We study the influence of alkali oxides on the near-infrared (NIR)-emitting thermal stability of Bi-doped R2O–SiO2–B2O3–Al2O3 (R = Li, Na, K) glasses below Tg. Results show that undergoing heat treatment, re-markable luminescence quenching occurs for the glasses containing Na2O and K2O due to the formation of Bi metallic colloids, whereas the glass with Li2O shows much better thermal stability. These changes can be understood by the tendency of modifier cations with lower mobility and higher tightness network to restrain the transport of Bi-related NIR-emitting centers. The results provide a scientific reference for composition design of Bi-doped optical fiber.

The influence of silver nanoparticles on Er3+ up-conversion in CaF2 precipitated oxyfluoride glass-ceramics is investigated. After heat-treatments, transmission electron microscopy images show that CaF2 nanocrystals precipitate in the glass matrix uniformity, and sliver nanoparticles are spread around the CaF2 nano-crystals simultaneously. Comparing with the samples without Ag doped, high efficiency up-conversion luminescences of Er3+ at 540 and 658 nm are distinctly observed in the silver nanoparticles containing glass-ceramics by the 980-nm excitation. Moreover, since the intensity ratio of green and red emissions changes after silver nanoparticles precipitation, the up-conversion mechanism of Er3+ is discussed.

Three-dimensional-ordered Yb/Er co-doped Bi2Ti2O7 inverse opal, powder, and disordered reference samples are prepared and their upconversion (UC) emission properties and mechanisms are investigated. Significant suppression of UC emission is detected when the photonic band-gaps overlap with Er3+ UC green emission bands. Interestingly, green and red UC emissions follow a two-photon process in the powder sample but a three-photon one in the inverse opal.

新型光纤数字化电子式电流互感器(ECT)是在普通ECT的基础上改进其存在的一些不足, 使之精度更高, 功耗更低, 功能更完善, 适用于数字化变电站的要求。文章首先介绍了新型光纤数字化ECT的总体设计, 然后分别介绍了组成新型数字化ECT的高压侧数据采集器和低压侧合并单元(MU), 最后介绍了新型数字化ECT的供能方案。