The internet has a bit of an appetite problem. Every message you send, every show you stream, every file you upload travels as pulses of light through vast networks of optical fibres. It all feels effortless, but behind the scenes, it takes energy. A lot of it. And as our digital lives keep expanding, that energy demand is rising fast.
A research project called FOCUSED, led by Professor Leif Katsuo Oxenløwe, is taking a very different approach to this challenge. Instead of just improving today’s systems bit by bit, the project goes back to the laws of physics to ask a bold question: what is the absolute minimum amount of energy needed to send information?
Rethinking communication from the ground up
To answer that, the researchers draw on thermodynamics – the science of heat and energy. In the 19th century, scientists defined the Carnot heat engine, a theoretical machine that represents the most efficient possible way to convert energy into work. FOCUSED applies a similar idea to communication, imagining a “perfect” communication system that uses as little energy as the laws of physics allow.
This shifts the goalposts. Instead of asking how to make current technology slightly better, the project asks what ultimate efficiency looks like, and then works backward to design systems that approach it.
A surprising trick: split the data
One of the most unexpected insights is that sending data through many parallel channels can actually reduce total energy use. It sounds counterintuitive, but it works a bit like traffic: a single overcrowded lane wastes time and fuel, while multiple lanes keep things flowing smoothly.
In optical fibres, these lanes are different channels of light. By spreading data across them, the system can reduce the need for frequent signal boosting – one of the major sources of energy consumption in today’s networks.
One light source, massive capacity
To make this work in practice, the project explores advanced technologies such as optical frequency combs – light sources that produce many precise colours at once. Instead of using hundreds of separate lasers, a single comb can generate thousands of channels.
In earlier research, scientists showed that one such device could carry data at a rate of 1.8 petabits per second – enough, in principle, to handle the entire global internet traffic. It’s a striking demonstration of how much capacity can be packed into a single, well-designed system.
At the same time, FOCUSED works on improving amplifiers – the devices that keep signals strong as they travel through fibre cables. By reducing how many are needed, and making them more efficient, data could travel much longer distances without “recharging.” The project also develops tiny photonic chips that can process many channels of light at once, helping scale up capacity without scaling up energy use.
Why it matters
The stakes are bigger than faster downloads. The internet underpins everything from green energy systems and climate monitoring to healthcare and global communication. But if the internet itself becomes too energy-hungry, it undermines those benefits.
FOCUSED could:
- Cut the energy cost of global data traffic dramatically
- Enable future technologies like 6G networks
- Improve satellite communication and data centers
- Even support scientific tools like ultra-precise clocks and space sensors
What FOCUSED offers is not just a set of new components, but a new way of thinking. By designing communication systems around minimum energy use from the start, it opens the door to networks that are both more powerful and far more efficient.
If it succeeds, most people won’t notice anything different. The internet will feel just as fast, just as seamless. But behind the scenes, it could be running on a much leaner energy budget – a quiet but important step toward a more sustainable digital world.
