Ultra-thin-membrane nodeless single-ring anti-resonant hollow-core fibers

Nodeless anti-resonant hollow-core fibers (AR-HCFs) have emerged as a promising platform for light-gas interactions. In this work, we demonstrate a post-processing tapering technique for fabricating single-ring ARFs (SR-ARFs) with ultra-thin cladding membranes. By precisely controlling the gas pressure applied to both the core and cladding regions during tapering, we reduced the glass wall thickness to a record-low value of ∼60 nm-representing, to the best of our knowledge, the thinnest walls ever achieved in uniform SR-ARFs longer than 10 cm. The fabricated fibers were comprehensively characterized through spectral transmission measurements, high-resolution scanning electron microscopy combined with volume-conservation analysis, and non-destructive side-scattering spectroscopy. Beyond wall thinning, we further employed a gas inflation technique to enlarge the fiber core diameter, achieving a maximum expansion of over two times the original size and a core diameter of 70.5 µm. These results highlight the versatility of post-processing in tailoring AR-HCF geometries, opening new opportunities for advanced photonic applications, particularly in the ultraviolet regime.