【作者】 白晋涛；

【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， 2001， 博士

【摘要】 本论文第1章首先回顾了全固态激光器的发展历史过程，介绍了半导体泵浦的全固态激光器的主要特性以及各类LD泵浦的晶体材料及其特性，综述了国内外激光二极管泵浦的各种波长全固态激光器的研究进展，展望了全固态激光器的应用前景；第2章引入了LD泵浦固体激光器的基本模型和工作原理，从速率方程导出四能级系统的振荡阈值，工作斜效率和工作点情况，继而描述了三波耦合理论和腔内倍频非线性过程；第3章对全固态二极管双端泵浦Nd：YVO₄／KTP（LBO）激光器技术进行了描述，给出在大功率泵浦下热透镜效应对腔稳定性的影响及如何优化热稳腔的腔结构和腔参数等；第4章主要介绍了各种飞秒固体激光增益介质及其特性，进行了全固态近红外飞秒激光理论分析和实验研究；第5章介绍了飞秒激光二次谐波产生（SHG）理论，分析和计算了利用棱镜组引进频谱空间啁啾来补偿谐波倍频晶体的相位失配，进行了全固态Ti：S飞秒蓝光、紫外光激光器的实验研究：论文第6章主要研究了全光纤飞秒激光脉冲的产生和放大机制及其关键技术，理论与实验相结合，重点解决了自启动锁模和光脉冲的孤子压缩效应的机制和实现自启动锁模的关键技术。具体研究内容和创新工作为： 1．理论上通过引入端面泵浦光场与振荡光场的分布函数，得到稳态条件下输入输出特性，分析了泵浦光焦点位置对泵浦阈值及斜效率的影响和在不同泵光功率下的最佳光斑大小及透过率。对腔内倍频理论也进行了研究，讨论了影响倍频效率的几个因素，如相位失配、走离效应等。在此基础上，重点讨论了由大功率LD泵浦的热稳腔的稳定性问题，通过数值模拟计算，分析了腔长、束腰大小等因素对腔稳定性的影响，这对优化腔结构、选择光路参数，保证大功率连续波绿光激光器能够稳定运转，具有一定的指导意义。 2．采用两只输出功率为12W，波长为810nm的半导体激光器作Nd：YVO₄腔内倍频激光器的泵浦源，通过数值计算设计了高稳定的热不敏激光腔结构。使激 光腔中的热透镜焦距范围在 5——1000mm之间激光器仍能稳定地工作。从而研制成 功了一套可用作泵浦掺钛兰宝石激光器的全固体绿光激光器。 3．为了降低掺钛兰宝石激光器的阈值提高它的光一光转换效率，我们利用 光学传输矩阵理论，对掺钛兰X石激光腔进行数值模拟，设计出工作阈值低、转换 效率高的飞秒激光系统。当绿光泵浦功率为Z＊w时，输出的飞秒激光平均功率达 到 300mw。 4．在飞秒蓝光、紫外光激光产生方面，从理论上研究了用非线性晶体产 一生飞秒激光h次谐波机制。由于飞秒激光具有宽的光谱带宽，一般在50120urn 之间，如果采用常用相位匹配技术，不能在宽的光谱范围内获得最佳的相位匹配。 在飞秒光脉冲的宽光谱的条件下，如何能较好地满足相位匹配是研究工作要解决的 关键问题和关键技术。根据激光经过色散元件之后，光谱在空间按一定的顺序排列 这一特性。我们通过选取适当焦距的透镜在较宽的光谱范围内成功地实现了相位匹＿配。通过数值模拟确定了最佳透镜焦距。实验证明该技术能有效地提高转换效率， 利用BBO倍频晶体可获得飞秒蓝光激光转换效率为24．3％，输出的飞秒蓝光激光 平均功率达75mw，脉宽为33．3fs。同时初步进行了飞秒钛宝石自锁模激光器的三 次谐波产生的实验研究。本论文这一研究成果拓展了飞秒激光波长范围，使飞秒激 光器可同时输出近红外光仿00七30n叫、蓝光和紫外光。 5．与他人合作研究了全光纤飞秒激光脉冲的产生和放大机制及其关键技 术。理论与实验相结合，重点解决了自启动锁模和光脉冲的孤子压缩效应的机制和 实现自启动锁模的关键技术，采用非线性偏振旋转脉冲相加锁模自启动技术研制成 的半导体激光器泵浦的掺E／光纤环形腔激光器，获得了最短脉冲269B、重复率 ZI．37 MHz、中心波长 1．53pm且工作稳定的激光脉冲；同时采用高增益掺 Ery光纤 放大器对掺E；许光纤激光器输出的超短光脉冲直接进行放大得到了最大平均输出 功率14．smw、单脉冲能量0．69InJ、峰值功率2657．SW、最短光脉冲宽度260fs 的好结果。更多还原

