半导体激光泵浦的高功率锁模激光器研究

发布时间：2018-05-09 03:09

本文选题：LD泵浦 + 锁模激光器　；参考：《上海交通大学》2015年硕士论文

【摘要】：使用半导体激光二极管(LD)泵浦的全固态激光器,有着高效率、高稳定性、结构紧凑以及光束质量好等优点,在科学研究、工业加工、激光医疗以及军事探测打击方面都有着广泛的应用,在现今的激光发展研究中是一个很重要的领域。尤其是高功率的超短脉冲锁模激光器,在各个领域内都有很重要的应用,对各种不同激光晶体锁模特性的研究成了激光研究中很重要的方面。本论文中,我们利用LD(阵列)进行泵浦,针对可得到近红外激光的两种晶体,Nd:YVO4晶体和Yb:LuAG晶体的激光输出性能进行了研究。本文主要内容可以分为五个部分:①全固态激光器以及全固态锁模激光器的背景和发展现状,包括第一章②锁模技术的基本原理以及半导体饱和吸收镜SESAM的原理,包括第二章③基于Yb:Lu AG晶体的双波长锁模激光器,包括第三章④LD泵浦高功率Nd:YVO4锁模激光器的实验研究,包括第四章⑤工作总结以及展望,包括第五章在第一部分,我们从激光器的发明开始,介绍了1960年以来全固态激光器的发展过程及现状。主要介绍了固体激光器的泵浦方式从灯泵向半导体激光泵浦的转变,以及在研究超快锁模激光器的过程中各种不同锁模技术的进步变化。在第二部分,我们介绍了锁模的基本原理,并对常用锁模器件SESAM进行了简介。主要从公式上推导了锁模技术为何能够通过锁定纵模相位来生成超短脉冲,并从SESAM的特性上分析了其如何在激光腔内起到锁模的作用。在第三部分,我们在实验室中实现了Yb:LuAG激光器的波长脉宽可切换的锁模运转。使用掺杂浓度10%,通光长度3mm的Yb:LuAG晶体,实现了波长以及脉宽可稳定切换的锁模激光输出。通过对狭缝进行调节,激光器可以分别得到中心波长为1031nm,脉冲宽度1.15ps的皮秒脉冲输出或中心波长1046nm,脉冲宽度252fs的的飞秒脉冲输出,最高输出功率达到2.2W。不同的皮秒或飞秒脉冲可以作为可切换泵浦源在泵浦OPO时产生重要作用。在第四部分,我们基于热键合的Nd:YVO4激光晶体,在单谐振腔中获得锁模脉冲输出,得到国内最高的47.5W平均功率输出。在该工作中,我们采用中心波长888nm的泵浦源以及热键合Nd:YVO4晶体降低晶体工作时的热负载。理论上,利用有限元软件ANSYS分析了热键合Nd:YVO4晶体在高功率泵浦下的温度分布以及热透镜效应;实验上,采用100W的光纤耦合888nm泵浦源,以及长度为(5+30+5)mm的热键合YVO4-Nd:YVO4-YVO4晶体,在单谐振腔内获得了中心波长1064nm,最高平均功率47.5W的锁模脉冲输出。在第五部分,我们对本文涉及的工作做了总结与展望。在论文中,我们所研制的Yb:LuAG激光器具有高功率以及波长脉宽可切换等特点,可以用作泵浦光学参量振荡器来得到宽带调谐的中红外脉冲;Nd:YVO4振荡器有着国内最高的平均功率输出,由于其皮秒高功率的特点,可以在工业上应用于硅片冷加工等,此外,在实验室中也可以泵浦光学参量振荡器尝试得到10W量级的脉冲,这些应用也会是我们将来的研究方向。
[Abstract]:All solid-state laser pumped by semiconductor laser diode (LD) has many advantages, such as high efficiency, high stability, compact structure and good beam quality. It is widely used in scientific research, industrial processing, laser medical treatment and military detection attack. It is a very important field in the current research of laser development. It is a high power ultrashort pulse mode locked laser, which is very important in all fields. The study of the mode locking characteristics of various different laser crystals has become an important aspect of laser research. In this paper, we use LD (array) to pump two kinds of crystals, Nd:YVO4 crystals and Yb:LuAG crystals that can be obtained by near red laser. The laser output performance is studied. The main contents of this paper can be divided into five parts: (1) the background and development status of all solid state laser and all solid state mode locked laser, including the basic principle of the first chapter, and the principle of the semiconductor saturable absorption mirror SESAM, including second chapters (3) the dual wavelength lock based on the AG crystal. The mode laser, including the experimental research of third chapter 4 LD pumped high power Nd:YVO4 mode locked lasers, includes fourth chapters 5 work summing up and prospect, including the fifth chapter in the first part. From the beginning of the laser, we introduce the development and status of the solid-state laser since 1960. It mainly introduces the pump of solid state laser. In the second part, we introduce the basic principle of the mode locking, and introduce the common mode locking device SESAM. The main reason is to deduce the reason that the mode locking technology can be locked through the lock. The longitudinal mode phase is used to generate the ultrashort pulse, and the function of how to lock the mode in the laser cavity is analyzed from the characteristics of SESAM. In the third part, we have realized the switching mode operation of the wavelength pulse width of the Yb:LuAG laser in the laboratory. The wavelength and the pulse width can be realized by using the Yb:LuAG crystal with the doping concentration of 3mm and the light length of the laser. A stable switched mode locked laser output. By adjusting the slit, the laser can obtain a picosecond pulse output of a central wavelength of 1031nm, a pulse width of 1.15ps or a central wavelength of 1046nm, a pulse width of 252fs, and the highest output power of a picosecond or femtosecond pulse with a different 2.2W. as a switchable pump. The Pu source plays an important role in pumping OPO. In the fourth part, we obtain the mode-locked pulse output in a single resonator based on the Nd:YVO4 laser crystal with hot bonding, and get the highest average power output of the domestic 47.5W. In this work, we use the central wavelength 888nm pump source and the hot bonding Nd:YVO4 crystal to reduce the crystal working time. Thermal load. In theory, the temperature distribution and thermal lens effect of hot bonding Nd:YVO4 crystal under high power pump are analyzed by the finite element software ANSYS. In the experiment, the central wavelength 1064nm in the single resonant cavity is obtained by using 100W optical fiber coupled 888nm pump source and the hot bonding YVO4-Nd:YVO4-YVO4 crystal with a length of (5+30+5) mm. In the fifth part, we have made a summary and Prospect of the work involved in this paper. In this paper, the Yb:LuAG laser we developed has the characteristics of high power and wavelength switching, which can be used as a pump optical parametric oscillator to obtain the wide-band tunable medium infrared pulse; Nd:YVO4 oscillation. The device has the highest average power output in China. Because of its high picosecond power, it can be used in silicon cold processing industry in industry. In addition, it can also pump optical parametric oscillator in the laboratory to get 10W order of pulse. These applications will also be our future research direction.

【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248

【参考文献】