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High order harmonic generation ( HHG), as one of nonlinear phenomena of intense lasers-atom/ molecular interactions, is a hot topic in recent years.

高次谐波，作为强激光脉冲与原子分子相互作用的非线性现象之一，近年来一直是国内外科学家研究的热点。

The behavior of an atom in strong laser field and the dynamic process of high-order harmonic generation ( HHG) are analyzed with the quantum theory and saddle-point method.

利用量子力学理论和鞍点方法，细致地研究了高次谐波辐射光子的能量与激光相位的关系。

The different pulse-shape may change the cut-off order and spectrum intensity of HHG simultaneously.

不同的脉冲形状会导致高次谐波的截止频率和谱线强度的变化.

These main contents and conclusions of our work are: ( 1) The laser parameter influence on time-frequency of HHG in a two-colour laser pulse have been investigated.

本论文包括以下几个内容：（1）研究了双色场驱动下原子高次谐波的时频特性以及激光参数波动的影响。

It is well-known that the interaction of intense laser field with atoms and molecules can lead to high-order harmonic generation ( HHG). Coherent sources of radiation in XUV and x-ray regions can be obtained by HHG.

当高强度的激光场与原子或分子相互作用时可以产生高次谐波，人们可以利用高次谐波获得相干极紫外高频段辐射源XUV和X射线源。

A Scheme for Simultaneous Extension and Enhancement of the HHG Plateau The relation between sampling frequency and considered harmonic power is derived.

大幅度地展宽和抬高高次谐波平台的新方案导出了交流采样频立与所考虑高次谐波之关系。

In this thesis, the influences of the propagation effects to the HHG have been investigated, and the results show that the propagation effects can be used to improve the temporal characteristics of the harmonics and produce isolated broadband attosecond ( as) pulses.

本文从理论上研究激光脉冲及高次谐波在非线性气体介质中传播的传播效应对高次谐波产生的影响，发现可以利用传播效应来进一步改善高次谐波的时域特性，从而产生宽带单阿秒脉冲。

The most attractive one is high order harmonic generation ( HHG), which can be used as a source of extreme ultraviolet ( XUV) and soft X-ray lasers.

其中高阶谐振的产生，由于可以作为产生真空远紫外线和软X射线的可能途径，受到人们的极大关注。

The series of results indicate that there is a certain relationship between the ionization probability and the pulse shape, which in turn influences the character of HHG.

结果表明脉冲形状和电离率之间有着确定的关系，电离率反过来又影响了谐波谱的性质；

The time-dependent Schrodinger equation of realistic hydrogen atom in intense laser field and static electric field is solved by split-operator method, and the abnormal behaviors of high-order harmonic generation ( HHG) in intense laser field is investigated, which is caused by a static electric field.

利用分裂算符方法数值求解了真实氢原子在强激光场和静电场作用下的含时薛定谔方程，研究了静电场对强激光场中氢原子产生高次谐波的影响。

It is indicated that in SDR the digestive function is affected directly and the endocrine function indirectly ( including hypothalamus_hypophysis_ gonad axis, i.e., HHG axis), while in KDR, HHG axis is affected directly.

结果表明脾虚直接影响消化系统功能，间接影响内分泌功能（包括下丘脑－垂体－性腺轴，即HHS轴功能），而肾虚直接影响HHS轴功能；

The control of quantum path has applications in a wide range, which include high order harmonic generation ( HHG) and attosecond pulse production, the ultrafast imaging in biology, tomographic imaging of molecular orbitals and molecule alignment.

量子轨道的操控有着极为广泛的应用，这包括高次谐波及阿秒脉冲的产生，生物学的快速成像，分子轨道断层成像，分子排列等等。

Alignment of linear molecules by ultrashort laser pulses has great effects on the ionization and high-order harmonic generation ( HHG) in laser fields.

线性分子在超短脉冲激光场作用下的排列对其电离和发射高次谐波有重要的影响。

The experiment results show that gas pressures and the position of gas cell have great influences on HHG from CO2. Finally, the dissertation sums up all of the research work.

