Optimizing the Analytical Performance of Substrate-Integrated Hollow Waveguides: Experiment and Simulation.

Area of Science:

• Optical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Substrate-integrated hollow waveguides (iHWGs) are emerging optical components.
• Optimizing iHWG design is crucial for enhancing gas sensing performance.
• Previous studies have explored various iHWG configurations with limited comparative analysis.

Purpose of the Study:

• To experimentally and computationally compare eight substrate-integrated hollow waveguide (iHWG) designs.
• To identify key geometric and material factors influencing iHWG performance.
• To predict and propose novel iHWG structures for future development.

Main Methods:

• Experimental evaluation of isobutane calibration functions and analytical figures of merit (signal-to-noise ratio, limit of detection).
• Computational simulation of radiation incident at detectors for eight iHWG designs.
• Comparative analysis of experimental and simulation results to validate models.

Main Results:

• Excellent agreement between experimental and simulation results for radiation detection.
• iHWG geometry (inlet funnel and inner channel cross-section) significantly impacts light throughput.
• Inner channel material and surface polish showed minimal influence on performance.

Conclusions:

• iHWG geometry is the primary determinant of light throughput and analytical signal.
• Larger inlet funnel and inner channel dimensions enhance light throughput and signal.
• Simulations successfully predicted performance of novel iHWG designs, guiding future research.