Flexible Scintillation Silica Fiber with Engineered Nanocrystals for Remote Real-Time X-ray Detection

Scintillation fibers based on rare-earth ion-doped crystal materials have attracted significant attention for applications in a wide range of areas from security to healthcare. However, the scintillation performance of crystal fibers is severely limited owing to the complex preparation process. Here, we report a modified preparation process of the transparent Ce/Tb co-doped yttrium pyrosilicate (YPS) nanocrystal silica fiber for the first time, which was fabricated by the CO₂ laser-heated method assisted with optimal thermal annealing. An YPS nanocrystal phase with an average size of approximately 38 nm is obtained by controlling the diffusion concentration of SiO₂ in the fiber core region. Both Ce³⁺ and Tb³⁺ ions were successfully embedded into YPS nanocrystals, which enhanced the energy transfer with an efficiency of 59.87% between the dopants as well as brighter green light emission. Furthermore, the X-ray-excited remote radioluminescence response of the obtained YPS nanocrystal fiber with a length of 20 m was approximately 1 order of magnitude larger than that of the precursor fiber, while the dose rate response exhibited excellent linearity. It is believed that the novel transparent YPS nanocrystal-doped silica optical fibers, combined with their excellent fluorescent properties, could be promising candidates for scintillators, fiber lasers, and phosphors.