【Abstract】 In this thesis, the development history process of all-solid-state lasers is reviewed in Chapter 1 firstly. The main characters of diode-laser pumped solid-state laser and all kinds of LD-pumped crystal material characters are introduced. The research evolution of LD pumped different wavelength all-solid-state lasers domestically and abroad has been summarized. The prospect of all-solid-state lasers is forecasted. In the Chapter 2, the basic model and work principle of LD-pumped all-solid-state lasers are induced. The oscillation threshold of four-level system , working slope efficiency and working point condition are deduced from rate equation theory. Also three-wave-coupling-theory and intracavity frequency-doubling nonlinear process are described. In the Chapter 3, all-solid-state two-end-pumped Nd:YVO4/KTP(LBO) laser technique is described. The infection of stability under high power pumped thermal lens effect, how to optimize thermal stability cavity configuration and cavity parameter are given. In the Chapter 4, all kinds of gain mediums of all-solid-state femtosecond laser and their characters are mainly induced. Theory analysis and experiment research of all-solid-state infrared femtosecond laser are studied. In the Chapter 5, the second harmonic generation (SHG) theory of femtosecond laser is introduced. The compensating of phase mismatching in doubling-crystal is analyzed and calculated by using spectrum spatial chirp of prism series. The experiment is carried out for all-solid-state Ti:S femtosecond blue and ultraviolet lasers. In the final chapter, thepivotal technique for the generation and amplifier of all-fiber femtosecond laser pulse is studied. The mechanism and pivotal technique of self-start-mode-locked andlaser pulse soliton compress effect are solved by theory and experiment. Concrete research contents and innovation as follows:1. The characteristics of input and output in the case of stable condition is obtained by introducing distributive function of end-pumping field and oscillating field in the theory. Not only pumping threshold and slope efficiency depending on the focus position of pumping light, but also the optimal spot size and efficiency of permeation are analyzed. The theory of intracavity frequency-doubling also is investigated. In addition, we have discussed several elements affecting the efficiency of frequency-doubling such as phase mismatch and walk-off effect etc. The stability of thermal cavity duo to high-power LD pumping is discussed particularly. After numerical simulative calculating, some elements such as cavity length and waist size that have some influence on the stability of cavity are analyzed. It has a certain significance for optimizing the configuration of cavity, choosing the parameter of light path and guaranteeing the high-power green laser output.2. Two LDs which have 12W output power and 810nm wavelength are used as the pump sources of intracavity frequency-doubling Nd:YVO4 laser. High stable configuration of non-sensitive for thermal laser cavity is designed according to numerical calculation. Thus laser can operate stably with thermal lens focus length between 5mm and 1000mm in the cavity. So a kind of all-solid-state green laser used as pump source of Ti:Sapphire laser is developed successfully.3. In order to decrease the threshold and to improve the light-light conversion efficiency of the Ti: Sapphire laser, we make numerical simulation in the Ti:S laser oscillator with the standard ABCD matrix and design an low operation threshold and high conversion efficiency femtosecond laser system. A femtosecond infrared laser averageoutput power of 300 mW is obtained with the pump green laser power of 2.5 W.4. In the case of femtosecond blue and ultraviolet laser, the mechanism of femtosecond laser second harmonic wave generation with nonlinear crystal is researched in theory. Owing to the wide bandwidth (usually between 50nm and 120nm )of femtosecond laser, the optimal phase matching could not be obtained(during such wide bandwidth更多还原