Fabrication of hydrophobic structures on coronary stent surface based on direct three-beam laser interference lithography

To solve the problems with coronary stent implantation, coronary artery stent surface was directly modified by three-beam laser interference lithography through imitating the water-repellent surface of lotus leaf, and uniform micro-nano structures with the controllable period were fabricated. The morphological properties and contact angle (CA) of the microstructure were measured by scanning electron microscope (SEM) and CA system. The water repellency of stent was also evaluated by the contact and then separation between the water drop and the stent. The results show that the close-packed concave structure with the period of about 12 μm can be fabricated on the stent surface with special parameters (incident angle of 3°, laser energy density of 2.2 J?cm-2 and exposure time of 80 s) by using the three-beam laser at 1 064 nm, and the structure has good water repellency with CA of 120°.     

Schmidt结构的改进型龙虾眼光学透镜研究

龙虾眼光学是解决大视场高能射线聚焦的关键技术。从成像光学的视角考察了龙虾眼光学系统的成像原理,制作完成了基于Schmidt结构的改进型龙虾眼光学透镜原理样机,并对该系统在可见光波段的性能进行了测试。该龙虾眼透镜由厚度为300 m的抛光铝板作为反射工作面,反射面成扇形排布,并具有完全对称的球形结构;反射面间夹角由特殊加工的角间距27.6'的楔板保证。原理样机的有效焦距为65 mm,中心张角为17.4817.48,其在空间各个方向上的成像能力几乎相同,可以满足空间大视场探测系统的任务需求。     

940 nm LD泵浦Yb∶CN 978 nm激光器及其二次谐波

报道了半导体泵浦Yb∶CaNb2O6晶体输出978 nm波长的激光器。泵浦模块采用了940 nm LD,在实现了Yb∶CaNb2O6薄盘激光器1.14 W的连续波输出的基础上,采用LBO非线性晶体进行内腔倍频实现了151 mW的489 nm连续二次谐波输出,在水平和垂直方向上的光束质量因子M2分别为1.11和1.13。