Optimizing the Analytical Performance of Substrate-Integrated Hollow Waveguides: Experiment and Simulation. Issue 12 (December 2019)

• Record Type: Journal Article
• Authors: Hagemann, L. Tamina; Ehrle, Sonja; Mizaikoff, Boris
• Is Part Of: Applied spectroscopy. Volume 73:Issue 12(2019)
• Page Start: 1451
• Page End: 1460
• Publication Date: 2019-12
• Subjects: Substrate-integrated hollow waveguide -- iHWG -- Fourier transform infrared spectroscopy -- FT-IR -- infrared sensors -- mid-infrared -- MIR -- raytracing simulations -- FRED optical engineering software -- FRED; Spectrum analysis -- Periodicals; 543.505
• DOI: 10.1177/0003702819867342
• Languages: English
• ISSNs: 0003-7028

Abstract

The goal of this technical note was to compare experimentally and via simulation of eight substrate-integrated hollow waveguide (iHWG) designs, and to predict promising future iHWG structures in lieu of experiments. The iHWGs differed in their geometry (i.e., inlet funnel cross-section and inner channel cross-section), as well as in their material properties (i.e., type of metal, polish of inner channel). Experimentally, calibration functions of isobutane as a model analyte were determined, and the analytical figures of merit, i.e., signal-to-noise ratio, limit of detection, were evaluated for each iHWG. Evaluation of the amount of radiation incident at the real-world and simulated detector revealed that experiment and simulation were in excellent agreement. While material and quality of the inner channel wall did not have a significant influence on the performance, the iHWG geometry profoundly affected the performance in terms of light throughput: Increasing the inlet funnel dimensions and the inner channel cross-section benefits light throughout, and thus, the analytical signal. Based on these results, simulations of not yet fabricated iHWGs were performed and promising new iHWG structures were suggested.