Step index multimode high attenuation fibers made from reconstructed glasses

High attenuation fibers (HAF) are used in telecommunications networks to attenuate signals or to eliminate end-of-line reflections. In the latter case, one usually refers to terminators. These types of fibers contain dopants in their cores, usually transition metal oxides, which absorb the light travelling in the fibers. Single mode HAF are made by the modified chemical vapor deposition (MCVD) process, and the solution doping technique, which is used to incorporate the transition elements.