周期量级超短脉冲激光在二能级原子介质中的光谱特性研究
文献类型：学位论文
| 作者 | 刘炳欣 |
| 学位类别 | 硕士 |
| 答辩日期 | 2005 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 龚尚庆 |
| 关键词 | 自感透明 载波拉比振荡 高频成分 脉冲链 相对相位 |
| 其他题名 | Spectral Effects of ew-cycle Ultrashort Pulse Laser Propagating in Two-Level Atom Medium |
| 中文摘要 | 目前周期量级超短脉冲激光与原子、分子的相互作用已经成为光与物质相互作用的研究热点。我们以半经典理论为基础，通过有限时域差分法和预校正法对麦克斯韦一布洛赫方程进行精确求解，来研究周期量级超短脉冲激光在二能级原子介质中的传播特性。本论文系统进行了周期量级超短脉冲激光、超短脉冲链以及双色场在二能级原子介质中光谱特性的研究。攻读硕士学位期间，我的科研工作主要获得以下几个方面的成果：1．研究了超短脉冲链在二能级原子介质中的光谱特性。发现由于脉冲间的相干效应，即使是2π脉冲链，载波拉比振荡也能使得高频成分产生，而且高频成分的产生强烈依赖于脉冲间的相位差和时间间隔。2．探讨了周期量级超短脉冲激光在高密度二能级原子介质中的光谱特性新规律。在高密度下，即使是2π超短脉冲，自感透明现象已不能再现。随着原子密度的增加，光谱也发生很大变化：光谱发生分裂，光谱的蓝移（高频成分）和红移（低频成分）发生，中心频率光谱逐渐消失。3．探讨了双色场在非共振二能级原子介质中光谱的新特性。发现由于双色场间的干涉效应，高频成分产生。对于基频和不同倍频的双色场，可以产生基频奇数倍或者偶数倍不同的分立峰值的光谱。 |
| 英文摘要 | The interaction of few-cycle ultrashort pulse laser with atoms and molecules is currently being a hot subject in the research of the light-matter interaction. Based on semiclassed theory, we investigate the property of few-cycle untrashort pulses propagating in two-level atom medium by employing a standard finite-difference time-domain approach for solving the full Maxwell equations and predictor-corrector methord to solve the Bloch equations. In this thesis, we make a fundamental research on spectral effects of few-cycle ultrashort pulse, ultrashort trains and two-color pulses propagating in the two-level atom system systematically. The main works results of my master thesis are shown as follows: We investigated the spectral effects of femtosecond pulse trains propagating in a two-level atom system. We found even for a In femtosecond pulse train, that higher spectral components can be produced because of carrier-wave Rabi floppings. The total electric field changes with the relative phase and delay time due to interference effect. So spectral effects depend crucially on both the relative shift and the delay time between the successive pulses of the femtosecond pulse train. We studied new characteristics of ultrashort pulses propagating in a dense two-level atom system. The self-induced transparency (SIT) can't be recovered even for In ultrashort pulses. With atomic densities increasing, new features such as pulse splitting, redshift and blueshift of the corresponding spectra arise and the spectral component of central frequency gradually disappears. 3. We also studied the spectral property for two-color ultrashort pulses propagating in a nonresonant two-level medium. Due to the interference effect of the In two-level pulses, carrier-wave Rabi floppings arise which lead the production of higher spectral components. For two-color pulses with second or third harmonic field of fundamental pulse field, the higher components show differently distinct peaks. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16467]  |
| 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 | 刘炳欣. 周期量级超短脉冲激光在二能级原子介质中的光谱特性研究[D]. 中国科学院上海光学精密机械研究所. 2005. |
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。