Mid-infrared supercontinuum-based upconversion detection for trace gas sensing

Area of Science:

• Laser Spectroscopy
• Trace Gas Sensing
• Mid-Infrared (MIR) Technology

Background:

• Advancements in mid-infrared (MIR) supercontinuum light sources offer broad spectral coverage for laser-based trace gas sensing.
• Traditional MIR detection is limited by slow, expensive detector arrays, hindering high-speed broadband absorption signal measurement.

Purpose of the Study:

• To circumvent limitations of MIR detector arrays in broadband absorption spectroscopy.
• To enable fast and cost-effective trace gas detection using readily available near-infrared (NIR) detectors.

Main Methods:

• Demonstrated MIR-to-NIR signal upconversion to leverage silicon-based detector arrays.
• Integrated a MIR supercontinuum source, MIR-to-NIR upconverter, and an astigmatic multipass cell for gas detection.
• Employed a least-square global fitting method for multi-species detection analysis.

Main Results:

• Achieved fast detection (~20 ms) of ethane with sub-ppmv sensitivity at room temperature.
• Successfully utilized cost-effective NIR detector arrays for broadband absorption measurements.
• Demonstrated potential for multi-species gas detection.

Conclusions:

• The MIR-to-NIR upconversion technique overcomes detector limitations in MIR spectroscopy.
• This approach enables rapid, sensitive, and potentially low-cost trace gas sensing.
• The technology shows promise for environmental monitoring and biomedical research applications.