Henk Wymeersch
​Henk Wymeersch is the leader of a research team that aims at quantifying and demonstrating the fundamental limits of fiber-optical communications.​​​​​​

Towards the full-dimensional fiber capacity

​How can the optical fibers that make up today’s Internet be used more effectively? This is going to be investigated by a group of researchers from Chalmers University of Technology in a five-year project. Their research is working toward a scientific breakthrough in the field of optical communication, for which they now have been granted SEK 30.7 million from the Knut and Alice Wallenberg Foundation.
The backbone of the Internet consists of hundreds of thousands of kilometers of optical fiber, in which enormous amounts of data are transferred around the globe. The demand for data seems to be insatiable and new applications connected to virtual reality (VR), big data, and Internet of things (IoT) are continuously adding to this. While the demand is increasing, the transmission capacity of optical fibers is limited. Moreover, installing and maintaining new fibers is costly and time-consuming. 

“We claim that the optical fibers are vastly underutilized today”, says Professor Henk Wymeersch, leader of the research team. “Our goal is to quantify and demonstrate the fundamental limits of fiber-optical communications. We will address a number of scientific questions ranging from fundamental theory and modeling to component design and integration.”

Coordination is key
In the design of the current transmission schemes, coupling among the physical dimensions of the optical transmission – notably polarization, space, and frequency – is not taken into consideration when transmitting data. Current approaches rely on accessing the physical dimensions separately, while a joint design would allow for more data to be sent over the same physical dimensions. 

Henk Wymeersch describes this using an analogy with cars driving on multiple lanes:

“If the cars are not coordinated at all, traffic jams and accidents inevitably will occur, that will slow down the traffic and delay everybody in reaching their destination. Similarly, the traffic flow in optical fibers is optimal when the transferred data is coordinated and adjusted across all physical dimensions.”

“Comparatively little research has previously been conducted in the field of coordinated transmission in fiber optical communication”, Henk Wymeersch says. “The focus has been on the nonlinear high-power regime, while the linear coordinated regime has come back to the forefront, due to recent technological advances, including multi-mode fibers and optical frequency combs. These have made it possible to now move into this direction.” 

The granted money from the Knut and Alice Wallenberg Foundation will be used to obtain the necessary equipment for the experimental part of the project, and to extend the research team, currently consisting of six Chalmers researchers, with about six additional researchers. Collaboration with industry will also play an important role in the project.

Lower costs and higher capacity
Not only will this project lead to new and fundamental understanding of transmission over optical fibers, there will be a major cost reduction for society if the present fiber optic links can be utilized more effectively. The knowledge gained in this project can also be transferred to other applications, for example spectroscopy and fiber imaging. Moreover, the work has impact in wireless communications as well, as wireless and optical communications converge. 

“Quantifying and demonstrating the fundamental limits of fiber-optical communications would imply a new era in this field. If we succeed in this, our scientific results will change how current and future fiber-optical communication systems are used and designed”, Henk Wymeersch concludes. 

The looming “capacity crunch” on the Internet would thus be overcome, or at least postponed.

Text: Yvonne Jonsson
Photo: Johan Bodell

About the project
Title: Unlocking the full-dimensional fiber capacity
Research team:
Henk Wymeersch​, Professor at the department of Electrical Engineering, Chalmers
Erik Agrell, Professor at the department of Electrical Engineering, Chalmers
Peter Andrekson, Professor at the department of Microtechnology and Nanoscience, Chalmers
Magnus Karlsson, Professor at the department of Microtechnology and Nanoscience, Chalmers
Jochen Schröder, Senior researcher at the department of Microtechnology and Nanoscience, Chalmers
Victor Torres Company​, Associate Professor at the Department of Microtechnology and Nanoscience, Chalmers
Grant: SEK 30.7 million over five years

The Knut and Alice Wallenberg Foundation is Sweden's largest private financier of research. In October 2018, the foundation allocates 22 grants for research projects deemed to maintain a high international standard and to have the potential to lead to future scientific breakthroughs. The grants, SEK 640 Million in total, will go towards basic research in medicine, technology and science.

Published: Tue 02 Oct 2018. Modified: Tue 02 Oct 2018