高效的光调制能够显著提高光转换效率和调节光响应速率，在光电子学领域中表现出巨大的应用潜力。然而，光子之间的弱相互作用对操纵光子-光子相互作用造成了巨大的障碍。本文采用850 nm和1 550 nm激光同时激发含有Er³⁺∶NaYF₄纳米晶体的氧氟化物微晶玻璃，可以实现绿色上转换荧光的快-慢光调制。与两束单波长激发的发光强度之和相比，双波长同时激发的绿色上转换发光强度明显提高了一个数量级。值得注意的是，绿色上转换发光快-慢响应速率依赖于双波长激发的泵浦策略，显示出高达4倍的快-慢响应差异。研究表明，双波长激发绿色上转换发光的快-慢光调制在新型的全光开关中具有广阔的应用前景。

光催化被广泛用于去除水中的难降解有机污染物, 但是由于光生电子和空穴的复合率高, 抑制了半导体光催化剂的催化活性。本研究通过简便的溶剂热法成功制备了一种BiOBr/ZnMoO₄复合材料。通过结构分析、原位XPS、功函数测试、自由基捕获及电子顺磁共振(ESR)实验等证实了BiOBr/ZnMoO₄复合材料形成了S型异质结。实验结果表明, 适当ZnMoO₄含量的BiOBr/ZnMoO₄异质结可以显著提高BiOBr的光催化性能。与纯BiOBr、ZnMoO₄相比, 质量分数15% BiOBr/ZnMoO₄在可见光下表现出最佳的光催化活性, 双酚A的光催化降解率达到85.3% (90 min), 环丙沙星的光降解速率常数分别是BiOBr的2.6倍和ZnMoO₄的484倍。这可归因于BiOBr和ZnMoO₄之间形成了紧密的界面结合和S型异质结, 使得光生载流子可以实现有效的空间分离和转移。这项工作为定向合成Bi基S型异质结复合光催化材料提供了一种简便有效的方法, 对进一步理解Bi基多元异质结光催化材料的构效关系提供了新的理论和实验基础。

Bismuth (Bi)-doped near-infared (NIR) glass that can cover the entire optical communication window (850, 1310, and 1550 nm) has become the subject of extensive research for developing photonic devices, particularly, tunable fiber lasers and ultrabroadband optical amplifiers. However, the realization of highly efficient NIR luminescence from Bi-doped glass is still full of challenges. Notably, due to the co-existence of multiple Bi NIR centers in the glass, the origin of newly generated Bi NIR emission peaks at ∼930 and ∼1520 nm is still controversial. Here, we report a new Bi-doped nitridated germanate glass with tunable ultrabroadband NIR emission (850–1700 nm) and high external quantum efficiency (EQE) of ∼50%. A series of studies, including spectral analysis, nuclear magnetic resonance (NMR), and others, provide powerful evidence for the mechanism of luminescence enhancement and tunability, and make reasonable inferences about the origin of the new emission bands at ∼930 and ∼1520 nm. We believe that the results discussed above would enrich our understanding about multiple Bi NIR emission behaviors and contribute to the design and fabrication of highly efficient Bi-doped ultrabroadband wavelength-tunable optical glass fiber amplifiers and lasers in the future.

We report on a conceptually new type of waveguide in glass by femtosecond laser direct writing, namely, photonic lattice-like waveguide (PLLW). The PLLW’s core consists of well-distributed and densified tracks with a sub-micron size of 0.62 µm in width. Specifically, a PLLW inscribed as hexagonal-shape input with a ring-shape output side was implemented to converse Gaussian mode to doughnut-like mode, and high conversion efficiency was obtained with a low insertion loss of 1.65 dB at 976 nm. This work provides a new freedom for design and fabrication of the refractive index profile of waveguides with sub-micron resolution and broadens the functionalities and application scenarios of femtosecond laser direct-writing waveguides in future 3D integrated photonic systems.