Laser Absorption Spectroscopy - Precise Monitoring of Trace Gases
Keywords: Laser spectroscopy, trace gas analysis, intracavity spectroscopy
In intracavity absorption spectroscopy (ICLAS), the sample to be analyzed is placed directly inside the laser resonator (cavity), rather than passing the emitted laser beam externally through the sample. This approach increases sensitivity compared to conventional absorption measurements.
In the invention from TU Dortmund University, this sensitive spectroscopic measurement method is implemented in a two-mode configuration, greatly simplifying the evaluation of intracavity signals. The sample gas introduced into the laser resonator has an absorption line near one of the resonator modes. Due to mode competition, the absorption affects the relative strength of the two modes: if one is attenuated, the other is amplified. The energy transfer between the two resonator modes allows the gas to be detected and its concentration to be determined with high precision. Trace gases present in the air, such as methane or CO₂, can be detected very accurately in this way using a robust measurement setup. Reactive or environmentally harmful gases—which, among other things, contribute to the greenhouse effect—are also detected.
Advantages
- High detection sensitivity
- High spectral resolution of the absorption transitions, even for isotopic mixtures
- Compact and robust gas laser design possible
Commercial Applications
The improved intracavity absorption spectroscopy developed at TU Dortmund University enables the use of this measurement technique in trace gas analysis, industrial process monitoring, and security technology. It could be economically viable wherever particularly high detection sensitivity is required.
Current Status
The development of a prototype and implementation in the laboratory are planned. Corresponding grant applications have been submitted. An application has been filed with the German Patent and Trademark Office. Further nationalizations are possible within the priority year or via a subsequent PCT application. We offer interested companies the opportunity to license the technology and, in particular, to further develop it in collaboration with the inventors at TU Dortmund University.
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An invention of TU Dortmund University.