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题名	超短激光脉冲源信噪比提升相关技术研究
作者	李妍妍
学位类别	博士
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	冷雨欣
关键词	时域信噪比 超强超短激光脉冲 光学参量放大 双光束泵浦 中红外激光源
其他题名	Research on ultrashort laser pulse temporal contrast enhancement and related techniques
中文摘要	超强超短激光技术的发展使强光场甚至超强光场可以在实验室中产生，可为人类创造出前所未有的综合性的实验室尺度极端物理条件。通过在极端物理条件下对物质结构、运动及相互作用的研究，人类对客观世界规律的认识将更加深入和系统化。因此，目前国际上各个国家正在竞相发展拍瓦乃至10拍瓦量级的超强超短激光技术。利用超强超短激光装置产生的聚焦光场强度可达1022W/cm2，并有望突破1026W/cm2的超高量级。在这种强甚至超强光场下，激光与各种物质间的相互作用进入到了一个前所未有的高度非线性与相对论性的新范畴，使得激光脉冲时域信噪比（定义为主脉冲强度与预脉冲或是卫星脉冲的强度之比）的重要性越来越突出。针对日益增长的强场乃至超强场激光物理等前沿研究的需求，如超强超短激光与特定固体物质相互作用产生高能质子等，目前国际上已发展了一系列超强超短激光脉冲时域信噪比提升新技术，其中双啁啾脉冲放大技术路线是当前主流之一，而发展大能量超高时域信噪比的超短激光脉冲源是其核心技术之一。 本论文围绕超强超短激光脉冲源时域信噪比提升相关技术开展研究，主要是针对钛宝石和钕玻璃作为工作介质的超强超短激光技术发展的需求，发展了大能量、宽带宽、高信噪比乃至载波包络相位稳定（CEP）可控的超短激光脉冲源新技术，以及开展了中红外波段激光源研究。本论文主要取得了以下创新成果和研究进展： 1.提出并验证了CEP稳定的1053nm飞秒强激光信噪比提升新技术，利用光学参量放大技术获得CEP稳定的2106nm红外飞秒强激光脉冲，并通过倍频技术，实现CEP稳定的1053nm高信噪比超短激光脉冲输出，在主脉冲前2ps处，激光脉冲信噪比达到>1011。由于采用共线结构，光斑质量较好。 2.提出并验证了采用飞秒强激光脉冲进行双光束泵浦的宽带宽光学参量放大新技术。在输出激光脉冲中心波长为2106nm下，两束光单独泵浦时输出能量分别为73μJ、95μJ，两束光同时泵浦时输出能量为240μJ。实验结果表明此技术可以提供相对较高的泵浦能量和激光脉冲输出能量；输出激光脉冲光斑平滑，接近高斯分布；脉冲宽度与两束单独泵浦时类似。 3.发展了高信噪比的800nm超强超短激光脉冲源新技术。结合空心光纤（HCF）技术、交叉偏振波产生技术（XPW）以及光学参量放大技术，获得了800nm/29.5fs/60μJ/1kHz的激光脉冲，光谱全宽>100nm，在主脉冲前~10ps处信噪比达到>1011。 4.采用新型非线性晶体BIBO发展800nm宽带宽高信噪比强激光脉冲源技术。通过光学参量放大技术获得82μJ的1600nm激光脉冲，经过倍频获得脉冲宽度为18.8fs的800nm激光脉冲，光谱全宽约120nm，光谱半宽为53.3nm，相应的傅里叶变换极限脉冲宽度为18.1fs。激光脉冲信噪比在主脉冲前~10ps处达到>1011，在主脉冲前40ps处达到了1012。 5.发展激光二极管泵浦的高效率、宽带可调谐Tm: YAP激光技术，获得当时Tm: YAP激光器最大的调谐范围1894nm-2066nm。
英文摘要	With the rapid development of the ultra intense ultrashort lasers, high field even ultrahigh field can be generated in the laboratory; extreme high field ultrafast lasers can create unprecedented comprehensive laboratory scale extreme physics. The human understanding of objective world will be deeper and more systematic with the research under extreme physical conditions. Now, every country in the world is competing for the development of PW even 10 PW level ultraintense ultrashort laser techniques. The focus density of high power laser system has reached >1022 W/cm2, and it will be >1026 W/cm2 in future. Temporal contrast of ultraintense ultrashort laser pulse has been a key parameter for researches in the high or ultrahigh field laser experiments. Based on the increasing development requirement of high or even ultrahigh laser physics, such as generation of high energy proton in the interaction between ultraintense ultrashort laser and special bulk matters, a series of temporal contrast enhancement new techniques have been developed. Double chirped pulse amplification technique is one of the current mainstreams, and the development of high energy ultrahigh temporal contrast is one of its core technologies. The thesis mainly focuses on the ultrashort laser pulse temporal contrast enhancement and related new techniques, such as high energy, broadband bandwidth, CEP-stabilized and mid infrared laser sources. The major innovation results and progresses are listed as below. 1.We proposed and experimentally verified new CEP-stabilized temporal contrast enhancement technique for Nd: glass system, and obtained CEP-stabilized infrared femtosecond laser pulse at 2106nm with optical parametric amplification. Combined with second harmonic generation, we achieved high temporal contrast CEP-stabilized ultrashort laser pulse at 1053nm and the temporal contrast has reached >1011 at 2ps before the main pulse. Because of the collinear structure, the beam profile is good. 2.We proposed and experimentally verified two beam pumped broadband optical parametric amplification new technique with femtosecond laser pulse. With one pump beam, the achieved energy of 2106nm pulse is 73μJ and 95μJ, respectively, while with two pump beam, the energy is 240μJ. The results show that this technique can provide relative higher pump energy and output energy, the beam profile is smooth and close to Gaussian distribution, the pulse duration is similar to that of single pump pulse. 3.We innovation developed 800nm ultraintense ultrashort laser pulse with ultrahigh temporal contrast. Based on the combination of hollow core fiber, cross-polarized wave generation and optical parametric amplifier, the technique can realize the output of 800nm/29.5fs/60μJ/1kHz. The full width of the spectrum is >100nm, the temporal contrast has reached >1011 at ~10ps before the main pulse. 4.We developed 800nm broadband high temporal contrast intense laser pulse with new nonlinear crystal. Based on OPA, we achieved 82μJ at 1600nm. With SHG, we achieved 800nm laser pulse with duration of 18.8fs, full width of spectrum ~120nm, FWHM of spectrum 53.3nm, corresponding FTL 18.1fs. The temporal contrast has reached >1011 at 10ps and 1012 at 40ps before the main pulse. 5.We developed a diode pumped high efficiency and broadband tunable Ti: YAP laser with perfect comprehensive performance. It can be continuesly tuned from 1894nm to 2066nm, which is the widest tunable range then.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/15864]
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	李妍妍. 超短激光脉冲源信噪比提升相关技术研究[D]. 中国科学院上海光学精密机械研究所. 2014.

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