Effect of dopants on transmission loss of low-OH-content optical fibres

Abstract
We formerly developed very-low-OH-content optical fibres consisting of a borosilicate cladding and a phosphosilicate core. The transmission loss of the fibre was 0.47 dB/km at 1.2 μm. We have further investigated the effects of dopants in pure silica on the losses of fibres. The letter clarifies the effects of dopants on the loss in the near-infrared region.