Fiber-Coupled Substrate-Integrated Hollow Waveguides: An Innovative Approach to Mid-infrared Remote Gas Sensors

Area of Science:

• Optics and Photonics
• Spectroscopy
• Environmental Sensing

Background:

• Mid-infrared (MIR) spectroscopy is crucial for gas analysis.
• Miniaturized gas cells are needed for remote and low-volume sensing.
• Fiber-optic integration offers remote addressing capabilities.

Purpose of the Study:

• To demonstrate fiber-coupled substrate-integrated hollow waveguide (iHWG) gas cells for remote MIR sensing.
• To assess the feasibility of analyzing low sample volumes for hydrocarbon detection.
• To investigate the sensitivity and reproducibility of the fiber-iHWG interface.

Main Methods:

• Development and characterization of fiber-optically coupled iHWG gas cells.
• Configuration of iHWGs in a double-pass geometry for enhanced light interaction.
• Coupling iHWGs to a mid-infrared fiber bundle and Fourier transform infrared spectrometer.
• Analysis of gaseous hydrocarbons and evaluation of interface assembly reproducibility.

Main Results:

• Successful demonstration of remotely addressable iHWG gas cells via fiber optics.
• Feasibility of low-level hydrocarbon gas analysis using the developed system.
• Broadband MIR sensing achieved with fiber-coupled iHWGs.
• Investigation into sensitivity and reproducibility of the fiber-iHWG interface.

Conclusions:

• Fiber-optically coupled iHWGs are a viable approach for remote MIR gas sensing.
• The system enables sensitive detection of hydrocarbons in low sample volumes.
• This technology holds promise for remote environmental monitoring and analysis.