基于啁啾脉冲的超快全光分幅成像技术研究

发布时间：2017-12-27 12:08

本文关键词：基于啁啾脉冲的超快全光分幅成像技术研究　出处：《中国工程物理研究院》2016年硕士论文　论文类型：学位论文

【摘要】：超快物理过程、超快化学过程、超快生物过程等领域的研究都需要极高的时间分辨能力。为了突破传统高速摄影技术中的机械转动结构和电子学系统带宽的限制,并克服泵浦探测、超快体全息分幅成像、超快多色差分幅、序列时间映射全光分幅等技术的不足,本文提出了一种基于离散取样分幅记录的超快全光分幅成像方法。这种成像方法可实现：(1)全光分幅成像；(2)同轴分幅成像；(3)更多画幅数记录；(4)相干相位成像。本文围绕设计方案中的几项关键技术：脉冲展宽技术、脉冲整形技术、脉冲测量技术、离散取样分幅记录技术进行了研究,主要内容如下。对几种典型的脉冲展宽器进行了对比分析,选择了平行光栅对展宽器作为本项目的展宽方案。对脉冲展宽系统进行了数学建模和仿真分析,并搭建系统开展了实验研究,实验结果表明该方案可实现约10ps的脉冲展宽。对几种典型的脉冲整形技术进行了对比分析,选择了反射式液晶空间光调制器的4f脉冲整形系统作为本项目的整形方案。对脉冲整形系统进行了数学建模和仿真分析,重点对液晶空间光调制器的像素间隙、阶梯型相位调制以及非线性色散三个影响因素带来的整形失真情况进行了分析,并对整形系统进行了优化设计。搭建了反射式LC-SLM型4f脉冲整形系统,对液晶空间光调制器灰度相位关系进行了标定,实现了相位的精确控制。对几种常用的超短脉冲测量技术进行了对比分析,提出了基于窗口傅里叶变换的频域干涉测量技术。利用该技术对线性啁啾脉冲和复杂拍频信号的啁啾特性进行了测量,并将实验结果与传统频域干涉测量法所得结果进行了对比分析,验证了测量方案的可行性。设计了离散取样分幅记录系统,并利用仿真软件进行了光线追迹,验证了设计方案的可行性。搭建验证性实验光路,开展了激光光斑和分辨力板成像的分幅记录,并对系统的空间分辨力、时间分辨力、相位信息提取能力等指标进行了评估分析。结合脉冲展宽和脉冲整形部分的研究结论,计算了基于啁啾脉冲的超快全光分幅系统可实现的理论指标。
[Abstract]:Ultra fast physical processes, ultrafast chemical processes, ultra fast biological processes, and other fields require very high time resolution. In order to break through the traditional high-speed photography technology in the mechanical rotation system and electronics system bandwidth constraints, and overcome the shortage of pump probe, ultrafast holographic framing, ultrafast multi color framing, framing time sequence mapping all-optical technology, this paper proposes a method of framing ultrafast all-optical discrete sampling points records based on. The imaging method can be achieved: (1) all optical amplitude division imaging; (2) coaxial amplitude division imaging; (3) more picture number recording; (4) coherent phase imaging. This paper focuses on several key technologies in the design, including pulse widening technology, pulse shaping technology, pulse measurement technology and discrete sampling and amplitude recording technology. The main contents are as follows. Several typical pulse stretchers are compared and analyzed, and the broadening scheme is selected as the broadening of the broadening device. The mathematical modeling and simulation analysis of the pulse broadening system is carried out, and the system is built for experimental research. The experimental results show that the scheme can achieve pulse width of about 10ps. Several typical pulse shaping technologies are compared and analyzed. The 4f pulse shaping system of reflective liquid crystal spatial light modulator is selected as the shaping scheme of this project. The pulse shaping system for mathematical modeling and simulation analysis, the key to bring plastic clearance, pixel liquid crystal spatial light modulator ladder type phase modulation and nonlinear dispersion of three factors of distortion is analyzed, and the optimized design of shaping system. A reflective LC-SLM type 4f pulse shaping system is set up. The phase relation of the liquid crystal spatial light modulator is calibrated, and the precise phase control is realized. Several commonly used ultrashort pulse measurement techniques are compared and analyzed, and a frequency domain interferometry based on window Fourier transform is proposed. The chirped characteristics of linear chirped pulse and complex beat signal are measured by this technology, and the experimental results are compared with the results obtained by the traditional frequency-domain interferometry, which verifies the feasibility of the measurement scheme. The discrete sampling and recording system is designed and the ray tracing of the simulation software is used to verify the feasibility of the design scheme. A validated experimental optical path was built, and the laser spot and resolution plate imaging were recorded. The spatial resolution, time resolution and phase information extraction ability of the system were evaluated and analyzed. Combined with the research conclusions of pulse broadening and pulse shaping, the theoretical indexes of the ultra fast all optical amplitude splitting system based on chirped pulse are calculated.
【学位授予单位】：中国工程物理研究院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN78

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