【作者】 刘莹；

【导师】 刘杰；

【作者基本信息】 山东师范大学 ， 光学， 2011， 硕士

【摘要】 目前,全固态激光器以其独特的优势在激光领域中占主要地位,在军事国防、科学研究、通讯科技、工农业生产和医疗机械等领域都有广泛应用,在激光领域中占有极其重要的地位。激光晶体作为众多激光介质中的一种,因为其结构上的完整性以及其物理参数上的广泛性,使得它有着层出不穷的性质,成为激光介质中最有前途的种类之一。掺钕激光晶体因为是较早被使用的激光晶体之一,直到现在一直都有着广泛的应用。本论文就是以掺钕激光晶体为研究对象,用二极管泵浦全固态激光器作为泵源,通过不同的调制方式,从理论和实验两个方面实现了二极管泵浦Nd:YAG晶体1064 nm声光调Q、Cr⁴⁺:YAG饱和吸收体被动调Q和声光-被动双调Q激光器的运转输出;用尖晶石(Co²⁺:MgAl₂O₄)可饱和吸收体作为被动调Q晶体,实现Nd:GdVO₄晶体1.34μm被动调Q激光器的运转输出以及使用单壁碳纳米管（SWCNTs）作为可饱和吸收体,Nd:YVO₄晶体作为增益介质,实现高功率高效率的连续锁模运转激光器的实验研究。目的就是为了探究掺钕激光器的脉冲输出特性,得到更窄脉冲、更高峰值功率、更高效率和更高稳定性的脉冲输出。主要内容概括如下:1.介绍三种常用于二极管泵浦全固态激光器的激光晶体:Nd:YAG、Nd:GdVO₄和Nd:YVO₄以及三种饱和吸收体:Cr⁴⁺:YAG、Co²⁺:MgAl₂O₄和SWCNTs的机械性能、热性能和光学特性。并简要概括了他们在二极管全固态激光器中的研究现状以及应用现状。2.用二极管泵浦全固态激光器作为泵源,用Nd:YAG晶体作为增益介质采用不同方式进行1064 nm脉冲激光输出的实验研究。首先以调Q技术基本理论作为基础,采用声光调Q、Cr⁴⁺:YAG被动调Q和声光-Cr⁴⁺:YAG双调Q三种方式分别进行实验,实验均采用平凹腔设计。实验结果证明,双调Q方式可以更好的压缩脉宽,获得窄脉宽、高峰值功率的脉冲输出。最短脉冲宽度为8 ns,对应平均输出功率为1.894 W,最大峰值功率为23.6 kW。3.以1.34μm被动调Q理论为作为基础,采用Co²⁺:MgAl₂O₄可饱和吸收体作为被动调Q元件,用二极管泵浦全固态激光器作为泵源,通过实验实现了对Nd:GdVO₄晶体1.34μm的脉冲激光输出特性的实验研究。实验采用平凹腔的简单结构,通过三种不同透过率的输出镜对激光输出进行比较分析,并对实验出现的现象进行理论分析,最终得到了最短脉冲110 ns的激光输出。4.以锁模技术作为理论基础,用SWCNTs这种新型饱和吸收体作为被动锁模元件,用二极管泵浦全固态激光器作为泵源,进行了Nd:YVO₄/SWCNTs连续锁模激光器脉冲激光输出特性的实验研究。本文还对产生锁模的条件进行了理论计算,在理论上证明:此实验装置在泵浦功率达到一定值时可以产生连续锁模激光输出。在泵浦功率为12 W,重复频率为96 MHz的条件下,得到了脉冲宽度为7.6 ps,平均输出功率为3.6 W,峰值功率为4.9 kW的高功率、稳定的连续锁模激光输出。更多还原

【Abstract】 Diode-pumped solid-state lasers have become a focus in the field of lasers research. Because they have many advantages, such as high stability, high efficiency, high power, compactness, and long lifetime and so on. They have been widely used in many fields such as military, scientific research, medical treatment, and photoelectrics industry and so on. In this paper, we have made experimental research around diode-pumped solid state doped with neodymium by the two methods of Q-switched and mode-locked. We have achieved the aim of laser pulse with short duration, high efficiency, high peak power, high stability. The main content can be generalized as follows:1. We introduced the properties of laser crystals doped with neodymium such as Nd:YAG, Nd:GdVO₄, Nd:YVO₄. Cr⁴⁺:YAG, Co²⁺:MgAl₂O₄ (Co²⁺:MALO) and single-walled carbon nanotubes （SWCNTs） are three kinds of the saturable absorbers. The properties and the applications of them were introducted. The applications of diode-pumped solid state lasers doped with neodymium are simple reviewed.2. The theory of the Q-switched lasers was given in this paper. A diode-pumped Nd:YAG Q-switched lasers at 1064nm with an acoustic-optical modulator （AO）, Cr⁴⁺:YAG saturable absorber and both of them in the cavity were demonstrated. Under the doubly Q-switched laser operation, the laser generated stable pulse width of 8ns with the average output power of 1.894 W. The maximum peak power was 23.6 kW.3. Basing on the theory of passively Q-switched laser at 1.34μm, passively Q-switched output of a diode-pumped Nd:GdVO₄ laser at 1.34μm by using Co²⁺:MgAl₂O₄ crystal as the saturable absorber was demonstrated. Compared with the pulse characteristics by using different transmissions of output mirror, we have demonstrated the shortest pulse width when the transmission of output mirror is 15 %. The shortest pulse width is 110ns.4. The principle of the mode locked lasers was given in this paper. By using SWCNTs as the saturable absorber, we have demonstrated a high power Nd:YVO₄ mode-locked laser. The pulse laser with pulse duration of 7.6 ps and a repetition rate of 96 MHz has been obtained. The maximum average output power is 3.6 W under the pump power of 12 W. The peak power and the single pulse energy are high to 4.9 kW and 36 nJ, respectively.更多还原