Segment-Resolved Gas Concentration Measurements by a Time Domain Multiplexed Dual Comb Method.

Area of Science:

• Spectroscopy
• Environmental Monitoring
• Optical Sensing

Background:

• Accurate gas concentration monitoring is crucial for environmental protection and industrial processes.
• Current methods often lack the spatial resolution needed for widespread detection.

Purpose of the Study:

• To develop a novel system for segment-resolved gas concentration measurement.
• To demonstrate the system's accuracy and potential for open-air applications.

Main Methods:

• Utilizing a time domain multiplexed dual-comb system.
• Separating interferograms in the time domain to derive absorption spectra and path lengths for multiple path-segments.
• Retrieving equivalent gas concentrations for each segment.

Main Results:

• Demonstrated a benchtop experiment with 1.08% relative deviation in gas concentration retrieval within 1 second.
• Numerical simulations showed minimal crosstalk (<0.1%) for kilometer-long atmospheric detection.
• Validated the ability to retrieve segment-specific gas concentrations.

Conclusions:

• The developed dual-comb system enables accurate, localized gas concentration measurements.
• This technology holds promise for gridded, regional gas concentration mapping in open environments.
• Potential applications include environmental atmospheric detection and emissions monitoring.