Ultrashort pulses at 920 nm are a highly desired light source in two-photon microscopy for the efficient excitation of green fluorescence protein. Although Nd^{3 +} -doped fibers have been utilized for 920-nm ultrashort pulse generation, the competitive amplified spontaneous emission (ASE) at 1.06 μm remains a significant challenge in improving their performance. Here, we demonstrate a coordination engineering strategy to tailor the properties of Nd^{3 +} -doped silica glass and fiber. By elevating the covalency between Nd^{3 +} and bonded anions via sulfur incorporation, the fiber gain performance at 920 nm is enhanced, and 1.06-μm ASE intensity is suppressed simultaneously. As a result, the continuous-wave laser efficiencies and signal-to-noise ratio at 920 nm by this fiber are significantly enhanced. Importantly, the stable picosecond pulses at 920 nm are produced by a passive mode-locking technique with a fundamental repetition rate up to 207 MHz, which, to the best of our knowledge, is the highest reported repetition rate realized by Nd^{3 +} -doped silica fibers. The presented strategy enriches the capacity of Nd^{3 +} -doped silica fiber in generating 920-nm ultrashort pulses for application in biophotonics, and it also provides a promising way to tune the properties of rare-earth ion-doped silica glasses and fibers toward ultrafast lasers.

Lead halide perovskite materials exhibit excellent scintillation performance, which, however, suffer from serious stability and toxicity problems. In contrast, the heavy metal-free anti-perovskite materials [ MX₄ ] XA₃ (A = alkali metal; M = transition metal; X = Cl, Br, I), a class of electron-inverted perovskite derivatives, exhibit robust structural and photophysical stability. Here, we design and prepare a lead-free [ MnBr₄ ] BrCs₃ anti-perovskite nanocrystal (NC)-embedded glass for efficient X-ray-excited luminescence with high-resolution X-ray imaging with a spatial resolution of 19.1 lp mm ^{- 1}. Due to the unique crystal structure and the protection of the glass matrix, the Cs₃MnBr₅ NC-embedded glass exhibits excellent X-ray irradiation stability, thermal stability, and water resistance. These merits enable the demonstration of real-time and durable X-ray radiography based on the developed glassy composite. This work could stimulate the research and development of novel metal halide anti-perovskite materials and open a new path for future development in the field of high-resolution and ultrastable X-ray imaging.

自诺贝尔奖获得者高锟提出可用玻璃光纤代替传统电缆传输线，利用光波导传输光信号的方法来实现信息传输以来，人们就一直致力于优化现有光纤的性能和探索新的光纤激光介质材料。目前，用于光通信系统的光纤激光器和光放大器的增益光纤多见于稀土离子掺杂玻璃光纤，然而稀土离子固有的f-f跃迁导致较窄的传输带宽已经无法满足日益剧增的网络数据传输需求。铋（Bi）离子是继过渡金属离子、稀土离子后的第三类激活离子, 是激光材料领域发展的新方向。目前，Bi掺杂玻璃光纤已经在1150~1550 nm和1600~1800 nm范围内实现了激光输出和光信号放大。这充分说明了Bi掺杂玻璃光纤有望解决现有数据传输能力不足的问题，成为新一代光纤激光器和放大器的增益材料。因此，文中主要介绍Bi掺杂玻璃和光纤的研究进展，分析Bi掺杂玻璃及光纤材料目前存在的问题，并展望了未来的研究方向。

近年来，全无机钙钛矿量子点因其优异的光电性能受到研究者的广泛关注，但其较差的稳定性极大地限制了其应用。利用玻璃优异的稳定性，控制钙钛矿量子点在玻璃中原位析出，使玻璃包覆在钙钛矿量子点周围，隔绝其与外界环境的接触，有效地提高了其稳定性。通过在钙钛矿量子点玻璃中掺杂特定的离子可以调控钙钛矿量子点的析晶情况和发光峰位，并可引入新的发光中心。本文根据掺杂离子的目的，综合介绍了离子掺杂钙钛矿量子点玻璃的研究进展，为近期关于离子掺杂钙钛矿量子点玻璃的研究提供了思路和参考。

With the rapid growth of optical communications traffic, the demand for broadband optical amplifiers continues to increase. It is necessary to develop a gain medium that covers more optical communication bands. We precipitated PbS quantum dots (QDs) and BaF2:Tm3+ nanocrystals (NCs) in the same glass to form two independent emission centers. The BaF2 NCs in the glass can provide a crystal field environment with low phonon energy for rare earth (RE) ions and prevent the energy transfer between RE ions and PbS QDs. By adjusting the heat treatment schedule, the emission of the two luminescence centers from PbS QDs and Tm3+ ions perfectly splices and covers the ultra-broadband near-infrared emission from 1200 nm to 2000 nm with bandwidth over 430 nm. Therefore, it is expected to be a promising broadband gain medium for fiber amplifiers.