Novel high contrast grating hollow core waveguides for enhanced gas spectroscopy

The article presents an innovative approach to confining waves in planar high contrast grating hollow core waveguides, design achieves a surface that reflects waves effectively while maintaining a structure that allows for high transmission. The unique side-open waveguide system also allows for gas flow through the sidewalls, making it suitable for gas spectroscopic techniques. The HCW design is specifically tailored for methane gas sensing at a wavelength of 3.27 μm. Numerical analysis shows that the transmittance can reach up to -0.41 dB. These findings demonstrate the potential of high-transmitting hollow-core waveguides for gas sensing, highlighting the effectiveness and cost-efficiency of chip-scale photonic integration.