Fiber optic cables form the backbone of modern communication. They transport data across oceans, continents and cities, enabling the speed and availability of today’s internet. The development of classic optical fibres with a solid glass core has been continuously optimized since the 1980s, but this technology is now reaching its physical limits. A research team from the University of Southampton in collaboration with Microsoft Azure Fiber is now showing that a radically different construction method opens up completely new possibilities.
Source: futurezone.at
The newly developed fibers no longer have a continuous glass core, but are hollow on the inside. The light therefore moves through an air channel that is enclosed by a special glass structure. This “straw” design has several advantages. Firstly, light moves faster in air than in glass, which significantly increases the theoretical transmission speed. Secondly, the signal loss is significantly reduced so that data can be sent over longer distances without having to be amplified in between.
Another advantage is the variety of wavelengths. While conventional optical fibers work efficiently primarily in the infrared range, the new hollow fibers can use a broader spectrum. This means that several data channels can be transported simultaneously and in parallel through the same cable. The result is a significantly higher data capacity overall.
However, the production of these new cables is much more complex than that of standard fibers. Normally, a glass rod is heated and drawn to the desired thickness. With hollow fibers, however, several silicon tubes are stacked inside one another – usually five outer tubes, each containing two smaller tubes. This construction is surrounded by a cladding tube, which initially has a diameter of around 20 centimeters. During the drawing process, the whole thing is reduced to just 100 micrometers. To ensure that the filigree structure remains stable, each individual tube is pressurized.
The start-up Lumensity, a spin-off project from Southampton University that was acquired by Microsoft in 2022, is responsible for production. The aim is to secure the necessary expertise for potential industrial implementation.
The practical implications could be considerable. Traditional fiber optic cables lose around half of the transmitted light after around 15 to 20 kilometers. This is why millions of amplification stations are currently in use around the world, which process the signal again. With the new hollow fibers, these distances could be significantly increased, reducing the number of amplifiers. This would not only make the network infrastructure cheaper, but also reduce energy consumption.
But the hurdle is the cost. While conventional optical fibers cost just a few cents per meter, experts say that the new hollow fibers currently cost between 500 and 1,000 euros per meter. This means that large-scale application is not realistic at present. Michael Frosz from the Max Planck Institute for the Science of Light emphasizes that it could still take many years before production is possible on a scale that allows widespread use.
Conclusion
The new fiber optic cables with their “straw” design make it clear that the development of optical data transmission is far from complete. With their almost lightning-fast speed, lower losses and higher capacity, they could form the basis for an even faster and more efficient Internet in the future. At the same time, the technology remains a research project for the time being due to the immense manufacturing costs. Only when production processes are simplified and prices fall could it make the leap into practice and permanently change the current infrastructure.
Source: futurezone.at