Single-mode optical fiber for high-power, low-loss UV transmission
  We report large-mode-area solid-core photonic crystal fibers made from fused silica that resist ultraviolet (UV) solarization even at relatively high optical powers. Using a process of hydrogen loading and UV irradiation of the fibers, we demonstrate stable single-mode transmission over hundreds of hours for fiber output powers of 10 mW at 280 nm and 125 mW at 313 nm (limited only by the available laser power). Fiber attenuation ranges from 0.9 dB/m to 0.13 dB/m at these wavelengths, and is unaffected by bending for radii above 50 mm. 
Yves Colombe, Daniel H. Slichter, Andrew C. Wilson, Dietrich Leibfried   and David J. Wineland
quant-ph physics.optics