermark in the original data, making it possible to transmit data accurately over much longer distances and dispense with the need to perform optical-to-electronic conversions at relatively short intervals.
Read full article>>