Researchers have set a new speed record for an industry standard optical fiber, achieving 1.7 Petabits over a 67 km length of fiber. The fiber, which contains 19 cores that can each carry a signal, meets the global standards for fiber size ensuring that it can be adopted without massive infrastructure change.
The 19-core optical fiber. Image credit: Rademacher et al., doi: 10.1364/OFC.2023.Th4A.4. Flat Drop Fiber Cable
All the world’s internet traffic is carried through optical fibers which are each 125 microns thick.
These industry standard fibers link continents, data centers, mobile phone towers, satellite ground stations and our homes and businesses.
Back in 1988, the first subsea fiber-optic cable across the Atlantic had a capacity of 20 Megabits or 40,000 telephone calls, in two pairs of fibers. Known as TAT 8, it came just in time to support the development of the World Wide Web. But it was soon at capacity.
The latest generation of subsea cables such as the Grace Hopper cable, which went into service in 2022, carries 22 Terabits in each of 16 fiber pairs. That’s a million times more capacity than TAT 8.
But it’s still not enough to meet the demand for streaming TV, video conferencing and all our other global communication.
“Decades of optics research around the world has allowed the industry to push more and more data through single fibers,” said Macquarie University researcher Simon Gross.
“They’ve used different colors, different polarizations, light coherence and many other tricks to manipulate light.”
Most current fibers have a single core that carries multiple light signals. But this current technology is practically limited to only a few Terabits per second due to interference between the signals.
“We could increase capacity by using thicker fibers,” Dr. Gross said.
“But thicker fibers would be less flexible, more fragile, less suitable for long-haul cables, and would require massive reengineering of optical fiber infrastructure.”
“We could just add more fibers. But each fiber adds equipment overhead and cost, and we’d need a lot more fibers.”
To meet the exponentially growing demand for movement of data, telecommunication companies need technologies that offer greater data flow for reduced cost.
The newly-developed fiber contains 19 cores that can each carry a signal.
“We’ve created a compact glass chip with a wave guide pattern etched into it by a 3D laser printing technology,” Dr. Gross said.
“It allows feeding of signals into the 19 individual cores of the fiber simultaneously with uniform low losses.”
“Other approaches are lossy and limited in the number of cores.”
The authors presented their results in March 2023 at the Optical Fiber Communication Conference (OFC) 2023 in San Diego, California, the United States.
Fiber Optic Cable Armored Georg Rademacher et al. 2023. Randomly Coupled 19-Core Multi-Core Fiber with Standard Cladding Diameter. OFC 2023, paper # Th4A.4; doi: 10.1364/OFC.2023.Th4A.4