Abstract

Photosensitivity in optical fibers^[1], where exposure to short wavelength light creates a permanent refractive index change, has been reported to date only in fiber containing germanium in the core. In this paper we report the first observation of UV and visible light photosensitivity-in Ge-free Eu²⁺:Al₂O₃-doped-core fiber. The fiber, core diameter 11.5 μm, cladding diameter 124.8 μm and N. A 0.08, was fabricated using MCVD and the Brown University aerosol dopant delivery method^[2]. Spectroscopic measurements o n t he preform (spatially resolved) revealed absorption peaks at 577, 531 and 464 nm, which we attribute to traces of Eu³⁺ in the outer shell of the core, and a very strong peak at 260 nm due to the Eu²⁺ core dopant.

© 1991 Optical Society of America