双光子直写技术凭借其高精度、任意三维结构刻写、高成本效益、材料设计高自由度等特点，已被成功应用到多种微纳光学器件的刻写中。基于双光子直写的微纳光学器件应用不断拓展，对刻写分辨率和通量都提出了更高的需求。超分辨激光纳米直写和高通量激光直写技术使得双光子直写具有nm级精度与cm级尺寸的跨尺度加工能力，进一步拓展了基于双光子直写的微纳光学器件研究领域。本文首先对双光子直写原理进行概述，介绍本课题组在利用双光子直写技术制造衍射光学器件、光纤集成器件方面的研究进展；然后，介绍本课题组在使用超分辨激光直写技术制备纳米光子器件方面的拓展研究，并展示了高精度、高通量激光直写技术在大面积刻写微纳光学器件上的技术优势。

In this report, we demonstrate a novel technique for the microscopic patterning of gold by combining the photoreduction of AuIIIBr4 - to AuIBr2 - and the electrochemical reduction of AuIBr2 - to elemental gold in a single step within solution. While mask-based methods have been the norm for electroplating, the adoption of direct laser writing for flexible, real-time patterning has not been widespread. Through irradiation using a 405 nm laser and applying a voltage corresponding to a selective potential window specific to AuIBr2 -, we have shown that we can locally deposit elemental gold at the focal point of the laser. In addition to demonstrating the feasibility of the technique, we have collected data on the kinetics of the photoreduction reaction in ethanol and have deduced its rate law. We have confirmed the selective deposition of AuIBr2 - within a potential window through controlled potential electrolysis experiments and through direct measurement on a quartz crystal microbalance. Finally, we have verified local deposition through scanning electron microscopy.

从超疏水理论出发，基于三种典型的基本润湿性模型揭示了材料表面粗糙度与固液接触面积对于制备超疏水表面的重要性。在此基础上，综述了直接激光写入（DLW）、直接激光干涉图案化（DLIP）以及激光诱导周期性表面结构（LIPSS）方法各自的优缺点。其中：DLW方法利用高能激光束对材料表面进行烧蚀，具备较高的自由度，能在各种材料表面构建任意三维结构，但其表面加工精度较差，难以建立多层次结构；DLIP方法利用多个相干激光形成的干涉图案对材料表面进行有选择的去除，能形成更精细的周期性三维微纳米分级结构；LIPSS方法可在材料表面获得大量空间周期在数百纳米的波纹结构，但加工时间较长。最后，从制备参数、表面结构形貌以及疏水性能等方面对不同的超疏水表面制造方法进行了归纳，并对其研究现状及发展方向进行了分析和探讨。

为解决在激光直写系统中利用数字微镜器件(DMD)无法对纵向像素数大于768的灰度图像进行滚动显示的问题,文章在其控制电路的数据传输、存储及显示驱动技术方面开展了研究。利用FPGA中丰富的逻辑资源实现了图像数据传输方式的改进,通过移位寄存器对数据进行拆分和位宽转换。提出间隔存储方法实现大尺寸灰度图像数据的存储,基于此方法可实现灰度图像滚动显示时的数据读取。同时,省去在上位机中进行位平面拆分和图像分割的预处理步骤,简化了上位机操作流程并提高了系统数据传输效率。实验结果表明,该系统能够以419.6Hz的刷新率对大尺寸灰度图像进行滚动显示。

完美涡旋光束的涡旋半径与拓扑荷数无关,且携带有轨道角动量,这使得完美涡旋光束在光学通信、量子光学以及激光制造等领域被广泛应用。利用双光子聚合的激光直写技术制备出了可产生完美涡旋光束的径向相移螺旋型波带片。通过改变波带片的径向相移控制参数,实现了对完美涡旋光束涡旋半径的调控。同时,通过干涉图样验证了涡旋光束携带的轨道角动量与设计的拓扑荷数相吻合。本工作可为光子芯片集成的快速设计制造提供一定参考。

Direct growth and patterning of atomically thin two-dimensional (2D) materials on various substrates are essential steps towards enabling their potential for use in the next generation of electronic and optoelectronic devices. The conventional gas-phase growth techniques, however, are not compatible with direct patterning processes. Similarly, the condensed-phase methods, based on metal oxide deposition and chalcogenization processes, require lengthy processing times and high temperatures. Here, a novel self-limiting laser crystallization process for direct crystallization and patterning of 2D materials is demonstrated. It takes advantage of significant differences between the optical properties of the amorphous and crystalline phases. Pulsed laser deposition is used to deposit a thin layer of stoichiometric amorphous molybdenum disulfide (MoS₂) film (～3 nm) onto the fused silica substrates. A tunable nanosecond infrared (IR) laser (1064 nm) is then employed to couple a precise amount of power and number of pulses into the amorphous materials for controlled crystallization and direct writing processes. The IR laser interaction with the amorphous layer results in fast heating, crystallization, and/or evaporation of the materials within a narrow processing window. However, reduction of the midgap and defect states in the as crystallized layers decreases the laser coupling efficiency leading to higher tolerance to process parameters. The deliberate design of such laser 2D material interactions allows the selflimiting crystallization phenomena to occur with increased quality and a much broader processing window. This unique laser processing approach allows high-quality crystallization, direct writing, patterning, and the integration of various 2D materials into future functional devices.