LumiSync: photonics for next-generation data centres

In 2017, at the Centre for Nanoscience and Nanotechnology (C2N), Giuseppe Bravo Modica, now Chief Technology Officer (CTO) of LumiSync, began his thesis under the supervision of Rémi Braive, a lecturer specialising in optical materials and interactions and today the company's Chief Scientific Officer (CSO). Together, they explored a new kind of photonic oscillator, a device capable of generating ultra-stable, ultra-fast light signals.

In June 2022, their results were convincing enough to secure two years of prematuration funding from CNRS Innovation, the CNRS' national structure for technology transfer and commercialisation. This led to an initial proof of concept (PoC) demonstrating the project's technological feasibility. At the same time, in 2023, the pair joined the RISE programme, an entrepreneurial support scheme run by the same organisation. There they met Alexis Jonville, then an entrepreneur-in-residence and now CEO of LumiSync. An engineering graduate from ESPCI Paris (École supérieure de physique et de chimie industrielles de la ville de Paris - Higher School of Industrial Physics and Chemistry of the City of Paris), he completed research internships at the Massachusetts Institute of Technology (MIT) and IBM in Silicon Valley, before earning a double degree at HEC. "I wanted to put my hybrid background in both science and business to work on a groundbreaking technology project." He joined LumiSync full-time in April 2024.

A promising market environment

The project comes at a time when artificial intelligence is exploding and demand for data processing is increasing. Today, digital infrastructures account for around 3% of global CO₂ emissions, a share that could rise to 10% by 2030 if current technologies remain dominant. "Electronics have reached their limits after more than 70 years of continuous improvement. Making electronic systems faster inevitably means consuming far more energy."

LumiSync stands apart from the three main types of solutions currently on the market. Crystal oscillators, the long-standing dominant technology, can no longer keep pace with modern flow rates without overheating. Hybrid optoelectronic architectures offer an improvement, but remain constrained by their electronic components. Other players are exploring a third way, namely optical synchronisation using electronic oscillators, but this merely sidesteps the problem. LumiSync's radical innovation eliminates electronics from the synchronisation chain altogether.

The photonic oscillator: a world first

Photonics transmits information in the form of light signals through optical fibres, rather than as electrical currents through copper wires. This provides two major advantages: processing at the speed of light, and a drastic reduction in energy consumption, since generating light requires less energy than producing electric current.

LumiSync applies this photonic principle to a key component in computing systems, the oscillator, which ensures that every component in a network shares the same information at the same time. In a next-generation data centre, with several tens of thousands of servers handling throughput of 1.6 terabits per second or more, it guarantees server coherence and smooth, real-time operation. The accuracy of this synchronisation determines computing speed, reliability of data exchange and security. "We're doing with light what electronics do today with current, but at the speed of light."

Three patent families protect this technology: the oscillator design, the manufacturing protocol and the creation of photonic synchronisation networks.

A well-structured support ecosystem

LumiSync is rooted in a robust scientific and technological environment. Based at C2N in Palaiseau (Essonne), the team has direct access to the Plateau de Saclay's micro- and nanofabrication facilities, which are essential for producing its oscillators. In early 2025, the Paris-Saclay Technology Transfer Accelerator Office (SATT Paris-Saclay), which negotiates patent licenses on behalf of CNRS, finalised the transfer of intellectual property to the start-up. It also funded two engineers for the project as part of the maturation phase. This institutional framework is facilitating LumiSync's transition from laboratory to company.

Since 2024, the start-up has been supported by IncubAlliance, the public research incubator for the Paris-Saclay cluster, which has helped it structure its strategy and win the BPI France i-Lab 2025 innovation competition. It also benefits from the support of 21st, the CentraleSupélec accelerator, and the DataIA chair, which is fostering exchanges with the Taiwanese semiconductor ecosystem.

In 2024, LumiSync was recognised in the Spring 50 pitch competition at the Spring Paris-Saclay trade show, and in 2025, it was a finalist for the Innovation of the Year award at VivaTech, the annual international innovation event in Paris.

The critical scale-up stage

LumiSync's technology currently stands at a Technology Readiness Level (TRL) of between 4 and 5. This scale, developed by NASA, measures the maturity of a technology from the initial concept (TRL 1) to industrialised product (TRL 9). At this stage, LumiSync has a laboratory-validated prototype. "We're now in what is known as the valley of death for technology start-ups. That's the stage where substantial resources are needed to turn a laboratory prototype into an industrial product." To tackle this stage, alongside the financing already secured, the team is preparing a €3-million funding round by the end of 2025. In addition, it is beginning to recruit R&D and product engineers, to strengthen its technological development capacity.

Industrial strategy and ambitions

Discussions are currently underway with several major server component integrators in Europe, Asia and the United States. The aim is to co-develop industrial prototypes for testing in real-world conditions from 2026 (TRL 6), followed by pilot integrations within next-generation server architectures in 2027 (TRL 7). LumiSync wants to work closely with companies to test its technology by integrating it into their existing architectures, demonstrating its functionality and the promised added value, before gradually scaling up. "Our project proves that long-term academic research can lead to a technology that's strategic for both industry and the planet. We're proud to offer a game-changing innovation in terms of performance and energy efficiency."