种子注入高重频单纵模全固态激光器技术研究
文献类型：学位论文
| 作者 | 王君涛 |
| 学位类别 | 博士 |
| 答辩日期 | 2012 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 朱小磊 |
| 关键词 | 全固态激光器 种子注入 单纵模 谐振探测技术 腔内倍频 |
| 其他题名 | Research on high repetition rate of injection seeded single frequency DPSSL |
| 中文摘要 | 直接探测多普勒测风激光雷达技术是目前国内外激光雷达研究和应用领域的热点之一，多普勒测风激光雷达系统对激光光源的输出性能参数提出了很高的要求，不但要求单纵模调Q激光脉冲具有一定的能量，而且要求输出的单纵模激光脉冲具有良好的频率稳定性。本论文研究工作针对测风激光雷达的应用需求，开展了种子注入高重频单纵模全固态激光器技术研究，研究内容主要包括端面泵浦的1kHz重复频率种子注入单频激光器、高效的腔内倍频绿光单频脉冲激光器和正弦扫描谐振探测技术的理论仿真等三个方面的内容。 论文第一章首先简单介绍了单频激光器在多普勒测风激光雷达中的应用，以及用于测风激光雷达的单频脉冲光纤激光器和单频脉冲全固态激光器的进展，并简单回顾了种子注入技术的基本理论。 第二章介绍了实现种子注入的三种基本技术方法：建立时间最小化方法，改进的Pound-Drever-Hall方法和谐振探测方法。重点介绍了谐振探测方法的工作原理和谐振探测技术方法的一系列演化。 第三章介绍了LD端面泵浦种子注入激光器实验工作。着重开展了100 Hz、250 Hz和1000 Hz三种典型重复频率下种子注入振荡特性研究，获得了近衍射限的稳定单频激光脉冲输出。在100Hz和250Hz这两个低重频下，实现了10mJ脉冲能量及约10ns脉宽的激光输出。在1000Hz重频下，由于增益介质出现了较严重的热效应，最大输出能量只有8.8mJ，脉冲宽度11ns，光光效率为15.9%。激光束在水平和竖直两个方向上的光束质量分别为1.30和1.31，一个小时内的能量不稳定度小于1.5%。利用输出激光脉冲和Mephisto OEM200激光器进行拍频，测量脉冲激光的线宽和频率稳定性。2分钟内的绝对频率稳定性（rms）为3.5MHz ，线宽平均值为54.2MHz，接近傅里叶转换极限。 第四章介绍了一种结构紧凑高效率的腔内倍频单频532nm绿光脉冲激光器。创新地将种子注入技术与腔内倍频技术结合，直接在振荡器中获得高转换效率的绿光单频激光输出。实验比对了种子注入激光器中用LBO晶体和KTP晶体的倍频效果。在I类相位匹配的LBO腔内倍频种子注入激光器中，实现了4.8mJ的单频脉冲绿光输出，相应的从808nm泵浦光到绿光的光光效率为9.6%。激光光束在水平和竖直方向的光束质量测量值分别为1.42和1.33，一小时内的输出能量的不稳定性小于1%。 第五章提出了一种新的正弦扫描机制的谐振探测方法，以期进一步提高种子注入单频激光器的频率稳定性和抗干扰能力。针对论文提出的正弦扫描谐振探测方法，进行了模拟仿真计算，结果显示，正弦扫描机制能很好的实现腔长的精确反馈控制，并具备在从动腔腔长和种子光频率匹配的瞬间提取出Q开关触发信号的能力。 |
| 英文摘要 | The direct detection Doppler wind lidar technology is one of the research focus in lidar application at home and abroad. The lidar system imposes special requirements on the single frequency pulse laser, not only high pulse energy but also high frequency stability. To meet these requirements, research on high repetition rate injection seeded single frequency diode pumped solid state laser is carried on. Three parts are presented, including end pumped 1000 Hz injection seeded single frequency laser, intracavity frequency doubling injection seeded single frequency green laser, and simulation on resonance detection with sinusoidal scan voltage. In chapter one, the application of single frequency laser in Doppler wind lidar is introduced briefly, and the development of the single frequency fiber laser and single frequency DPSSL is followed. Finally the theory of injection seeding is reviewed. In chapter two, 3 techniques to realize stable injection seeding is presented, including build-up time minimization, modified PDH and resonance detection. More attention is paid to the principle and evolution of the resonance detection. In chapter three, end pumped injection seeded single frequency laser is realized, especially at the pulse repetition rate of 100 Hz, 250 Hz and 1000 Hz, and near diffraction-limited laser output are all obtained. At 100 Hz and 250 Hz, the pulse energy of 10 mJ is achieved with the pulse width of 10 ns. At 1000 Hz, due to the thermal effect in YAG rod, although the single frequency is remained, the single pulse energy is decreased to 8.8 mJ with a pulse width of 11 ns. At this maximum output, the optical-optical efficiency is 15.9% and the measured M2 value are 1.30 and 1.31 at horizontal and vertical direction respectively. The instability of pulse energy is less than 1% over 1 hour. Optical heterodyne with Mephisto OEM200 laser was adopted to measure the spectral width and absolute frequency stability of the laser pulse. The frequency jitter is less than 3.5 MHz (rms) over 2 min, and the mean linewidth is 54.2 MHz, which is near the limit of Fourier transform. In chapter four, the combing of injection seeding and intracavity frequency doubling provides a compact high efficiency 532 nm laser output. In the experiment, the characteristic of LBO and KTP is compared. Green laser with single pulse energy of 4.8 mJ is obtained by intracavity frequency doubling, using type I phase matching LBO. The efficiency from 808 nm pump source to 532 nm laser is 9.6%. The measured value of M2 are 1.42 and 1.33 respectively in horizontal and vertical direction. The instability of pulse energy is less than 1%. In chapter five, in order to increase the frequency stability and anti-jamming capability in the injection seeded laser, a new resonance detection method with sinusoidal scan voltage is designed. Simulation calculation shows that the cavity length could be compensated accurately, and the Q-switch trigger is abstracted when the cavity length is matched well with seeder frequency. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15716]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 王君涛. 种子注入高重频单纵模全固态激光器技术研究[D]. 中国科学院上海光学精密机械研究所. 2012. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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