飞秒激光在光敏玻璃上制作微凹面

利用聚焦的飞秒激光（中心波长775 nm、脉宽150 fs）照射FOTURAN光敏玻璃,经热处理及浓度为8％的氢氟酸溶液室温腐蚀50 min后,在FOTURAN玻璃表面制作了微凹面.利用原子力显微镜和扫描电子显微镜分析了微凹面的形貌,发现它具有光滑璧面和清晰边缘,直径约为几十微米.通过分别改变入射激光的单脉冲能量(970~3 250 nJ)和脉冲数目(10~3 000个),研究了它们对微凹面制作结果的影响,发现了微凹面的直径随激光入射参量的饱和效应,并解释了其原因;指出了飞秒激光在FOTURAN上制作微结构的应用.     

飞秒激光在光敏玻璃内制作微孔

用20倍显微物镜将波长为775 nm的飞秒激光聚焦在光敏玻璃（FOTURAN）内部,通过纵向写制模式由表面以下500 μm曝光至表面,并结合热处理和在浓度8%的氢氟酸超声溶液中腐蚀50 min,在FOTURAN内部制作了直径为几十μm的微孔.利用光学和扫描电子显微镜分析发现微孔具有圆形横截面和清晰边缘,目前得到的深宽比大约为7.通过在宽范围内改变入射激光能流（2.3~36.2 J/cm2）和写制速度（100~1 000 μm/s）,研究了这两项飞秒激光入射参量对制作微孔的影响.发现写制速度对制作微孔直径影响较小,而利用相对低的入射激光能流曝光可得到较大深宽比的微孔,并且在此情形下制作微孔的横截面更圆,璧面光滑度更高,并分析了原因.     

利用除尘灰制备活性炭的工艺研究

以除尘灰为原料，用物理活化法制备活性炭．研究了活化温度、活化时间、活化剂流量对活性炭性能的影响．实验结果表明，活化温度和活化时间对活性炭的BET比表面积和吸附性能有很大影响；该方法可制得1nm以下微孔和10nm以下中孔均比较发达的活性炭．     

Femtosecond laser ablation of Au film around single pulse threshold

Ablation process of 1-kHz femtosecond lasers (pulse duration of 148 fs, wavelength of 775 nm) of Au film on silica substrates is studied. The thresholds for single and multi pulses can be obtained directly from the relation between the squared diameter D2 of the ablated craters and the laser fluence φ0. From the plot of the accumulated laser fluence Nφth(N) and the number of laser pulses N, incubation coefficient of Au film is obtained to be 0.765. Some experimental data obtained around the single pulse threshold axe in good agreement with the theoretical calculation.     

Aluminum film microdeposition at 775 nm by femtosecond laser-induced forward transfer

Micro-deposit ion of an aluminum film of 500-nm thickness on a quartz substrate was demonstrated by laser-induced forward transfer (LIFT) using a femtosecond laser pulse. With the help of atomic force microscopy (AFM) and scanning electron microscopy (SEM), the dependence of the morphology of deposited aluminum film on the irradiated laser pulse energy was investigated. As the laser fluence was slightly above the threshold fluence, the higher pressure of plasma for the thicker film made the free surface of solid phase burst out, which resulted in that not only the solid material was sputtered but also the deposited film in the liquid state was made irregularly.     

Femtosecond laser microstructuring of nickel foil

We observe the morphological change and grain structure of Ni foil when it is ablated with femtosecond laser pulses. Scanning electron microscopy and field emission transmission electron microscopy are used to study the nature of the morphology and grain structure of nickel foil and determine the essential features. The results indicate that there are many random uanostructures in the center of the ablated region composed of nanocrystalline grains as well as some core-shell structures phase explosion and extremely high cooling rate are the for the formation of surface nanostructures. The observed morphologies seem to suggest that most probable physical mechanisms responsible