新型稀土掺杂光纤放大器的研究

发布时间：2018-03-30 19:21

本文选题：啁啾脉冲放大　切入点：全光纤结构　出处：《华东师范大学》2015年硕士论文

【摘要】：超短激光放大器是激光领域一个重要的研究方向,特别是基于稀土掺杂离子的超短光纤放大器,有着体积小、结构紧凑、泵浦效率高、散热性好等等优点。尤其是工作在1.5μm波段的掺铒光纤放大器,有着人眼安全的特点,在科学研究中广泛应用于高功率产生、太赫兹生成、精密光谱控制等方面,在激光雷达、激光测距、遥感、环境检测、高精度检测、医疗设备等方面得到了广泛的应用和研究。此外,经过简单的倍频,高功率超短脉冲掺铒光纤激光系统可以将输出波长扩展到800nm附近,利用传统的钛宝石激光系统的成熟器件,实现对输出激光的精密操控。本论文主要研究成果如下：1.基于一种新型的放大技术——分离脉冲放大技术,实现了一个高功率的掺铒光纤激光器。利用45。角切割的钒酸钇晶体组设计了一种新型的方案,使不同偏振态的脉冲在空间上进行分离,有效减小不同偏振态脉冲之间的非线性耦合。在实验上验证了脉冲分离的过程,获得了平均功率为2W的高功率脉冲输出。利用4.5m长的单模光纤对放大后的平均功率为650mW脉冲进行了压缩,再用一块周期极化铌酸锂晶体对其进行倍频,获得了平均功率为110mW的780nm激光脉冲,脉冲的宽度为95.7fs。2.基于啁啾脉冲放大技术,研制了全光纤结构的超短脉冲放大系统。采用非线性旋转锁模技术,搭建了光纤振荡器。分别使用了单模掺铒光纤以及铒镱共掺的增益光纤来对脉冲进行预放大和主放大,使用色散补偿光纤实现了脉冲的展宽,使用普通单模光纤对脉冲进行压缩。通过在脉冲展宽和压缩过程中改变色散光纤的插入量对光谱畸变进行了有效的控制,获得了最高功率为1.81W,脉冲宽度为420fs的超短脉冲输出。最后利用周期极化的铌酸锂晶体对放大激光脉冲进行倍频,将激光波长拓展到近红外的780nm附近,光谱宽度达到llnm。
[Abstract]:Ultrashort laser amplifiers are an important research field in laser field, especially the ultrashort fiber amplifiers based on rare earth doped ions have small size, compact structure and high pump efficiency. Especially the erbium-doped fiber amplifier which works at 1.5 渭 m band has the characteristics of human eye safety. It is widely used in high power generation, terahertz generation, precision spectrum control and so on in the field of laser radar, in scientific research, especially in the fields of high power generation, terahertz generation, precision spectrum control and so on. Laser ranging, remote sensing, environmental detection, high precision detection, medical equipment and other fields have been widely used and studied. In addition, after a simple frequency doubling, The high power ultrashort pulse erbium-doped fiber laser system can extend the output wavelength to the vicinity of 800nm, using the mature devices of the traditional Ti: sapphire laser system. The main results of this thesis are as follows: 1. Based on a new amplification technology, the separation pulse amplification technology, A high power erbium-doped fiber laser is realized. A new scheme is designed by using 45. angle-cut yttrium vanadate crystal set to separate pulses with different polarization states in space. The nonlinear coupling between pulses with different polarization states is reduced effectively. The process of pulse separation is verified experimentally. A high power pulse output with an average power of 2W is obtained. The amplified average power 650mW pulse is compressed by a 4.5m long single-mode fiber, and then a periodically polarized lithium niobate crystal is used to double the frequency of the pulse. 780nm laser pulse with average power of 110mW is obtained, the pulse width is 95.7fs.2. based on chirped pulse amplification technology, an ultrashort pulse amplification system with all-fiber structure is developed. The nonlinear rotation mode-locking technique is used. The single-mode erbium-doped fiber and erbium-ytterbium co-doped gain fiber are used to preamplify and master amplify the pulse, and dispersion compensation fiber is used to widen the pulse. The pulse is compressed by ordinary single-mode fiber. The spectral distortion is effectively controlled by changing the insertion of dispersive fiber during pulse broadening and compression. An ultrashort pulse with a maximum power of 1.81 W and a pulse width of 420fs is obtained. Finally, the frequency doubling of the amplified laser pulse is carried out by using the periodically polarized lithium niobate crystal. The wavelength of the laser is extended to near the near infrared 780nm, and the spectral width is up to llnm.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN722

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