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题名	多光子脉冲内干涉相位扫描技术研究
作者	赵冠凯
学位类别	硕士
答辩日期	2014
授予单位	中国科学院上海光学精密机械研究所
导师	李儒新，刘军
关键词	MIIPS，LC-SLM，SHG，频率啁啾
其他题名	Investigations of Multi-photon Intra-pulse Interference Phase Scan
中文摘要	飞秒激光脉冲由于其超短的时域宽度和超强的峰值功率，而在超快时间分辨光谱、飞秒化学、飞秒生物学和强场激光物理等领域获得了广泛的应用。飞秒激光脉冲的频谱形状和相位分布直接决定着它的脉冲形状和相位。特定光谱和相位形状的飞秒激光脉冲在选择性双光子吸收，泵浦探测实验，原子、分子和固态系统的相干量子控制等技术中都起着至关重要的作用。因此，对飞秒激光脉冲的频谱相位测量与整形就显得非常重要。 本论文主要研究基于多光子脉冲内干涉相位扫描技术的飞秒激光脉冲测量与整形技术。在众多的飞秒激光脉冲测量技术中, 多光子脉冲内干涉相位扫描(Multi-photon Intra-pulse Interference Phase Scan, MIIPS)是目前已知的唯一一种既可以测量飞秒激光脉冲频谱相位又可以补偿和调制飞秒激光脉冲频谱相位及频谱强度的方法。这个优势使其能够在液晶空间光调制器的调制范围内得到几乎任意的光谱幅度和相位形状。这对飞秒化学，飞秒生物学等领域的相关研究具有重要的意义。 本论文的主要研究内容如下： 1、详细分析了多光子脉冲内干涉相位扫描理论，编写MIIPS模拟程序。首先研究了不同的相位啁啾对飞秒脉冲激光MIIPS轨迹图的影响，从而建立了一种MIIPS轨迹图形状与待测飞秒激光脉冲啁啾类型与大小的直观联系；然后研究了频域半高全宽分别为80nm和30nm的飞秒激光脉冲在五种不同的频率啁啾条件下的MIIPS轨迹演化过程，从而对MIIPS理论有了更加深入的理解；同时引出了MIIPS的局限性及其误差来源，并据此从理论上提出了改进方案，即Gated-MIIPS，并对该方法做了理论分析。 2、深入研究了SLM-S640d的相位与振幅控制原理，提出了一种新的液晶板像素与对应波长的定标方案；编写LabVIEW程序控制SLM-S640d和光纤光谱仪完成定标和MIIPS轨迹图的测量。 3、搭建完成了一套完整的基于液晶空间光调制器(Liquid Crystal Spatial Light Modulator, LC-SLM)的飞秒激光脉冲测量与整形系统。通过实验对MIIPS方法中正弦相位参量α 和γ进行了优化选择研究，这不仅对更好的利用MIIPS方法进行飞秒激光脉冲相位测量和补偿提供指导，而且可以通过选取合适的参量获得整形和窄化的倍频光谱(Second Harmonic Generation, SHG)。根据优化的正弦相位参量，我们利用MIIPS方法通过三次迭代还原出了中心波长≈810nm，重复频率为1kHz，极限脉宽≈32fs的飞秒激光脉冲的光谱相位，测量精度在±0.1rad以内。根据测量结果，我们通过液晶空间光调制器对补偿后的飞秒激光脉冲施加特定的正弦相位扫描调制，得到了光谱宽度约2nm的连续可调的倍频光谱。这一装置将在多光子显微成像、脉冲整形、飞秒激光光谱学等众多领域发挥重要作用。
英文摘要	Because of its ultra-short pulse width and ultra-high peak power, femtosecond laser pulse has been extensively used in ultrafast time-resolved spectroscopy, femtosecond chemistry, femtosecond biology and high field laser physics. The shape of a femtosecond laser pulse is directly determined by the amplitude and phase in frequency domain. Custom-tailored femtosecond laser pulses are of vital importance in the technologies like two-photon absorption, pump-probe experiment, and coherentcontrol of atom, molecular and solid state systems. As a result, the measurement and shaping of a femtosecond laser pulse is in urgent need. In this dissertation, Multi-photon Intra-pulse Interference Phase Scan method is deeply researched. As far as we know, MIIPS is the only method which can measure and compensate femtosecond laser pulses at the same time. This advantage makes it possible to obtain almost arbitrary spectral amplitude and phase under the limitation of a LC-SLM, which is of strategic importance in the field of femtosecond chemistry and femtosecond biology. The main points of this dissertation are list as follows: An intensive study and a robust simulation program are made on the MIIPS theory. Firstly, MIIPS traces with different frequency chirp are studied, which can establish a visualized relationship between the MIIPS trace and frequency chirp. Secondly, two kinds of femtosecond laser pulse, whose spectral width are respectively 80nm and 30nm, are simulated to generate MIIPS trace at five different frequency chirps. By analyzing the MIIPS trace at different chirps, we understand the MIIPS theory and its limitations deeply. Then, Gated-MIIPS is proposed to overcome the limitations of the original MIIPS method. How to control the spectral phase and amplitude of a femtosecond lase pulse by using the SLM-S640d is studied in detail. A new calibration scheme between the liquid crystal pixel and the wavelength is proposed. Home-developed LabVIEW programs are used to drive the SLMS-640d and a fiber spectrometer to fulfill the task of calibration and MIIPS method. A femtosecond laser pulse measurement and compensation system is developed in this dissertation based on a LC-SLM. The effects of the modulation parameters (α and γ) are studied in detail for the optimization of MIIPS. This not only provides a reference for the phase measurement and compensation in MIIPS, but also supplies a method for the narrowing and shaping SHG spectrum. With the optimized parameters, we get the spectral phase of the frequency-chirped femtosecond laser pulses with only 3-times’ iteration. The femtosecond laser pulse，whose transformed limited pulse width is about 32fs, is centered at 810nm and has a repetition of 1kHz. The accuracy of our measurement is less than±0.1rad. A special sinusoidal phase is imposed on the SLM after the compensation of the chirped femtosecond laser pulse. Continuously and tunable SHG with spectral width less than 2nm is obtained .The device will be useful in many fields, for example, multi-photon microscopy, pulses shaping, and femtosecond laser spectroscopy etc.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/16873]
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	赵冠凯. 多光子脉冲内干涉相位扫描技术研究[D]. 中国科学院上海光学精密机械研究所. 2014.

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