RARE EARTH-DOPED CORE OPTICAL FIBER AND METHOD FOR MANUFACTURE THEREOF

摘要

Disclosed is a rare earth-doped core optical fiber, which comprises: a core which comprises a silica glass containing at least aluminum and a rare earth element; and a clad which is provided around the core and comprises a silica glass having a lower refraction index than that of the core, wherein the core has an aluminum content of 2% by mass or more, and ytterbium is doped into the core in such an amount that a light absorption spectrum of ytterbium doped in the core which appears around a wavelength of 976 nm shows a peak light absorption rate of 800 dB/m or less.