Influence of the monovalent bismuth on optical properties in Bi-doped silica optical fiber

Monovalent bismuth-related centers are studied by using first-principle methods in Bi-doped silica optical fiber. On the basis of 6-membered ring (6MR) model, the nBi-doped 6MR models are constructed for studying geo-metric and optical properties. With the quantity of monovalent bismuths increasing from one to three in 6MR model, the optical absorption intensity showed a trend of first increase and then decrease. The transition energy levels of monovalent bismuth-related model are studied with the time-dependent density functional theory (TDDFT). Our results showed that the( 3)P(1) -> P-3(0) transition of Bi (+) ion gives rise to near-infrared (NIR) luminescence around 1270 nm.