Conquering the Rayleigh Scattering Limit of Silica Glass Fiber at Visible Wavelengths with a Hollow‐Core Fiber Approach

Abstract

Abstract The performance of optical fiber communication, laser, and sensing systems is ultimately limited by the attenuation of optical fiber, which cannot be lower than the barrier set by Rayleigh scattering in bulk silica glass. In this work, the longstanding Rayleigh scattering limit is conquered by using a hollow‐core fiber (HCF). Two visible‐guiding hollow‐core conjoined‐tube anti‐resonant fibers are successfully fabricated and exhibit overall losses of 3.8 dB km −1 at 680 nm and 4.9 dB km −1 at 558 nm, respectively. The latter surpasses the Rayleigh scattering limit of silica glass fiber by 2 dB km −1 at the corresponding wavelength. Numerical simulations indicate that the loss level the authors achieve is still much higher than the ultimate loss limit caused by surface scattering of this HCF geometry, leaving plenty of room for further refinement.