Hugo Geiger Prize 2025

This year’s Hugo Geiger Prize for the best doctoral theses in applied research goes to three early-career researchers from Jena and Freiburg. Jointly awarded by the Bavarian State Ministry of Economic Affairs, Regional Development and Energy (StMWi) and the Fraunhofer-Gesellschaft, the prize recognizes innovative solutions developed by doctoral researchers in close cooperation with a Fraunhofer institute.

Synchronizing quantum communication

Whether in 5G networks, industrial automation or smart power grids − modern interconnected systems can only function if they are synchronized with precise timing. In quantum communication, this precision is particularly critical: Even the slightest deviations caused by turbulence, vibrations or temperature fluctuations can disrupt the secure exchange of information. Christopher Spiess from the Fraunhofer Institute for Applied Optics and Precision Engineering IOF has developed a new synchronization method. Rather than relying on additional synchronization lasers or expensive atomic clocks, this uses the photons already transmitted during quantum communication as highly precise timing references. The system analyzes the arrival times of the photons, compensating for disruptions in real time using specialized algorithms. This creates a stable common timing signal with picosecond accuracy, making free-space links significantly more robust. Tests conducted over a 1.7-kilometer free-space link and a 70-kilometer fiber-optic connection demonstrate that quantum links can be reliably stabilized. The findings from Spiess’s doctoral research have already been incorporated into numerous national and European projects and also industrial applications. Beyond quantum communication, the method opens up new possibilities for telecommunications, satellite communications and precision measurement, and it is considered a key technology for future quantum infrastructures.

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Innovative trace-gas sensors using the photoacoustic effect

Elevated concentrations of carbon dioxide and nitrogen dioxide can impair well-being and harm our health − often without us noticing. At the Fraunhofer Institute for Physical Measurement Techniques IPM in Freiburg, Christian Weber has developed a method for large-scale, cost-effective and reliable monitoring of such trace gases. Based on a long-established measurement principle, his approach lays the foundation for a new generation of compact, energy-efficient gas sensors capable of reliably detecting CO₂ and NO₂ even at very low concentrations − and at a fraction of the cost of existing technologies. This is made possible by the photoacoustic effect: Light generates sound, and the intensity of that sound provides precise information about the gas concentration. Weber has developed both a compact, energy-efficient and low-maintenance CO₂ sensor for applications such as indoor air monitoring and a novel NO₂ sensor that achieves particularly low detection limits thanks to a patented method, while remaining robust under external influences. Whether in indoor spaces, tunnels or underground parking garages, as well as in the monitoring of anesthetic gases in medical settings or in detecting methane or refrigerant leaks: These sensors perform particularly well in situations where large, expensive and energy-intensive measurement devices reach their limits. This innovation has already been incorporated into more than ten industrial projects.

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Detecting bacteria and resistance more quickly

Antibiotic resistance is one of the greatest challenges facing our healthcare system, yet it is often detected too late. Anne-Sophie Munser from the Fraunhofer Institute for Applied Optics and Precision Engineering IOF has taken a measurement method from photonics and applied it to cell biology. This approach makes it possible to identify harmful bacteria and determine the effectiveness of antibiotics significantly faster than would be possible using existing methods. With the help of angle-resolved scattered-light analysis, she is able to detect even very small numbers of microbial cells without the need for time-consuming cultivation. The technology can detect individual cells in a fraction of a second, allowing bacteria and their resistance patterns to be identified within around three hours − much faster than conventional diagnostic methods, which often take hours or even days. The principle behind the method is that scattered light correlates closely with the structural properties of the illuminated object. This produces a characteristic light distribution that reveals surface roughness and cellular structures down to the nanometer scale, allowing conclusions to be drawn about the type of microorganism and its aggregation behavior. Through her work, Munser is laying the foundations for compact high-throughput systems − including potential lab-on-a-chip solutions − that are capable of analyzing thousands of samples in a very short space of time. As such she is making a vital contribution to combating antibiotic-resistant pathogens. The method can be used not just for faster and more precise diagnostics in medicine and infection biology but also for monitoring food and drinking water.

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On March 26, 1949, the Fraunhofer-Gesellschaft was founded at the Bavarian Ministry of Economic Affairs under the patronage of State Secretary Hugo Geiger. On the occasion of Fraunhofer’s 50th anniversary, the Bavarian Ministry of Economic Affairs, Regional Development and Energy launched the Hugo Geiger Prize for the next generation of research scientists. Awarded each year to three researchers, the prize honors outstanding doctoral theses in the field of applied research that have been completed in collaboration with a Fraunhofer institute. The individual prizes amount to 5,000, 3,000 and 2,000 euros. The submissions are assessed by an expert panel of judges made up of representatives from the worlds of research and industry. The assessment criteria are scientific quality, relevance to industry, originality and use of interdisciplinary methods.