【作者】 程光华；

【导师】 陈国夫；

【作者基本信息】 中国科学院研究生院（西安光学精密机械研究所） ， 光学， 2004， 博士

【摘要】 飞秒激光脉冲提供了一种极强极高的电场能够超过价带电子的束缚力，使分子、原子的电子体系发生巨大变化。在这个过程中，飞秒激光显示出与皮秒、纳秒脉冲不同的特性，如热影响区域小、作用效果能够超过光学衍射极限、优秀的空间选择特性等，这些特性在许多领域有着重要的应用价值，如超精细加工、微光子器件制造、医学精密手术、高密度三维光存储等。本文首先研究了钛宝石增益开关调Q二倍频激光器和钛宝石飞秒激光脉冲再生放大器，并用该放大器研究了飞秒激光脉冲诱导熔融石英折射率改变的机理，以及展开了三维光数据存储、光栅制作、波导制作方面的应用研究。 在激光器方面，最优化激光参数和非线性晶体参数，补偿了来源于激光晶体、非线性晶体和其他的腔内元件的热效应，最终建立了一台高效率的钛宝石调Q二倍频紫外激光器。另外，设计和建立了一台适用于飞秒激光超精细加工的“无展宽器的钛宝石啁啾脉冲再生放大器”。通过优化放大腔结构参数和采用高光束质量的泵浦激光，依靠放大器腔内各个元件的色散展宽种子脉沖，用钛宝石作为增益介质，采用长焦距的凹面镜并将钛宝石晶体离焦有效的克服了激光损伤问题，获得了高效、结构紧凑、光束质量好的飞秒脉冲激光放大系统。 在飞秒激光微加工方面，理论分析了飞秒激光折射率改变区域大小和激光参数的关系以及不同材料的损伤机理，建立了一套飞秒激光微加工平台，实验研究了飞秒激光三维光数据存储的串行、并行写入和串行、并行读出的可行性。尝试光波导、光栅的制造，发现飞秒激光制作的光学原件具有双折射特性，以及飞秒激光诱导各向异性介质的重结晶和各向异性微爆现象。更多还原

【Abstract】 An intense femtosecond laser pulse can provide an electric field strength which exceeds the electric field force of valance electrons that holds the electrons to their ionic cores. Compared with picosecond, nanosecond laser pulse, a femtosecond laser pulse shows excellent advantages such as little or no thermal affected zone, the break of optical diffraction limit and space-selection. Based on those virtues, femtosecond laser pulse can be used many fields, for example, ultra-precision machining, the fabrication of micro- photonic devices, nano-operation in bioengineering and biatrology, and three dimensional optical storage. This thesis ranges over Ti:sapphire laser techniques and frequency conversion, Ti: sapphire regenerative femtosecond amplification and its applications. And the thesis is focused on the mechanism of refractive index changes of fused silica induced by femtosecond laser pulse, and resulting applications such as three dimensional optical storage, the fabrication of grating and waveguide.About Ti:sapphire laser techniques and frequency conversion, the optimum design about the parameters of oscillator and nonlinear crystals was investigated, and the compensation for thermal effect coming from nonlinear crystal and elements in oscillator. Then a Ti:sapphire femtosecond amplifier without stretcher using for micro- machining and optical storage was built. The stretch of seed pulse resulting from the components dispersion in cavity, the off-focusing Ti:sapphire crystal and TEMoo mode pumping laser contribute to a compact, efficient regenerative amplification.In femtosecond laser micro-machining, the dependence of the refractive index changes on the laser parameters was investigated theoretically. A micromachining system has been built. The writing and reading of bits in parallel and bit-by-bit are demonstrated in 3-dimension in transparent materials with fs laser pulse. The writing of an internal diffraction grating and waveguide in optical glass plate is demonstrated using low-density plasma formation excited by a high-intensity femtosecond Ti:sapphire laser, birefringence in those elements, and vaporization and re-crystallization of anisotropy crystal material were observed in the process of micro-explosion due to the expansion of high temperature plasma.更多还原