基于大增益带宽和高热导率晶体的偏振复用激光技术可以提高双频激光器和双光梳激光器在输出光谱范围和功率方面的性能。本文提出一种基于Yb:CALGO晶体的偏振复用激光器。将两片与光轴成45°角切割的双折射晶体放置在增益晶体的前后两侧形成三明治结构，利用双折射晶体的偏振特性使腔内激光形成只在三明治结构部分具备空间分离其余部分共线的偏振方向互相垂直的两种模式。同时，这种三明治结构既能使单束泵浦光能够自动分离为两束空间分离匹配的泵浦光，也可以使腔内增益晶体放置在腔内模式腰斑位置处，与泵浦光达到更好的模式匹配，提高光泵浦效率。最终测得的激光输出功率达到瓦量级并且斜率效率超过30%。在腔内加入标准具后，实现了频差为太赫兹量级的稳定双频激光运转。

We report a Yb-doped mode-locked fiber laser based on a nonlinear amplifying loop mirror (NALM), which is all-normal-dispersion (ANDi), and allows the output wavelength to be tunable. The laser can generate a stable femtosecond dissipative soliton with a maximum output power of 196 mW. Its repetition rate is 112.4 MHz, and the final pulse duration is 236 fs. By adjusting the angle of the reflective diffraction grating, the mode-locked fiber laser was realized to tune the output with a tuning range of 54 nm from 1011.8 nm to 1065.6 nm. To the best of our knowledge, this is the widest tuning range of an ANDi Yb-doped mode-locked fiber laser based on NALM.

Such as, by using the photothermal effect of materials, the surface tension of the lubrication layer on the surface of materials can be changed, thus creating a wetting gradient force to push the droplets to move. Further, the sliding and pinning of the droplet can be controlled by the phase change of the paraffin layer on some functional surfaces. The pyroelectric crystal can generate the dielectric force field on its surface based on the photothermal effect, which could be applied to realize the lossless moving, merging, and splitting of the droplets. In addition, the wettability of the photovoltaic crystals could be changed with the irradiation of light, therefore, can be used to control the behavior of droplets. In this paper, the development of the photo-responsive functional surface in droplet manipulation was briefly reviewed. The mechanisms of the droplet manipulation with the functional surface were expatiated. The categories of functional surfaces were summarized, the characteristics of the structure were analyzed, and the corresponding implementation method was introduced in detail. In addition, the applications of the photo-responsive functional surface in droplet transportation, fusion, and segmentation were introduced. Finally, the future development and potential applications of the photo-responsive functional surface for droplet manipulation were prospected.

基于光纤环形激光器，设计出由三端口环形器、偏振控制器、未泵浦保偏掺镱光纤和光纤布拉格光栅组成的滤波器件作为高精度滤波器对谐振腔内的模式个数进行抑制，通过调谐偏振控制器，在保偏掺镱光纤内形成的梳状光谱和动态光栅，实现了窄线宽、单、双波长可切换单频掺镱光纤激光器。单波长运行时，在1064.37 nm处测得激光器输出线宽346 Hz，光信噪比大于50 dB，30 min内该激光器波长及功率的不稳定性均在0.01 nm和0.2 dB范围内。通过调节偏振控制器，单波长和双波长可以实现互相切换，双波长分别位于1064.156 nm和1065.236 nm。该技术为超窄线宽激光器的双波长输出提供了新的途径。

针对目前微纳针形结构加工中存在的精度、形貌、可控性等问题，基于飞秒激光双光子加工系统中的单个体素，通过引入一维倾角自动调控体素的空间位置，提出了一种简单高效的加工连续渐变微纳针形结构的方法。通过开展加工实验，成功地在光刻胶材料中加工出了一系列长度可控、形貌连续渐变的微纳针形结构。实验结果表明：基于本方法加工的微纳针形结构，其高度呈线性变化关系且针尖形貌渐变精度达到了纳米量级，结构横向线宽渐变连续且沿中轴线呈对称分布；针形结构顶端最小高度达到5 nm，横向最小线宽为195 nm。其在功能表面、微纳流控、生物传感等研究领域具有潜在的应用价值。

微纳尺度流动现象广泛存在于生命科学、界面科学、微纳芯片技术以及材料科学等领域，微纳流体测速技术是研究微纳尺度流动现象及其应用的基础。本文首先介绍了几种主要的微流体测速技术，包括显微粒子图像速度计、粒子追踪速度计、分子标记速度计、光学相干层析技术、磁共振成像测速技术等。然后，详细介绍一种新型的光学微纳流体速度测量技术——激光诱发荧光漂白测速技术，该技术同时具有非侵入性、远场测速、纳米级高时空分辨率等优点，适应目前微纳流控实际研究中对高时间分辨率和高空间分辨率的迫切需求；重点介绍了基于该技术所取得的一些研究成果，包括对微流体电动力湍流和非线性交流电渗流等非稳态、非线性流动等现象和规律的最新研究成果。最后，对该技术进一步的发展进行了展望。