Mid-IR absorption spectroscopy is a critical tool for chemical sensing and analysis especially for inert gases that evade detection by chemical reaction-based sensors mid-IR photonic integrated circu

Infrared (IR) absorption spectroscopy is a crucial technique for chemical sensing and analysis, particularly for inert gases that are not detectable using chemical reaction-based sensors. The development of mid-IR photonic integrated circuit (PIC) platforms has enabled the miniaturization of optical gas sensors to the size of a chip. In recent years, research has focused on the utilization of mid-IR PIC sensing platforms and waveguide-integrated mid-IR light sources and detectors based on semiconductors such as PbTe, black phosphorus, and tellurene. However, the operation of these platforms is limited to wavelengths λ ≲ 4 μm due to the bandgap of the materials used and the reliance on SiO2 substrates