Main Research Methods
In photoacoustic (PA) signal generation, a gas sample is irradiated with a laser at an appropriate wavelength. The gas molecules that absorb the excitation light transition from their ground state to a higher energy state. When these excited molecules relax without radiation, they return to their ground state, releasing energy that heats the surrounding molecules.
If the excitation light is modulated periodically, the heat generation in the sample will also be periodic, creating a pressure fluctuation (sound wave) that can be detected with a microphone. The generated sound frequency matches the modulation frequency of the excitation, and its amplitude is proportional to the amount of absorbed light—ultimately revealing the concentration of the light-absorbing molecules.
By utilizing this effect, our research group develops gas analysis instruments to solve practical problems. Over the years, we have created several measurement devices that have been applied not only in scientific research but also in industrial settings. Currently, more than 100 industrial photoacoustic instruments for natural gas applications are produced annually in Szeged by Hobre Laser Technology Ltd., based on our research.
