全固态1.3μm自锁模激光器

发布时间：2018-01-06 10:23

本文关键词：全固态1.3μm自锁模激光器　出处：《北京交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：皮秒脉冲在非线性频率变换、工业加工、光谱学、光生物学、医疗诊断等领域都有着非常广泛的应用,自锁模作为一种实现皮秒脉冲输出的新型的技术手段,目前已经成为国内外研究的热点。它具有装置简单、抗损伤阈值高、成本低、可靠性高、波长范围广、脉宽窄等优点。在皮秒自锁模领域,目前主要集中于1.0μm波段的研究,1.3μm波段研究的比较少。但是1.3μm波段脉冲激光器在光谱学、光纤通信、红外光学参量振荡等领域都有着重要的应用。其倍频红光更广泛用于光生物学和光医学领域,特别是荧光的观测和成像领域。因此,本文就1.3μm皮秒自锁模脉冲激光器展开研究。本文分别采用Nd:YV04和Nd:GdV04作为增益介质,利用激光介质的三阶非线性效应结合增益光阑形成类可饱和吸收体,实现1.3μm连续锁模皮秒激光输出。全文具体的内容如下:第一、介绍了添加脉冲锁模、半导体可饱和吸收体反射镜锁模、自锁模三种连续锁模技术及其发展概况,阐述了 1.3μm脉冲激光器的研究意义及其发展情况。第二、研究了自锁模无像差理论,并根据克尔效应原理,对软硬光阑的脉冲压缩机制予以阐述。在此基础上探究了有效非线性变量对于锁模的自启动及稳定输出的影响。第三、实验采用Nd:YVO4作为激光晶体,研究了不同腔型的1342nm皮秒锁模激光输出。在此基础上,通过对比不同泵浦光斑下的锁模波形,研究了泵浦模式与激光模式的比例对锁模脉冲输出的影响。当泵浦功率为10W时,输出脉冲的平均功率可以达到1.34W,相应的光光转换效率以及斜效率分别13.4%,17.5%。其重复频率为1.48GHz,单脉冲能量约为0.91nJ。第四、在研究Nd:GdV04热效应及有效非线性变量的基础上,首次实现了1341nmNd:GdVO4瓦级皮秒自锁模激光器的运转,同时探究了有效性非线性变量对于连续锁模稳定性的影响。其光光转换效率以及斜效率可达到16.7%、19.2%,重复频率为2.0GHz,脉冲宽度可达到9.1ps,单脉冲能量约为1.26nJ,峰值功率约为 137.9W。
[Abstract]:Picosecond pulse is widely used in the fields of nonlinear frequency conversion, industrial processing, spectroscopy, photobiology, medical diagnosis and so on. Self-mode-locking is a new technique to realize picosecond pulse output. It has many advantages such as simple device, high damage threshold, low cost, high reliability, wide wavelength range, narrow pulse width and so on. It is in the field of picosecond self-mode-locking. At present, the research focused on 1.0 渭 m band is less than 1.3 渭 m band, but 1.3 渭 m band pulse laser is in spectroscopy, optical fiber communication. Infrared optical parametric oscillation and other fields have important applications. Its frequency-doubling red light is more widely used in the field of photobiology and photomedicine, especially in the field of fluorescence observation and imaging. In this paper, a 1.3 渭 m picosecond self-mode-locked pulse laser is studied. Nd:YV04 and Nd:GdV04 are used as gain medium respectively. Using the third-order nonlinear effect of laser medium and gain aperture to form a saturable absorber, 1.3 渭 m continuous mode-locked picosecond laser output is realized. The main contents are as follows: 1. Three kinds of continuous mode-locking techniques, such as pulse mode-locking, semiconductor saturable absorber mirror mode-locking and self-mode-locking, are introduced. The significance and development of 1.3 渭 m pulsed laser are described. Secondly, the theory of self-mode-locked aberration is studied, and the Kerr effect principle is used. The pulse compressor system with soft and hard apertures is described. On this basis, the effect of effective nonlinear variables on the self-starting and stable output of mode-locking is explored. Thirdly, Nd:YVO4 is used as laser crystal in the experiment. The output of 1342 nm picosecond mode-locked laser with different cavity types is studied. On this basis, the mode-locked waveforms under different pump spot are compared. The effect of the ratio of pump mode to laser mode on the output of mode-locked pulse is studied. When the pump power is 10 W, the average power of output pulse can reach 1.34 W. The corresponding optical conversion efficiency and oblique efficiency are 13.4and 17.5.The repetition rate is 1.48GHz, and the single pulse energy is about 0.91nJ. 4th. Based on the study of Nd:GdV04 thermal effect and effective nonlinear variables, the operation of 1341 nm ND: GdVO4 picosecond self-mode-locked laser is realized for the first time. At the same time, the effect of effective nonlinear variables on the stability of continuous mode-locking is investigated. The optical and optical conversion efficiency and skew efficiency can reach 16.7GHz and 19.2GHz, and the repetition rate is 2.0GHz. The pulse width can reach 9.1 ps.Monopulse energy is about 1.26 nJ, and the peak power is about 137.9 W.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN248

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