Optical Absorption of the Transition Elements in Vitreous Silica

The optical absorption of 3d transition elements in fused silica was studied. A series of high‐quality silica glasses doped with 0.01 to 0.1 wt% of each transition element (V through Cu) was prepared by a vapor hydrolysis technique. Their optical spectra were measured, and their practical absorptivities were calculated between 200 and 2000 nm. In the proposed waveguide use range (∼ 850 nm), V and Cr appear to absorb most (a pract = 2.6 and 1.2 dB/km ppbw −1 (metal), respectively) and Cu the least (a pract ≃0). Comparisons are made with data for conventional glasses.