正弦位相调制的飞秒偏振整形脉冲的相干控制研究

发布时间：2018-04-08 07:14

本文选题：相干控制　切入点：整形飞秒激光脉冲　出处：《吉林大学》2017年硕士论文

【摘要】：整形飞秒激光脉冲对原子分子体系各种动力学过程的量子相干控制一直是人们重点关注的研究领域。我们采用正弦位相调制下的偏振整形脉冲诱导N_2O分子的电离,并通过改变正弦位相参数A、T、ф的值实现了对N_2O分子的电离过程的量子相干控制。首先,我们研究了相同ф,不同A条件下的T扫描以及相同T,不同A条件下的ф扫描,实验结果发现A值的变化改变了子脉冲的相对强度,而未改变T扫描以及ф扫描下N_2O母体离子强度随T、ф变化曲线的变化规律,只是改变了曲线的整体强度。因此,三脉冲序列作用下,子脉冲相对强度的变化未影响N_2O分子电离过程随其它参数的变化规律。然后我们研究了不同ф,相同A条件下的T扫描。研究发现N_2O分子电离过程随脉冲间距出现周期性振荡,对于ф值不同的三脉冲序列,N_2O分子电离过程随脉冲间距周期性振荡的规律有所不同,不同ф值导致这种周期性振荡存在一定的位相差。我们分析认为相邻子脉冲之间光学振荡的位相差以及偏振方向的不同导致周期性振荡规律的差别。同时我们还研究了不同T,相同A条件下的ф扫描。我们提出正弦位相调制下整形激光脉冲的光谱聚焦效应导致了N_2O母体离子强度的周期性振荡。我们还研究了正弦位相调制的整形脉冲作用下,Xe原子电离过程随正弦位相参数A、T、ф变化情况。实验结果表明,正弦位相调制下整形脉冲同样能够实现对Xe原子电离过程的相干控制。
[Abstract]:Shaping femtosecond laser pulses for the quantum coherent control of various dynamical processes of atomic and molecular systems has been the focus of attention.The polarization shaping pulse of sinusoidal phase modulation is used to induce the ionization of N _ 2O molecule, and the quantum coherent control of the ionization process of N _ 2O molecule is realized by changing the value of the sine phase parameter A _ (T).First of all, we study the T scan under the same condition, different A condition and the same T and different A condition. The experimental results show that the change of A value changes the relative intensity of the sub-pulse.However, the variation of N2O ion intensity with T, T, T and T scan was not changed, but the overall strength of the curve was changed.Therefore, the variation of relative intensity of subpulses does not affect the variation of the ionization process with other parameters of NSTs under the action of three pulse sequences.Then we studied the T scan under the same A condition.It is found that the ionization process of N2O molecules oscillates periodically with the pulse spacing, and the periodic oscillation law of the ionization process with the pulse spacing is different for the three-pulse sequence with different values.Different values lead to the existence of certain phase differences in the periodic oscillations.We consider that the phase difference of optical oscillation between adjacent sub-pulses and the difference of polarization direction lead to the difference of periodic oscillation law.At the same time, we also studied the scanning under different T, the same A conditions.We propose that the spectral focusing effect of shaping laser pulse under sinusoidal phase modulation results in periodic oscillation of ion intensity of Ns _ 2O matrix.We also study the ionization process of Xe atoms under the shaping pulse of sinusoidal phase modulation.The experimental results show that the shaping pulse under sinusoidal phase modulation can also achieve coherent control of the Xe atom ionization process.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O561

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