高频电光调Q脉冲串固体激光及其在高速摄影中的应用研究

发布时间：2018-06-14 20:53

  本文选题：高频电光调Q + 弹光效应　； 参考：《长春理工大学》2014年博士论文

【摘要】：高速摄影在对高速运动目标的姿态、激光加工过程、化学反应过程等一些快速过程的研究起着非常重要的作用,应用前景十分广阔。在高速摄影中,对照明光源的要求很高,光源的亮度直接影响到摄影的质量。高频电光调Q激光是高速摄影中优选光源之一,本文就满足高速摄影,以Nd:YAP作为激光工作物质的激光系统开展了一系列研究。首先,在研究了Nd:YAP晶体特性、能级结构、吸收光谱、热效应等基础上,为了深入了解Nd:YAP作为工作物质激光器的特性,用图解法设计LD泵浦Nd:YAP连续运转激光器,获得了重要参数和数据。在此基础上,开展了灯泵脉冲Nd:YAP激光器理论及实验研究。设计了灯泵浦脉冲运转激光器和变换频率为100k Hz的恒流充电电源,并对影响激光输出稳定性的充电精度进行了深入的探讨。研制成功了输出脉冲能量350m J,重复频率1Hz,脉冲宽度500μs,输出波形为方波的Nd:YAP激光器。其次,在激光器研制成功的基础上,以四能级系统模型为基础,求解四能级调Q速率方程,结合泵浦条件,获得了重复频率与调Q激光器输出特性之间的关系。测出重复频率在50-150k Hz范围内的激光输出能量、建立时间、脉冲宽度的试验曲线,设计了高频电光调Q系统。由于高频调Q激光输出稳定性是一直以来最难解决的关键问题,本文对弹光效应等因素进行了深入分析,采用了有效方法来产生稳定的激光脉冲,实现了脉冲透射式(PTM)调Q,频率为150k Hz的脉冲序列。最后,在单级调Q激光器研究的基础上,为了满足高速摄影对光源功率的要求,设计了两级激光放大器,研制完成了由一级本振加两级放大的激光系统。并通过倍频的,获得了波长为0.532μm,输出能量为1J的激光输出。对激光输出能量的不稳定性进行理论与试验研究,解决各类不稳定因素,使激光输出的能量和稳定性均达到高速摄影的要求。通过对高速运动目标进行同步摄影实验,证明该高频调Q激光系统完全满足高速摄影对光源的要求。
[Abstract]:High-speed photography plays a very important role in the study of some rapid processes such as the attitude of high speed moving target, laser processing, chemical reaction and so on, and the application prospect is very broad. In high-speed photography, the requirement of lighting source is very high, the brightness of light source directly affects the quality of photography. High frequency electro-optic Q-switched laser is one of the best light sources in high speed photography. In this paper, a series of studies have been carried out on the laser system with ND: Yap as the working material for high speed photography. First of all, based on the study of ND: YAP crystal characteristics, energy level structure, absorption spectrum, thermal effect and so on, in order to deeply understand the characteristics of ND: Yap laser as working matter, LD pumped ND: Yap continuous operating laser is designed by graphic method. Important parameters and data are obtained. On this basis, the theoretical and experimental study of lamp pump pulsed ND: YAP laser is carried out. A lamp pumped pulse operating laser and a 100kHz constant current charging power supply are designed, and the charging accuracy which affects the stability of laser output is discussed. ND: YAP laser with output pulse energy 350 m J, repetition rate 1 Hz, pulse width 500 渭 s and square wave output is successfully developed. Secondly, on the basis of the successful development of the laser, based on the four-level system model, the four-level Q-switched rate equation is solved, and the relationship between the repetition rate and the output characteristics of the Q-switched laser is obtained in combination with the pump conditions. The laser output energy at the repetition rate of 50-150 kHz was measured, and the experimental curves of time and pulse width were established. A high-frequency electro-optic Q-switching system was designed. Because the stability of high frequency Q-switched laser output is the most difficult to solve, this paper makes a thorough analysis of the elasto-optical effect and adopts an effective method to produce stable laser pulse. A pulse sequence with a frequency of 150 kHz is realized. Finally, based on the research of single-stage Q-switched laser, a two-stage laser amplifier is designed to meet the requirements of high speed photography for light source power, and a laser system with one stage local vibration and two stage amplification is developed. A laser with a wavelength of 0.532 渭 m and an output energy of 1 J has been obtained by frequency doubling. The instability of laser output energy is studied theoretically and experimentally in order to solve all kinds of unstable factors and make the energy and stability of laser output meet the requirements of high-speed photography. The high frequency Q-switched laser system is proved to meet the requirements of high speed photography.
【学位授予单位】：长春理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TB86;TN248
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本文编号：2018927