Novel high contrast grating hollow core waveguides for enhanced gas spectroscopyAjmal Thottoli, Ganga Chinna Rao Devarapu, Antonella D’Orazio, Giovanni Magno and Liam O’FaolainEPJ Web Conf., 309 (2024) 01009DOI: https://doi.org/10.1051/epjconf/202430901009