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.