1-km Hollow-Core Fiber With Loss at the Silica Rayleigh Limit in the Green Spectral Region

In this letter, we report on the fabrication of an inhibited-coupling guiding fiber with a cladding amorphous lattice of nine tubes exhibiting a record loss of 13.8 dB/km at 539 nm. The fiber has been drawn over a length of 1 km with high stability during the drawing process (outer diameter variation of ±0.2%). To our knowledge, this is the first time that loss figures and the fundamental Rayleigh scattering limit of silica are reported for a hollow-core optical fiber in the green spectral range. Also, this is the first report on a tubular fiber draw over such a long length. Additionally, this record loss figure is the lowest ever demonstrated with any kind of optical fibers in the green spectral range.