In a promising breakthrough for the future of communications, EPFL researchers have developed a technology that can amplify light into the latest hollow optical fibers.
“The idea had been going around my head for about 15 years, but I never had the time or resources to do anything about it,” says Luc Thévenaz, head of the Fiber Optics Group at the EPFL School of Engineering. Now, his lab has developed a technology to amplify light within the latest hollow optical fibers.
By sucking the circle
Today’s optical fibers usually have a rigid glassless airless core inside. Light can travel along fibers but loses half its intensity after 15 kilometers. It continues to weaken until it is hardly detected at 300 miles. So to keep the light moving, it needs to be amplified at regular intervals.
Thévenaz approach is based on new depleted optical fibers that are filled with air or gas. “Air means there is less attenuation, so light can travel longer distances. This is a real advantage,” says the professor. But in a substance as thin as air, light is harder to amplify. “This is the crux of the problem: Light travels faster when there is less resistance, but at the same time it is more difficult to operate. Fortunately, our discovery has squared it around.”
From infrared to ultraviolet
So what did the researchers do? “We just increased the air pressure in the fibers to give us a controlled resistance,” explains Fan Yang, a postdoctoral student. “It works in a similar way to optical tweezers – air molecules are compressed and formed into regular groups in space. This creates a sound wave that rises in amplitudes and effectively scatters light from a powerful source to the beam. weakened in order to amplify up to 100,000 times “. Therefore their technique makes light significantly more powerful. “Our technology can be applied to any type of light, from infrared to ultraviolet and to any gas,” he explains. Their findings have just been published in Nature photonics.
An extremely accurate thermometer
Moving forward, the technology could serve purposes other than light amplification. Narrow or compressed core optical fibers, for example, can be used to make thermometers extremely accurate. “We will be able to measure the temperature distribution at every point along the fiber. So if a fire starts along a tunnel, we will know exactly where it started based on the increased temperature at a certain point,” says Flavien Gyger , Ph .D. student. The technology can also be used to create a temporary optical memory by stopping light on the fiber for a microsecond – this is ten times longer than is currently possible.
Performance space looks at narrow-core fiber technology in main fiber optics
Brillouin intensive gas amplification using hollow wave bands, Nature photonics (2020). DOI: 10.1038 / s41566-020-0676-z, www.nature.com/articles/s41566-020-0676-z
Provided by the Ecole Polytechnique Federale de Lausanne
citation: Use of air for light amplification (2020, August 10) Retrieved 11 August 2020 from https://phys.org/news/2020-08-air-amplify.html
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