基于增益开关技术的高能量脉冲全光纤激光器研究

发布时间：2018-03-09 04:02

本文选题：激光　切入点：脉冲光纤激光器　出处：《上海交通大学》2015年博士论文　论文类型：学位论文

【摘要】：自从上世纪六十年代初世界上第一台红宝石激光器问世以来,激光器作为一种应用广泛的工具已经深刻的影响甚至改变了我们的生活。近年来,光纤激光器在工业市场中大放异彩,已经取代了部分传统的Nd:YAG固体激光器和CO_2激光器。光纤本身的狭长构型,使得光纤激光器非常容易获得高平均功率。然而,同样是由于这一构型,导致传输其中的激光功率密度较高易于积累非线性效应,不利于获得高的峰值功率和单脉冲能量。正因为存在这样的问题,研究者们尝试各种方法以从光纤激光器中获得高脉冲能量和峰值功率,成为了近年来得研究热点。本课题旨通过发展在光纤激光器中尚未被大量应用的增益开关脉冲产生方法,以获得高脉冲能量的全光纤激光器。本课题的研究内容和所获得的主要成果包括:1)通过模拟计算给出了增益开关铒镱共掺光纤激光器的时域和能量域特征,为此类激光器的实验研究提供重要的参考依据;2)采用理论模型计算研究了同带泵浦增益开关掺铥光纤激光器的时域特征,确定了获得类高斯脉冲的泵浦条件并给出了不同激光器配置时输出脉冲时域特征变化;3)采用数值模拟计算研究了掺铥光纤激光器在采用不同泵浦跃迁、输出高达千瓦功率时的激光特性和热效应,提出了级联泵浦掺铥光纤激光器的设计思路并计算了预期结果;4)构建了采取全新的混合泵浦构型的增益开关掺铥光纤激光器的实验装置,获得高达230微焦的单脉冲能量输出,比已有文献中报道的结果提高了一个数量;5)采用一个同带泵浦的增益开关掺铥光纤激光器作为种子源,构建了2微米波段的全光纤主功率振荡放大器,获得了脉冲能量高达7毫焦的纳秒激光输出,这在全光纤2微米纳秒脉冲光纤激光器中是最高的;6)采用实验和理论相结合的方法研究了增益开光光纤激光器中的类锁模现象的起源,确定其始于多个激光纵模之间的拍频,并通过未被泵透的掺铥光纤自身的饱和吸收效应得以稳定和加强。7)提出了一些各种用途的光纤激光新构型概念设计,并已申请发明专利对其进行保护。
[Abstract]:Since the world's first ruby laser came out in early -40s, lasers, as a widely used tool, have profoundly influenced and even changed our lives in recent years. Fiber lasers have replaced some of the traditional Nd:YAG solid-state lasers and CO_2 lasers in the industrial market. The long and narrow configuration of the fiber makes it very easy for fiber lasers to obtain high average power. It is also due to this configuration that the higher laser power density in the transmission tends to accumulate nonlinear effects, which is not conducive to obtaining high peak power and monopulse energy. Researchers have tried various methods to obtain high pulse energy and peak power from fiber lasers, which have become a hot topic in recent years. In order to obtain all-fiber lasers with high pulse energy, the main research contents and main results obtained in this paper include: 1) the time-domain and energy-domain characteristics of gain-switched erbium-ytterbium co-doped fiber lasers are given by simulation. This paper provides an important reference for the experimental study of this kind of laser. The theoretical model is used to calculate and study the time domain characteristics of the Thulium doped fiber laser with the same band pump gain switch. The pumping conditions for obtaining Gao Si like pulses are determined and the time-domain characteristic variations of output pulses with different laser configurations are given. Numerical simulation is used to study the different pumping transitions of thulium doped fiber lasers. Laser characteristics and thermal effects when output power is as high as kilowatt, The design idea of cascade pumped thulium doped fiber laser is put forward and the expected results are calculated. An experimental device of gain-switched thulium doped fiber laser with a new mixed pump configuration is constructed, and the single pulse energy output of up to 230 microcoke is obtained. An all-fiber main power oscillator amplifier with 2 micron band is constructed by using a gain-switched thulium doped fiber laser pumped in the same band as seed source. The nanosecond laser output with a pulse energy of up to 7 nanosecars has been obtained. This is the highest in all fiber 2 渭 m nanosecond pulsed fiber lasers. The source of mode-like locking in gain open-light fiber lasers is studied by combining experiment and theory, and the beat frequency between longitudinal-mode laser is determined. Through the saturated absorption effect of unpumped thulium doped fiber to stabilize and strengthen. 7) some new conceptual designs of optical fiber laser with various applications have been put forward and have been protected by patent of invention.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN248

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