An optical micro/nanofiber (MNF) is a quasi-one-dimensional free-standing optical waveguide with a diameter close to or less than the vacuum wavelength of light. Combining the tiny geometry with high-refractive-index contrast between the core and the surrounding, the MNF exhibits favorable optical properties such as tight optical confinement, strong evanescent field, and large-diameter-dependent waveguide dispersion. Meanwhile, as a quasi-one-dimensional structure with extraordinarily high geometric and structural uniformity, the MNF also has low optical loss and high mechanical strength, making it favorable for manipulating light on the micro/nanoscale with high flexibility. Over the past two decades, optical MNFs, typically being operated in single mode, have been emerging as a miniaturized fiber-optic platform for both scientific research and technological applications. In this paper, we aim to provide a comprehensive overview of the representative advances in optical MNFs in recent years. Starting from the basic structures and fabrication techniques of the optical MNFs, we highlight linear and nonlinear optical and mechanical properties of the MNFs. Then, we introduce typical applications of optical MNFs from near-field optics, passive optical components, optical sensors, and optomechanics to fiber lasers and atom optics. Finally, we give a brief summary of the current status of MNF optics and technology, and provide an outlook into future challenges and opportunities.

An optical field with sub-nm confinement is essential for exploring atomic- or molecular-level light-matter interaction. While such fields demonstrated so far have typically point-like cross-sections, an optical field having a higher-dimensional cross-section may offer higher flexibility and/or efficiency in applications. Here, we propose generating a nanoscale blade-like optical field in a coupled nanofiber pair (CNP) with a 1-nm-width central slit. Based on a strong mode coupling-enabled slit waveguide mode, a sub-nm-thickness blade-like optical field can be generated with a cross-section down to ∼0.28nm×38nm at 1550 nm wavelength (i.e., a thickness of ∼λ0/5000) and a peak-to-background intensity ratio (PBR) higher than 20 dB. The slit waveguide mode of the CNP can be launched from one of the two nanofibers that are connected to a standard optical fiber via an adiabatical fiber taper, in which a fundamental waveguide mode of the fiber can be converted into a high-purity slit mode with high efficiency (>98%) within a CNP length of less than 10 μm at 1550 nm wavelength. The wavelength-dependent behaviors and group velocity dispersion in mode converting processes are also investigated, showing that such a CNP-based design is also suitable for broadband and ultrafast pulsed operation. Our results may open up new opportunities for studying light-matter interaction down to the sub-nm scale, as well as for exploring ultra-high-resolution optical technology ranging from super-resolution nanoscopy to chemical bond manipulation.

从光学工程应用的角度对全国云量情况进行了研究，重点分析了全国陆地主要地区云量总体平均情况、冷暖半年、昼夜变化等三个方面云量历史数据，研究结果表明：全国陆地主要地区总云量和低云量分布区域基本呈北少南多的情况；冷暖半年云量分布有较明显的差别，暖半年云量高于冷半年的站点区域占全国较大面积；昼夜云量分布区别主要体现在西部地区白天低云低值区会有中高云存在。在云量总体平均情况、冷暖半年、昼夜变化的分析基础上进而讨论了全国云量区域的分级情况，结果表明适合光学工程应用的1级区主要分在北方。结果有助于了解全国适于开展光学工程应用的区域，并可为进一步研究云量对光学工程应用产生的定量影响提供参考。

为研究透射式GaAs光电阴极在不同波长入射光环境下的图像分辨能力，提出了一种基于散射传递函数的AlGaAs窗口层界面散射理论模型。制作了透射式GaAs光电阴极，利用不同波长入射光散射传递函数和点扩散函数变化，基于有参峰信噪比拟合对AlGaAs窗口层界面散射引起的入射光学图像退化程度进行了定量分析。结果表明，在相同的粗糙度下随着入射光波长的增加，入射光学图像的能量损失越小，成像质量越高，而三代微光像增强器不同波长入射光测试条件下极限分辨力变化趋势与仿真计算结果一致，可为后续提高透射式GaAs光电阴极分辨力提供了技术支撑。

We propose to generate a sub-nanometer-confined optical field in a nanoslit waveguiding mode in a coupled nanowire pair (CNP). We show that, when a conventional waveguide mode with a proper polarization is evanescently coupled into a properly designed CNP with a central nanoslit, it can be efficiently channeled into a high-purity nanoslit mode within a waveguiding length <10 μm. The CNP can be either freestanding or on-chip by using a tapered fiber or planar waveguide for input-coupling, with a coupling efficiency up to 95%. Within the slit region, the output diffraction-limited nanoslit mode offers an extremely confined optical field (∼0.3 nm × 3.3 nm) with a peak-to-background ratio higher than 25 dB and can be operated within a 200-nm bandwidth. The group velocity dispersion of the nanoslit mode for ultrafast pulsed operation is also briefly investigated. Compared with the previous lasing configuration, the waveguiding scheme demonstrated here is not only simple and straightforward in structural design but is also much flexible and versatile in operation. Therefore, the waveguiding scheme we show here may offer an efficient and flexible platform for exploring light–matter interactions beyond the nanometer scale, and developing optical technologies ranging from superresolution nanoscopy and atom/molecule manipulation to ultra-sensitivity detection.

针对船舶舱内复杂空间材料表面除锈需求，利用脉冲光纤激光清洗平台开展了EH36船用钢板激光清洗工艺参数优化与清洗后材料表面性能实验研究。通过宏观、微观形貌观测与表面化学成分分析，并结合船舶行业除锈标准规范，建立了船用钢激光除锈质量评价准则，以此确定了材料激光除锈最佳工艺参数。在此基础上开展激光除锈后材料表面质量、显微硬度、粗糙度及综合力学性能测试评估。研究结果表明：在最佳除锈工艺参数(平均功率210 W、重复频率250 kHz、脉冲宽度300 ns、扫描速度4000 mm/s)下，船用钢板表面质量达到Sa2.5等级，力学性能基本保持不变，能够满足船舶舱内复杂空间材料表面除锈工艺要求，在船舶修造材料表面除锈领域具有优良的适用性。