非对称激光脉冲与原子相互作用的量子相干调控
文献类型：学位论文
| 作者 | 向阳 |
| 学位类别 | 博士 |
| 答辩日期 | 2010 |
| 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 | 量子相干调控 阈上电离 高次谐波产生 超短脉冲 非线性啁啾 |
| 其他题名 | Quantum Coherent Control of the Interaction between Asymmetric Laser Pulses and Atoms |
| 英文摘要 | The study of the interaction between a intense laser field and the matter is currently being a hot research area in physics. The investigations of high-order harmonic generation and above-threshold ionization, not only enrich our knowledge on strong field physics, but also have important applications in attosecond generation and metrology, the detection of material structure, etc.. In this thesis, we mainly investigate the quantum coherent control of the interaction between asymmetry pulses caused by a nonlinear chirp and atoms by solving the time-dependent Schrödinger equation numerically. The main innovative and important results are listed as follows: 1. Based on the three step model, a novel physical mechanism of the extension of high-order harmonic generation cutoff is explored, i.e., the asymmetry of the combination field causes the extension of the cutoff of high-order harmonic generation. We verify this by investigating the high-order harmonic generation of atoms in the combination of a few-cycle nonlinear chirped laser pulse and static electric field. The asymmetry is enhanced by adjusting the chirping parameters, therefore the cutoff of high-order harmonic generation is significantly extended and an ultra-broad continuum spectrum is obtained. Selecting the continuum spectrum with band-pass filter, a single 10 attosecond pulse can be generated if the phase is compensated for. 2. We explore the high-order harmonic generation in multi-cycle regime. In multi-cycle nonlinear chirped laser pulses, the symmetry of the laser field is broken, therefore the cutoff of high-order harmonic generation is extended and the continuum spectrum appears near the cutoff, from which an isolated attosecond pulse can be generated. Since only the symmetry of the nonlinear chirped laser field in several optical cycles near the pulse center is broken, the duration of attosecond pulse is nearly independent of the duration or chirp form of the drive pulse. 3. The high-order harmonic generation of muonic atoms in super-high intense nonlinear chirped laser pulses is investigated. The muonic atom is made up of a muon and a proton. Due to the large mass of the muon, compared with the ordinary hydrogen atom, the Bohr radius of the munonic atom is much smaller and the ionization potential is much larger. Therefore, the cutoff of high-order harmonic spectrum very large and a super-broad continuum spectrum appears, from which a single zeptosecond pulse can be obtained. 4. We explore the above-threshold ionization of atoms in few-cycle nonlinear chirped laser pulses. The oscillation of laser field is changed by adjusting the nonlinear chirping parameter, and then the process of direct ionization and rescattering of the electron is modified, which causes the variation of the plateau structure and cutoff of the above-threshold ionization spectrum. With the increase of the nonlinear chirp rate, the plateau of high-order above-threshold ionization spectrum disappears gradually, while the cutoff increases significantly. 5. We investigate the photoelectron spectrum of hydrogen atom in few-cycle xuv laser pulses. It is found that the abnormality appears in the photoelectron spectrum: The peak of photoelectron shows red shift compared with the well-known Einstein photo-electric effect formula. The shift becomes large as the pulse duration decreases. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15626]  |
| 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 | 向阳. 非对称激光脉冲与原子相互作用的量子相干调控[D]. 中国科学院上海光学精密机械研究所. 2010. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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