Luminescence and energy transfer characteristics in silica optical fiber materials with cerium and terbium co-doping

A cerium (Ce) and terbium (Tb) co-doped silica optical fiber (CTDF) is fabricated by the powder-in-tube technique. Its luminescence and energy transfer characteristics are investigated. The experimental results show that a strong excitation peak at 252 nm appears for the Tb-doped fiber materials. Another excitation peak with a similar intensity at 305 nm appears for the CTDF rod. The emission of Tb3+ ions at 542 nm is efficiently excited at 305 nm after Ce3+ ions doping in the silica fiber core. Moreover, the photoluminescence decay of CTDF rod materials at 542 nm is longer than that of Tb-doped fiber materials, from 1709.21 to 2173.17 μs. These results indicate that an obvious energy transfer process from Ce3+ to Tb3+ ions are achieved. Then, an energy level scheme with a local structure model of CTDF is built. Furthermore, numerical simulation results indicate that dipole-dipole interaction is the most-likely energy transfer mechanism. It is significant for the fabrication of Ce/Tb co-doped green emitting fiber lasers and remote fiber-optic radiation dosimeters.