Wang, H., Ng, D. K. T., Wee, K. P. X., Xu, L., Chen, W., Anthony, A. A., Yap, J. V. W., Gu, Z., & Zhang, Q. X. (2026). Silicon photonic crystal emitter for multigas sensing. In L. P. Sadwick & T. Yang (Eds.), Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XIX (p. 16). SPIE. https://doi.org/10.1117/12.3080350
Abstract:
In this work, we present promising multi-gas sensing based on a silicon photonic crystal (PhC) emitter. A non-dispersive infrared (NDIR) sensor is developed to evaluate its sensing capability. First, the detection of carbon dioxide (CO2) and sulfur hexafluoride (SF6) are conducted. The gas response increases from 0.32 to 0.80 with the concentration of SF6 gas ranging from 10% to 99.99%. While for CO2, the gas sensor only shows a response change from 0.21 to 0.29 with concentration increasing from 10% to 99.8%. The high gas response of SF6 enables further development on SF6 ppm-level detection. Using an emitter array, a gas concentration of 50 ppm for SF6 can be detected by exploiting its absorption at 10.6 μm. To further expand the application of the emitter in various gas sensing, we characterize the signal response using a set of optical bandpass filters in a broadband from 3.33 μm to 10.6 μm. The measured response is high at different wavelengths, with 1.48 mV, 1.27 mV and 1.45 mV at 5.3 μm, 7.3 μm and 10.6 μm, respectively. Given the excellent performance of this gas sensor for SF6 gas at a wavelength of 10.6 μm, its detection of nitric oxide (NO) gas at a wavelength of 5.3 μm and sulfur dioxide (SO2) gas at a wavelength of 7.3 μm is also promising. Although the feasibility of testing different gases in the laboratory is currently limited, this gas sensor based on a broadband PhC emitter exhibits high flexibility, enabling the sensing of multiple gases in the same configuration.
License type:
Publisher Copyright
Funding Info:
This research / project is supported by the National Research Foundation - Low Carbon Energy Research (LCER) Phase 2
Grant Reference no. : U2303D4001
Description:
Copyright 2026 Society of Photo‑Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, and modification of the contents of the publication are prohibited.