【作者】 倪晓昌；

【导师】 王清月；

【作者基本信息】 天津大学 ， 光学工程， 2004， 博士

【摘要】 本论文对飞秒激光应用于微纳加工领域进行了部分理论与实验研究工作。论文的主要内容包括：一、采用几种不同模型实现飞秒激光与金属、电介质以及聚合材料作用过程的描述。对金属材料，通过数值分析约化后的双温模型，对飞秒激光与金属材料相互作用过程进行研究，确定了电子与晶格的耦合时间，并与长脉冲情形进行比较，同时又考虑了脉冲串对材料作用结果的影响；对电介质材料，通过飞秒激光在电介质内传输模型的表述，考虑飞秒激光的时空传输特性，对等离子体产生过程进行分析以及模型设计，并与长脉冲情形做了比较。二、从脉冲形状出发，分析高斯形飞秒激光与烧蚀孔径横向尺度的关系：若用ρ表示脉冲能量降为脉冲中心峰值能量E0一半时的光束半径，Et表示材料出现烧蚀时的阈值能量。那么烧蚀孔半径r与ρ的关系为可以表示为：r2＝ρ2(lnE0－lnEt)，实验中采用针孔扫描法探测了所用飞秒激光的光斑形状。同时采用光束传输模型，实现了飞秒激光在透明材料内部加工光学器件的模型设计，使得飞秒激光加工具有特定参数的微光学器件成为可能。三、对飞秒激光加工光学平台以及光学显微系统进行测试，实现飞秒激光加工平台的搭建，并对所用飞秒激光器各项参数对光束质量的影响因素进行了测试；为获得足够多的实验信息，采用几种探测方法实现烧蚀监测及焦点横向定位，提出了适用于加工薄片形透明材料的相干探测方法，实现了焦点纵向定位。四、塑料光纤在降低损耗和提高带宽方面取得的突破性进展，使得其在宽带短距离通信网络中具有显著竞争力，相应的带动了塑料光纤相关微光学链接器件研究热潮。实验对飞秒激光与常用的塑料光纤芯材料（PMMA,PC）相互作用机理进行了研究，并最终实现了该有机材料内部微光学器件的刻划。同时实验观察到飞秒激光在有机材料内产生的一些非线性现象，并给出了相应的实验分析。更多还原

【Abstract】 In this dissertation, part of theoretical and experimental studies on the application of femtosecond laser in micro-nanomachining field are presented. The main contents in this dissertation are classified as follows.After several different models are deduced, it is realized to describe the process of the interaction of the femtosecond laser with metal, polymer and dielectric materials.To describe femtosecond laser interaction with metal, the Double-Temperature Equation(DTE) was formatted simply. The electron-lattice couple time is determined through the numerical simulation, which is compared with long pulse. And at the same time, the effect of multi-pulse action is studied. For femtosecond laser interaction with polymer materials, the time-space character of laser must be considered. After the model of femtosecond laser transmission in dielectric is described, the process of plasma generation is studied. And the analysis work is carried out by comparing with long pulse case at the same time. 2、From the sharp of the laser pulses, the correlation of the gaussian pulses with the ablation transversal radius is performed: r2＝ρ2(lnE0－lnEt), in which the ρis the spatial radius of the pulse when the energy is down to the 1/e times of the peak energy E0, the Et is energy threshold when the ablation occurred, and the r is the ablation radius. The femtosecond laser speckle has been measured with pinhole scan method in this dissertation. The beam propagation model is also introduced. With the model, the electro-optic components can be designed. Then it is possible that the micro-optic components with special parameters are fabricated by femtosecond laser.3、After femtosecond laser optical machining stages and microscope system are tested, the femtosecond laser micromachining system has been set up successfully. And the factors of femtosecond laser that may have effects on the laser beam quality are measured. To obtain much more information of ablation and the locality of focal point, several detector methods are used. At the same time, coherent detector method is presented to determine the locality of focal point in the lognitudinal direction, which is suitable for the wafer materials. <WP=6>4、The development of the plastic optical fiber(POF), which is particularly to reduce fiber loss and increase the bandwidth, make the POF have the prominent compete ability in short distance and wide bandwidth aspect. Then micro-optic connectors of the POF becomes the hot research item. The interaction mechanism of the femtosecond laser ablation on core materials of POF(PMMA,PC) has been studied in the dissertation. Finally, it is realized that same micro-optic components have been fabricated by using femtosecond laser in the polymer materials. At the same time, some non-linear phenomena have been observed when the femtosecond laser transmitted in the polymer materials, and the corresponding analysises are given.更多还原