强激光非线性自聚焦效应研究
文献类型：学位论文
| 作者 | 文双春 |
| 学位类别 | 博士 |
| 答辩日期 | 2001 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 范滇元 |
| 关键词 | 自聚焦 小尺度自聚焦 核聚变 高功率激光器 时空不稳定性 超短脉冲 |
| 其他题名 | Research on Self-Focusing of Intense Laser Beams |
| 中文摘要 | 自聚焦是非线性光学中的一个基本物理问题,自非线性光学诞生以来它一直是一个热门课题.在用于惯性约束核聚变(ICF)的高功率固体激光驱动器中,自聚焦是使光束质量变坏和限制输出功率的主要因素,正如美国劳仑斯·利弗莫尔国家实验室(LLNL)的报告所述,自聚焦,特别是小尺度自聚焦,是聚变激光器总体设计、工程研制和安全运行的重要问题.所以,研究自聚焦无论在理论上还是实际应用上都具有十分重要的意义.该论文结合中国ICF驱动器神光Ⅲ装置研制工作的实际需要和自聚焦理论的发展主要开展了如下几个方面的研究工作,获得了若干具有创新性的成果,并在国内外重要学术刊物上发表或即将发表15篇相关论文.第一,根据高功率激光驱动器中光束传输的物理模型自主开发了能模拟光束非线性传输和部分典型的线性传输过程的程序,首次揭示了光束小尺度成丝的若干新规律.第二,研究了介质存在增益(或损耗)、光束强调制及背景光有能量交换等问题,将B-T理论推广到更接近实际工作情况,具有重要的应用意义.第三,研究了非旁轴矢量自聚焦效应,将自聚焦理论进一步拓展到自聚焦点以后,从而丰富和完善了自聚焦理论.第四,系统地研究了非线性色散介质中的时空不稳定性问题,揭示了若干新的不稳定性现象.这些工作对超短脉冲产生、高维时空孤子物理和调制不稳定性物理等具有十分重要的意义. |
| 英文摘要 | Self-focusing is one of the fundamental problems in Nonlinear Optics. It has always been a hot topic since the naissance of nonlinear optics. In high-power solid-state lasers, self-focusing is the major factor for degradation of laser beam and limiting the maximum laser power available. As stated in Lowrence Livermore National Laboratory (LLNL) reports, self-focusing, especially small-scale self-focusing, has always been a significant problem in the total design, engineering development, and safe operation of fusion lasers. Therefore, self-focusing is of very important significance, both theoretically and practically. Taking into consideration the requirement of the preparation of SHENGGUANG III facility in our country and the development of self-focusing theory, we have done some researches on the following four aspects. We have obtained some novel and innovative results, and have published 15 related papers in the important internal or external journals. Firstly, we have independently developed a series of simulation codes based on the physical model for optical beam propagation, especially nonlinear propagation, in high power ICF lasers, and we have, for the first time to our knowledge, disclosed some new laws for beam filamentation. Today's ICF lasers are huger, and thus the investment on them are heavier and the involved physical processes are much more complex. Computer codes that model the propagation of intense laser beams through laser systems become the key roles in the design and analysis of all the ICF lasers. Although a series of computer codes such as PROP92 and so on have been developed in some foreign institutions, these codes are both expensive and confidential, and thus are unavailable for us. Some related codes have also been developed in our country, but these codes are on the basis of the classical Bespalov-Talanov (B-T) theory, which is an ideal model far from practice. Keeping this in mind, we have independently developed a series of simulation codes based on the nonlinear Schrddinger equation. Using the developed codes, we have simulated the filamentation of plane wave and Gaussian beams, and for the first time to our knowledge, numerically extended B-T theory to the case of inhomogeneous background beams. In addition, we have studied the variations of beam quality with B-integral in rod and disk amplifiers. In a disk amplifier, the beam contrast increases sharply for B > 2. These results are in good agreement with NIF experimental results. Most importantly, we have for the first time simulated the filamentatiom of locally modulated beams, and found that the local modulations basically satisfy the local energy conservation law that the local modulations grow mainly by drawing energy from that part of background beam, and thus they don't influence the propagation of the other part of the beam. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15322]  |
| 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 | 文双春. 强激光非线性自聚焦效应研究[D]. 中国科学院上海光学精密机械研究所. 2001. |
入库方式： OAI收割
来源：上海光学精密机械研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。