Near-IR luminescence characteristics of monovalent bismuth in Bi-doped pure silica optical fiber: First-principle study

Monovalent bismuth-related centers in pure silica optical fiber are calculated by using first-principle methods. Transition energy levels of three different structural models are investigated on the basis of the time-dependent density functional theory (TDDFT). Compared with the experimental data of near-IR luminescence, our calculated results suggested that luminescence near 1492 nm is likely caused by SiOBi configuration; and luminescence at 1147 nm and 1403 nm may be caused by interstitial Bi₂O molecule. Moreover, SiBi configuration, which might be the origin of the luminescence near 1629 nm, is difficult to directly form because of its relatively high formation energy.