实验表明，气体的压强和气体盒与激光焦斑的相对位置都会对CO2分子的高次谐波产生影响。最后，对全文的研究内容作了总结。

In the case of larger internuclear distance, the contribution to HHG from the inner shell will become larger and larger, apart from that from HOMO orbits.

研究发现，当核间距变大时，除了HOMO轨道对谐波发射贡献外，内壳层轨道的贡献也越来越大。

Simultaneous Extension and Enhancement of the HHG Plateau by Using Combined Laser Pulse Irradiating on a United Two-Atom System

利用组合激光脉冲辐照联合两原子体系同时展宽和抬高高次谐波平台

We study the effects of pulse shape and static electric field on ionization and high order harmonic generation ( HHG) of a one dimensional model hydrogen atom.

采用数值方法研究静电场和不同的激光脉冲对氢原子的电离率和高次谐波的影响。

The plasma induces the broadening and blue shift of the HHG spectra, which provides a method for fine-tuning the harmonic wavelength.

等离子体还引起高次谐波光谱变宽蓝移，利用该光谱变化可以实现高次谐波的波长调谐。

To better understand the physical origin of HHG enhancement and attosecond pulse emission, we perform classical analysis and the time-frequency analysis.

为了更好的理解高次谐波展宽与阿秒脉冲发射的物理过程，我们还对该过程进行了经典分析和时频分析。

Three-dimensional numerical calculation shows that plasma plays a significant role in the phase matching process of HHG in a supersonic gas jet with short medium length.

结合强场近似模型和光场传输的三维数值模拟结果表明，在超声喷射条件下，气体介质很短，等离子体在高次谐波相位匹配过程中起主导作用。

In this realm, the interactions of ultrafast intense laser with atoms and molecules lead in a series of interesting and novel highly nonlinear phenomena, such as above threshold ionization ( ATI), nonsequential double ionization ( NSDI), high-order harmonic generation ( HHG) and Coulomb explosion.

在该区域内，超短强激光与原子分子相互作用，呈现出一系列有趣且新颖的高度非线性物理现象，如阈上电离、非顺序双电离、高次谐波辐射产生、库仑爆炸等。

In this thesis, adopting the time-dependent Hartree-Fock scheme, the HHG process of acetylene molecule is systematically investigated.

本文利用含时哈特里一福克方案，系统地研究了乙炔分子的高次谐波发射过程。

High-order harmonic generation ( HHG) can be observed as the molecular system is radiated by an intense laser field, and utilizing the molecular HHG, one can image the orbital wave-function of the molecule.

强激光辐照分子体系可以观察到高次谐波发射，利用分子的高次谐波发射可以对分子的轨道波函数信息进行成像。

We show that the efficiency of high-order harmonic generation ( HHG) in two-color laser field can be enhanced, and analyze the mechanism of the enhancement of HHG.

数值结果显示添加6倍频光的双色激光场能使高次谐波转化效率明显提高。

High harmonic generations ( HHG) in atoms, molecules and nanostructures open a new field in nonlinear optics.

在原子、分子和纳米材料中的高次谐波为非线性光学开辟了一个崭新的研究领域。

The HHG is not only a promising way to produce extreme ultraviolet coherent light source and attosecond pulses, but also an efficient tool to probe microscopic ultrafast processes.

这是由于高次谐波不仅是产生极紫外相干光源以及阿秒超快辐射的重要途径，而且也是实现微观动力学过程探测的有力工具。

Henderson became part of HHG, a new UK holding company listed on the London and Sydney Stock Exchanges.

亨德森成为新成立的英国控股公司HHG的一部分。HHG在伦敦和悉尼上市。

The superposition of an appropriate sub-plateau can give single attosecond soft X-ray pulse, and the effect of HHG from ion has been eliminated through the band selection.

通过选取合适的子平台进行频率叠加，在消除了离子的高次谐波的影响后，可以获得单个的阿秒软X射线脉冲。

High harmonics generation ( HHG) from Ne atom driven by a multi-cycle 43 fs laser pulse is investigated.

研究了多个光周期的长脉冲（43fs）激光与氖原子相互作用产生的高次谐波的辐射特性。

By using wavelet transform, the emission of HHG in different time is obtained.

利用小波变换，观察了高次谐波在不同时刻的发射情况。