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High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
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Flow-Enhanced Photothermal Spectroscopy
Ulrich Radeschnig1, Alexander Bergmann1, Benjamin Lang1
1Institute of Electrical Measurement and Sensor Systems, Graz University of Technology, 8010 Graz, Austria.
Sensors (Basel, Switzerland)
|October 14, 2022
Summary
Signal intensity in photothermal spectroscopy (PTS) using a Fabry-Pérot interferometer (FPI) depends on excitation modulation frequency and gas flow velocity. We identified an optimal working regime for improved gas sensing performance.
Area of Science:
- Gas sensing
- Spectroscopy
- Optical instrumentation
Background:
- Photothermal spectroscopy (PTS) is a key technique for gas and aerosol measurement.
- Fabry-Pérot interferometer (FPI)-based PTS systems offer robustness and miniaturization potential.
- Optimizing PTS signal intensity requires understanding parameter interactions.
Purpose of the Study:
- To investigate the influence of excitation modulation frequency and gas flow velocity on FPI-based PTS signal intensity.
- To develop an analytical model for predicting PTS signal intensity based on these parameters.
- To identify an optimal working regime for enhanced gas sensing.
Main Methods:
- Utilized a collinear excitation laser configuration in an FPI-based PTS setup.
- Systematically varied excitation modulation frequency and gas flow velocity.
- Developed and experimentally validated an analytical model correlating signal intensity with parameter settings.
Main Results:
- Demonstrated significant impact of the ratio between modulation frequency and gas flow velocity on thermal wave generation and signal intensity.
- The analytical model accurately predicted experimental signal intensities.
- Identified a specific optimal working regime for the FPI-based PTS system.
Conclusions:
- The interplay between modulation frequency and gas flow velocity is critical for optimizing FPI-based PTS performance.
- The developed model provides a valuable tool for tuning PTS systems for improved gas sensing.
- This study elucidates a key operational parameter for enhancing FPI-based photothermal spectroscopy.
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