Lines are induced on the surface of a photosensitive (FOTURAN) glass by focused femtosecond laser transverse writing with scanning velocity in a wide range of 40-1800 μm/s. The formed lines are analyzed using scanning electron microscope (SEM) and optical microscope (OM). It is observed that three distinct morphologies of lines are produced depending on the scanning velocity. Lines written in low velocity level (40-100 μm/s) and high velocity level (1000-1800 μm/s) are uniform and regular, while those written in moderate velocity level (150-600 μm/s) are rough. The influence of scanning velocity is explained based on different pulses overlapping or cumulative dose of laser exposure in irradiated area. Fabrication of shallow groove on the surface is also demonstrated.

为了定量分析飞秒激光金属加工中的热影响，基于一个二维的双温模型，采用有限差分法计算了飞秒激光烧蚀金属镍的径向热影响区。提出一种飞秒激光烧蚀热影响区定义，把热影响区定义为两部分，一部分是熔化再凝固区(晶格温度介于相爆炸温度和熔化温度之间的区域)，另一部分是热激活区(晶格温度介于熔化温度和热激活温度之间的区域)。通过研究表层晶格不同时刻的径向温度分布，得到飞秒激光烧蚀500nm厚金属镍的径向热影响区是160nm。结果表明，飞秒激光加工的热影响区非常小，可以实现对金属材料的超精密加工。并分析了电子热导率和电子比热容对径向热影响区的影响。

采用有限差分法对约化后的双温方程进行数值模拟．研究了飞秒激光与金属铜相互作用时，脉冲形状对烧蚀结果的影响．结果表明：脉冲能量确定时，脉冲形状对烧蚀结果影响不大；多脉冲作用时，脉冲重复频率只有在一定范围内(随材料属性改变)，脉冲间的热累积效应才存在；对传导性好的金属材料，热累积效应不明显．并实验证实了上述结果．

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 'phi'0. From the plot of the accumulated laser fluence N'phi'_(th)(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 are in good agreement with the theoretical calculation.

Ablation experiments with femtosecond (fs) laser pulse (pulse duration 37 fs, wavelength 800 nm) on organic polymers have been performed in air. The ablation threshold is found to be only several nanojoules. The diameters of the dots ablated in the organic polymers are influenced by the laser fluence and the number of laser pulses. It is observed that heat is diffused in a threadlike manner in all directions around the central focus region.Explanations of the observed phenomena are resented. A one-dimensional waveguide is also ablated in the organic polymers.

The Ti:sapphire oscillator is used to realize structural change in an organic glass (polymethyl -methacrylate (PMMA)). Single pulse fluence threshold of PMMA and the relation of the breakdown threshold with different numerical aperture objectives are determined using a formula deduced from an existent equation. Three-dimensional dots in the organic glass is performed at the same time.