A team of researchers at the University of South Florida, led by Andreas Muller, has developed a groundbreaking portable Raman analyzer capable of accurately measuring very low concentrations of hydrogen gas in ambient air. The device addresses the critical need for detecting hydrogen leaks, which can pose significant safety risks due to the gas's flammability. The instrument's ability to sense small changes in hydrogen concentration from a distance is highlighted as a key feature for industrial applications where leaks may occur in pipelines or storage tanks. Published in Applied Optics, the study demonstrates the analyzer's effectiveness in detecting hydrogen levels well below 1 part per million in the air, enabling the identification of leaks several meters away. The researchers leveraged Raman scattering, a technique using light to identify and measure substances, to develop the portable gas analyzer. By incorporating multipass cavity enhancement, the device can enhance the Raman scattering signal, facilitating the detection of low gas concentrations. This innovation overcomes limitations of current portable hydrogen sensors, which often rely on indirect methods and struggle to measure very low concentrations accurately. To ensure the instrument's adaptability to various environments, the team utilized a laser with high output power and a narrow linewidth, along with a stable multipass cavity that remained unaffected by temperature changes. Graduate student Charuka Arachchige led the evaluation of the analyzer's stability and sensitivity in different locations, showcasing consistent hydrogen concentration variations influenced by environmental factors. The findings from the study indicate the analyzer's ability to detect hydrogen leaks from significant distances, even outdoors. The researchers are committed to further enhancing the instrument's capabilities in terms of detection limits, recording speed, and portability, with potential applications in industrial safety, scientific research, and medical settings. The innovative portable Raman analyzer holds promise for improving safety measures and minimizing risks associated with hydrogen gas leaks.