Enhanced radiation resistance of Er3+/Yb3+ co-doped high-phosphorus silica glasses and fibers via phase-interface engineering

Abstract

High-energy irradiation significantly increases the optical losses and noise coefficients of laser materials, leading to a substantial decrease in the slope efficiency or gain performance of laser output. To address this issue, we propose a strategy to enhance the radiation resistance of glasses/fibers by introducing phase interfaces. Based on the sol–gel method, through phase-separation techniques and high-temperature annealing treatments, silica-rich and phosphorus-rich phases were formed in erbium-ytterbium co-doped high-phosphorus silica glass, and nanoscale phase interfaces with specific densities, stability levels, and homogeneous distributions of doped elements were constructed between the phases. Using high-resolution transmission electron microscopy, nuclear magnetic resonance, and spectroscopic analyses, we tracked the evolution of the internal microstructure of the glasses at the atomic level. The findings confirmed that annealing effectively controlled the density of the phase interfaces formed. Under 1 kGy X-ray irradiation, glasses with effective phase interfaces exhibited significant reduction in radiation-induced attenuation (RIA) and improvement in photoluminescence intensity compared to pristine glasses. This indicated that effective phase interfaces could act as complex centers for irradiation-induced point defects, absorbing radiant energy and trapping these defects, thus mitigating high-energy radiation-induced damages. Furthermore, online irradiation tests on the Er³⁺/Yb³⁺ co-doped silica fibers supported this result. Compared to pristine fiber, fibers annealed for 3 h and annealed for 20 h with different phase interfacial densities showed 45% and 73% lower RIA at 1080 nm, respectively.

Graphical Abstract

Erbium-ytterbium co-doped high-phosphorus silica glasses/fibers with nanoscale phase interfaces were prepared using a modified sol–gel method. The density of the phase interfaces increased with annealing, which significantly improved their radiation resistance. Online irradiation showed that the radiation-induced attenuation at 1080 nm reduced by 73% compared with that of pristine fibers.