The world’s fastest industry standard optical fibre

Newswise — An optical cable, approximately as thin as a human hair, can presently transmit the equivalent data of over 10 million fully operational high-speed home internet connections.

A consortium of Japanese, Australian, Dutch, and Italian scientists has established a fresh velocity milestone for a conventional optical cable, attaining a data rate of 1.7 Petabits across a 67km span of fibre. This fibre, housing 19 cores capable of transmitting signals individually, complies with international fibre size regulations, allowing its implementation without extensive infrastructure modifications. Moreover, it employs reduced digital processing, resulting in a significant reduction in power consumption per transmitted bit.

The innovation was bolstered by the contributions of researchers from Macquarie University, who aided in the creation by developing a 3D laser-printed glass chip. This chip facilitates seamless and efficient access to the 19 light streams transmitted through the fibre, while also guaranteeing compatibility with current transmission equipment. Its design ensures minimal signal loss, enabling optimal performance of the system.

The optical fibre was jointly developed by the Japanese National Institute of Information and Communications Technology (NICT) and Sumitomo Electric Industries, Ltd. (SEI), both based in Japan. This collaborative effort involved the participation of Eindhoven University of Technology, University of L'Aquila, and Macquarie University, contributing their expertise to the project.

The entirety of global internet traffic relies on the transmission capabilities of optical fibres, which possess a thickness of 125 microns, akin to the width of a human hair. These widely adopted industry standard fibres serve as the vital link connecting continents, data centers, mobile phone towers, satellite ground stations, as well as our homes and businesses, enabling the seamless flow of information across vast distances.

In 1988, the inaugural transatlantic subsea fibre-optic cable, TAT 8, marked a significant milestone with its capacity to carry 20 Megabits of data or the equivalent of 40,000 telephone calls. This pioneering cable played a crucial role in facilitating the early growth of the World Wide Web. However, due to the rapid expansion of digital communication, TAT 8 quickly reached its maximum capacity, highlighting the escalating demand for increased data transmission capabilities.

The Grace Hopper cable, launched in 2022, represents the most recent advancement in subsea cables. This cutting-edge cable boasts an impressive capacity of 22 Terabits in each of its 16 fibre pairs. Comparatively, this capacity is a million times greater than that of the TAT 8 cable. Despite this significant leap forward, the escalating demand for services such as streaming TV, video conferencing, and other forms of global communication continues to outpace the available capacity. This highlights the ongoing need for further advancements in data transmission technology to meet the ever-growing demands of our interconnected world.

Dr. Simon Gross, an expert from Macquarie University's School of Engineering, acknowledges the significant advancements in data transmission through single fibres, which have been made possible by decades of global optics research. Researchers have employed various techniques such as leveraging different colors, polarizations, light coherence, and numerous other methods to manipulate light effectively. These innovative approaches have played a pivotal role in enabling the industry to continually increase the amount of data that can be transmitted through optical fibres.

Presently, the majority of fibres employ a solitary core for transmitting multiple light signals. However, this existing technology faces practical constraints and is effectively restricted to a mere few Terabits per second due to signal interference.

According to Dr. Gross, one potential approach to increase capacity is to utilize thicker fibres. However, this solution comes with its own set of challenges. Thicker fibres would be less flexible, more susceptible to damage, less suitable for long-distance cables, and would necessitate extensive reengineering of the existing optical fibre infrastructure. Therefore, while increasing the thickness of fibres may offer a potential capacity boost, it is accompanied by practical limitations and significant infrastructure considerations.

“We could just add more fibres. But each fibre adds equipment overhead and cost and we’d need a lot more fibres.”

In order to address the ever-increasing demand for data transfer, telecommunication companies require technologies that provide higher data throughput while simultaneously reducing costs.

The new fibre contains 19 cores that can each carry a signal.

Dr. Gross explains that Macquarie University has made significant progress in this area, developing a compact glass chip using 3D laser printing technology. This chip features a waveguide pattern etched into it, enabling the simultaneous feeding of signals into the 19 individual cores of the fibre. Importantly, this approach ensures uniform low losses, setting it apart from other methods that may suffer from signal degradation and limitations in the number of cores that can be utilized. The development of this innovative chip holds great promise for enhancing data transmission capabilities and overcoming existing limitations in fibre optic technology.

Collaborating with Japanese optical fibre technology leaders has been thrilling. My anticipation is that this technology will be incorporated into subsea cables within a span of five to 10 years.

Professor Michael Withford, who also participated in the experiment, emphasizes the far-reaching implications of this optical fibre technology breakthrough. With this advancement, the potential impact extends beyond the immediate application, opening up new possibilities and opportunities in various fields. This achievement represents a significant milestone in the evolution of optical fibre technology, laying the foundation for future advancements and innovations.

Professor Withford highlights that the optical chip developed builds upon decades of optical research conducted at Macquarie University. The underlying patented technology not only has implications for data transmission but also holds potential for various applications. These applications span a wide range, from detecting planets orbiting distant stars to disease detection and even identifying damage in sewage pipes. This signifies the versatility and diverse possibilities enabled by this breakthrough technology beyond its immediate use in optical fibre communication.

Measuring Internet speed

The velocity of an Internet connection is typically assessed in Megabits. The magnitude of a file is typically evaluated in Megabytes. There are eight Megabits equivalent to a Megabyte.

There are 1,000 Megabits in a Gigabit, 1,000 Gigabits in a Terabit, and 1,000 Terabits in a Petabit.

The majority of home NBN connections in Australia offer speeds ranging from 25 to 100 Megabits per second. However, with the introduction of fiber to the premises technology, one Gigabit per second is now available.

In Singapore, the average broadband connection speed is around 220 Megabits. In Japan, it is approximately 150 Megabits, while in the USA, the average speed is around 140 Megabits. On the other hand, Australia has an average broadband connection speed of about 75 Megabits.

The new fiber technology has been demonstrated to deliver a capacity of 1.7 Petabits over a 67 km length of fiber.

Abstract and authors

We developed a randomly-coupled 19-core fiber with standard 125-µm cladding diameter with spatial mode dispersion of 10.8ps/ √km, enabling a data rate of 1.7 Pb/s, the highest reported amongst optical fibers with standard cladding diameter.

Georg Rademacher,(1),* Menno van den Hout,(1),(2) Ruben S. Luís,(1) Benjamin J. Puttnam,(1) Giammarco Di Sciullo,(1),(3) Tetsuya Hayashi,(4) Ayumi Inoue,(4) Takuji Nagashima,(4) Simon Gross,(5) Andrew Ross-Adams,(6) Michael J. Withford,(6) Jun Sakaguchi,(1) Cristian Antonelli,(3) Chigo Okonkwo,(2) and Hideaki Furukawa(1)