Improved scintillating properties in Ce:YAG derived silica fiber with the reduction from Ce4+ to Ce3+ ions

The cerium (Ce)-doped optical fiber materials show great applications in smart lighting, fiber laser, and high-energy ray and particle detection. A major challenge is the efficient prevention of Ce3+ oxidized to Ce4+ ions. Here we report the CO2-laser-heated drawing method for fabricating Ce:YAG derived scintillating optical fiber with a concentration of Ce ions (0.21 wt%), and the effective atomic number is 25.4. The estimated ratio of Ce4+/Sigma Ce is 37% in the raw YAG ceramics, which can be effectively reduced to 3% in the fiber core because of the negative oxygen atmosphere during the fiber drawing process and the formation of non-bridging oxygen. The result is confirmed by the optical absorption spectrum, X-ray absorption fine structure spectra (XAFS), and Raman spectra. These induce a strong emission peak at 401 nm under the X-ray excitation. Moreover, the normalized integral scintillation efficiency of the Ce:YAG derived fiber is up to similar to 43% of that of Bi4Ge3O12 (BGO) scintillating crystal. The Ce:YAG derived optical fiber is believed to be a promising candidate for scintillators in remote fiber-optic radiation detection applications.