Detection of atmospheric carbon dioxide with air-lasing-based coherent Raman spectroscopy

Area of Science:

• Spectroscopy
• Chemical Sensing
• Atmospheric Science

Background:

• Coherent anti-Stokes Raman scattering (CARS) is a powerful chemical sensing technique.
• Traditional CARS implementation is complex, limiting its use in atmospheric detection.
• Air lasing offers a simplified probe source for CARS, enhancing its applicability.

Purpose of the Study:

• To detect atmospheric carbon dioxide (CO2) using air-lasing-based CARS spectroscopy.
• To quantify CO2 concentration and assess the accuracy and precision of the developed method.
• To evaluate the potential of this technique for standoff detection of various substances.

Main Methods:

• Utilized air-lasing-based CARS spectroscopy for atmospheric CO2 detection.
• Quantified CO2 concentrations using two CARS signals.
• Compared results with a commercial gas analyzer to determine relative errors.

Main Results:

• Successfully detected atmospheric CO2 with concentrations of 485.5 ppm and 502.0 ppm.
• Achieved high accuracy with relative errors of 0.6% and 2.7% compared to a commercial analyzer.
• Established a detection limit of 43 ppm, an order of magnitude lower than previous methods.
• Demonstrated detection precision ranging from 9% to 10% for atmospheric CO2.

Conclusions:

• Air-lasing-based CARS spectroscopy enables simplified and effective atmospheric CO2 detection.
• The developed method offers high accuracy, improved detection limits, and reliable precision.
• This technique shows significant promise for standoff detection of air pollutants, biological agents, and radioactive substances.