Wang, H., Tobing, L., Fu, Y.-H., Gu, Z., Khairy, M. H., Goh, J. S., & Zhang. (2025). Suspended honeycomb photonic crystal for high selective thermal emission at infrared wavelengths. In L. P. Sadwick & T. Yang (Eds.), Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XVIII (p. 9). SPIE. https://doi.org/10.1117/12.3043030
Abstract:
A middle infrared (MIR) light source with wavelengths matching specific gas absorption bands is needed for non-dispersive infrared (NDIR) chemical and gas sensing. To increase intensity at specific wavelength and thereby reduce the power consumption, a suspended MEMS emitter with photonic crystal (PhC) is designed and fabricated in this work. This emitter consists of a suspended phosphorus-doped silicon micro-hotplate perforated with a 2D honeycomb hole array. The membrane structure is compact in size, does not require substrate emission and reduces heat dissipation, which is conducive to the miniaturization of gas sensing. The absorptivity spectrum (i.e. the emissivity at thermal equilibrium) of PhC emitters is studied using Fourier transform infrared spectroscopy (FTIR), which is found to be in good agreement with our full wave simulations. Based on the FTIR results, a single emitter achieves selective enhancement of multiple wavelengths at 3.2 μm, 4.0 μm, and 6.0 μm, enabling real-time environmental monitoring of multiple gases. The PhC emitter power emission is up to 3.35 mW at 100 mA drive current, much higher than 1.88 mW of the slab emitter. Owing to a small emission area of 6720 μm2, a high-power intensity of 5.0 × 105 W/m2 is achieved, which is ideal for small foodprint use cases.
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Funding Info:
This research is supported by core funding from: Institute of Microelectronics, A*STAR (Agency for Science, Technology and Research)
Grant Reference no. :
This research / project is supported by the The National Research Foundation, Singapore, and Agency for Science, Technology and Research, Singapore - Low-Carbon Energy Research (LCER) Funding Initiative (FI)
Grant Reference no. : U2102d2012
This research / project is supported by the The National Research Foundation, Singapore, and Agency for Science, Technology and Research, Singapore - Low-Carbon Energy Research (LCER) Phase 2
Grant Reference no. : U2303D4001
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