Hydrogen gas is hailed as a promising energy source due to its lightweight, storable, and environmentally friendly characteristics compared to fossil fuels. However, its high flammability necessitates reliable leak detection methods. One such method, tunable diode laser absorption spectroscopy (TDLAS), has emerged as a promising technology for gas detection. While effective, detecting low concentrations of hydrogen with TDLAS presented challenges due to hydrogen's weak absorption in the infrared region. To overcome this, a research team from Japan, led by Associate Professor Tatsuo Shiina, developed an innovative method for precise hydrogen gas measurement using TDLAS. The team meticulously controlled pressure and modulation parameters in the TDLAS setup to achieve highly sensitive detection of hydrogen gas. By introducing a calibration-free technique and optimizing modulation parameters based on the width of hydrogen's absorption line at different pressures, the researchers successfully detected hydrogen concentrations from 0.01% to 100%, with a minimum detection limit as low as 55 parts per million (ppm) at 30 seconds integration time. The system's potential applications include enhancing safety and quality control in hydrogen detection systems, such as leak detection in hydrogen fuel cell cars. Associate Professor Tatsuo Shiina's pioneering technique could contribute to a sustainable future by promoting the wider adoption of hydrogen as an eco-friendly fuel. His extensive research background and membership in various academic societies further underscore his expertise in the field of photoelectric measurement and scattering optics.