May 06, 2026 -- Fraunhofer is making hydrogen applications safer and more cost-effective: In the RADIANT joint project, Fraunhofer Institute for Microelectronic Circuits and Systems IMS, Fraunhofer Institute for Applied Solid State Physics IAF, and Fraunhofer Center for Applied Photonics CAP (Glasgow, UK) are developing a novel, compact Raman LiDAR system. It reliably detects gas leakages, particularly hydrogen, from a distance, even under challenging environmental conditions. For operators of energy facilities and industrial process environments, this means early detection without risk to personnel, continuous monitoring, and scalable solutions for real-world deployment.

The safe use of hydrogen is considered to be key to the energy transition, but it presents new challenges for industry and infrastructure operators. Hydrogen is colourless and odourless and exhibits virtually no optical absorption characteristics. Early, reliable detection of leaks from a safe distance is therefore essential, for example in power plants, production facilities, or pipelines.

Reliable gas detection from a distance, even in daylight

This is where Raman LiDAR technology comes into play: it uses the characteristic Raman scattering of molecules to uniquely identify various gases and precisely determine their position via time-of-flight measurements. The challenge lies in the weak optical signals, which are often in the single-photon range, particularly during outdoor measurements and in bright sunlight.

However, existing Raman LiDAR systems are often designed for only a few, predefined molecules. RADIANT (»Raman Atmospheric DetectIon And ranging Technology«) takes a new approach: the use of linear detector arrays is intended to replace the previous filter-based spectral separation. This allows for significantly greater molecular flexibility and paves the way for universal molecular detection. The system operates in the solar-blind UV-B and UV-C ranges. There solar background radiation is greatly reduced, enabling measurements in daylight and significantly increasing sensitivity.

Highly sensitive detectors for practical applications

In RADIANT, Fraunhofer IMS contributes its expertise in the development of back-illuminated silicon photomultipliers (BSI-SiPMs) with enhanced UV sensitivity. »The detectors are specifically optimized for the requirements of time-resolved Raman measurements and enable the detection of extremely weak signals while maintaining high temporal resolution,« explains Dr. Maren Kasischke, Head of Industry at Fraunhofer IMS.

A key development step is also the readout circuit for up to 32 channels, which allows for parallel and rapid processing of all spectroscopy signals. This makes it possible for the first time to acquire Raman spectra with high temporal and spectral resolution and to adapt them flexibly to different molecules.

As a scomplementary approach, Fraunhofer IAF is developing a low-cost, large area and solar blind detector technology for future use in hand-held devices with adapted system performance. Fraunhofer CAP is leading the project and contributing its many years of experience in the development of Raman LiDAR systems. The focus is on the reliable detection of gases from a distance as well as on the integration of all components into a practical complete system.

Added Value for Industry, Operators, and Technology Partners

For operators of energy and industrial facilities, the technology opens up new possibilities for the continuous monitoring of infrastructure, particularly in the context of a growing hydrogen economy. Thanks to the system’s enhanced molecular flexibility, different gases can be detected without the sensor technology needing to be pre-configured for specific substances. At the same time, the project aims to significantly reduce the size, complexity, and cost of the systems, thereby enabling compact, mobile, or permanently installed solutions for various application scenarios.

RADIANT also offers clear added value for industry and development partners. The detector and readout technologies developed in the project lay the foundation for application-oriented demonstrators that can eventually be transformed into marketable products. In this way, the Fraunhofer consortium supports companies in developing innovative safety and monitoring solutions and in tapping into new applications across the energy, process, and safety value chains.

RADIANT is funded by the Fraunhofer Joint Capability (JCAP) Building Program.