Hollow-Core Fiber for Single-Mode, Low Loss Transmission of Broadband UV Light

We report on an anti-resonant hollow-core fiber (AR-HCF) designed for stable transmission of laser light in a broad wavelength range of 250 nm to 450 nm. We tested for wavelengths of 300 nm and 320 nm. The characterized fiber shows a low transmission power attenuation of 0.13 dB/m and an excellent single-mode profile. The fiber maintains stable transmission after an exposure of tens of hours with up to 60 mW CW-laser light and shows no indication of solarization effects. We further tested its performance under bending and observed a small critical bending radius of about 6 cm. These characteristics make the presented fiber a useful tool for many applications, especially in quantum optics labs where it may be instrumental to improve on stability and compactness.