Yuan Lu: How will SpinDataCom transform space communications?

This ambitious project, which brings together academic and industrial partners from four European countries, aims to revolutionize terrestrial and space communications by combining spintronics and semiconductor lasers. With potential applications ranging from improving GPS services to reducing energy consumption in data centers, SpinDataCom is paving the way for a new era in communications technology. Yuan Lu reveals the stakes, challenges and prospects of this extraordinary scientific adventure.

Can you explain to us, in simple terms, what spintronics is and why it’s important for terrestrial and space communications?

Spintronics is a cutting-edge field that looks at how the tiny magnetic properties of electrons, called "spin”, interact with electrical charge. Thinking of electrons like tiny magnets—they have both a charge and a spin, which can be thought of as pointing "up" or "down”. Spintronics studies how this spin affects the electricity when moving through materials.

We usually send information using light in optical communication, and the current mainstream technology modulates light intensity to transmit data. This method uses a lot of energy. Spintronics can help us send data by modulating the circular polarization of light*, which consumes much less energy. This could make data transmission much faster and more efficient, particularly over long distances, like between Earth and Mars. Even when only a few photons reach us, their polarization could still carry important information.

*It represents the rotation direction of the electrical component of light (clockwise or counterclockwise) around its propagation axis.

What is the main goal of this project, and how could it change the way we communicate?

Our project, SpinDataCom, is aiming to develop a new type of laser that can quickly change the polarization of light. This would allow for faster, more efficient data transmission on Earth and in space. By using a technique called the spin-Hall effect, we can electrically control the magnetic properties of a special injector layer on top of lasers, which changes the spin of the electrons injected in the laser. This change in spin affects the light’s polarization, allowing us to transmit data at very high speeds.

Why is this project particularly innovative compared to current technologies?

Current technology relies on changing light intensity to send information, but this has limitations in speed and energy use. Our method, which modulates light’s polarization instead, allows for much faster speeds—up to 1 terahertz (THz), or 1,000 GHz. Plus, our system uses far less energy because the light’s intensity stays the same, no matter how fast we modulate the polarization. This makes our approach up to 10 times more energy-efficient than conventional lasers.

Can you give concrete examples of how this technology could benefit society, like in GPS or data centers?

This technology could greatly improve GPS accuracy, making it possible to locate devices even indoors. It could also enhance the speed of data transmission between satellites and on the ground. For example, satellites currently communicate at speeds of a few gigahertz (GHz), but with our spin-laser technology, we could increase that speed 100 times. This would reduce the need for numerous satellites and help in managing space debris. In data centers, this faster communication could lead to much lower energy use and cooling costs, while supporting the growing demand for internet services.

What are the main scientific or technical challenges you expect in this project?

There are three big challenges:

• We need to figure out how to control the polarization of light efficiently using spin.
• We have to make sure this control can happen at very fast speeds, so we’ll need to engineer the laser’s components carefully.
• Finally, we’ll study how fast we can modulate the light’s polarization to understand any speed limits.

How could this project help with environmental issues like reducing energy consumption in data centers?

Data centers use a huge amount of energy : by 2030, they could consume 8% of the world’s electricity. Our spin-lasers use up to 10 times less power than current lasers while still transmitting data faster. This means data centers will need less cooling and consume less power, reducing their overall environmental impact.

What’s the importance of working with industry partners like Thales?

Collaborating with industry is crucial because it helps turn our scientific discoveries into real-world applications. For example, Thales Research & Technology will help us develop spin-laser systems that could be used in space communication. Another partner, VIS (Vertical Integrated Systems, Germany), will focus on adapting our technology for use in data centers. These partnerships ensure our work has a clear path from the lab to the marketplace.

What could be the first practical application of this technology in daily life?

The first practical application would likely be in data centers. Our lasers, which are faster and more energy-efficient, could improve the way servers communicate with each other. This would make data centers more efficient and lower energy costs.

How do you see this field evolving after the project is completed?

By the end of the project, we aim to have developed a prototype of our spin-laser technology. This will allow us to start working with customers, fine-tuning the electronics, and establishing standards for the technology. These are key steps to bringing our innovation to the wider market.

What message would you like to share with the general public about the importance of fundamental research for innovations like this?

Fundamental research is essential for breakthroughs in technology. It often takes years of work to turn a scientific concept into something that can be used in the real world. For example, we’ve been working on the concept of spin-LED for over 15 years, and only now we are ready to bring it to practical applications. Projects like SpinDataCom show how important fundamental research is in driving technological progress that can benefit society.

Would you like to add anything else ? 

Yes. I greatly appreciate the help from CNRS SPV in building this project. Our proposal has been submitted three times: the first two by Typhanie Roy (Alsace Delegation), and the third by Oriane Marchal and Justine Rietsch (Centre-Est Delegation). Throughout the preparation process, we had many productive discussions that significantly improved the quality of the proposals. They also contributed excellent ideas, particularly regarding the impact section. I am also grateful for their assistance with all administrative tasks (filling in information on the website, contacting partners for the budget, etc.), which allowed me to focus on the scientific aspects. Without their hard work, this project would not have been possible.