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题名	种子注入单频1.57μm脉冲全固态激光器技术研究
作者	李世光
学位类别	博士
答辩日期	2013
授予单位	中国科学院上海光学精密机械研究所
导师	陈卫标
关键词	差分吸收雷达 光学参量振荡器 单频 种子注入 光谱纯度
其他题名	Research on Injection Seeded Single Frequency 1.57μm Pulsed All Solid-state Laser
中文摘要	主动探测大气CO2浓度的差分吸收雷达（DIAL）在近年来得到了广泛地研制，该系统对激光发射源要求很高，不仅要在一定能量上输出单纵模、窄线宽脉冲，还要求具有高频率稳定性。根据发展探测CO2浓度的空基DIAL需求，本论文对种子注入单频纳秒脉冲1.57 μm全固态激光器进行了研究。 论文包括探测CO2的DIAL概述，OPO基本原理及仿真，线性、环形腔OPO实验，和双脉冲OPO实验四个方面的内容。 针对应用需求，对各种材料的优缺点进行分析，最终选择KTA晶体作为获得1.57 μm输出的非线性材料。推导了光学参量放大增益的接收带宽和输出带宽的表达式，并研究了腔长抖动对输出波长的影响；探索了KTA OPO中，泵浦光线宽、晶体温度控制灵敏度对输出线宽的影响。对种子注入OPO的动态特性分析，并进行理论仿真，并指出影响OPO输出频率的各种因素。 自行研制了250 Hz的单频1.06 μm脉冲激光振荡-放大器，在输出单脉冲能量为800 mJ时，具有良好的脉冲保真度和稳定的单频运转，15 min内输出频率抖动为23.8 MHz。根据需要，实现了100 Hz脉冲重复频率输出，并将其作为KTP/KTA OPO泵浦源开展实验。环形稳定腔KTP OPO较临界腔结构，能量转换效率提高了1.8倍；获得最高单脉冲能量为3.1 mJ，对应的转换效率为18.1%，斜效率高达37.7%，脉冲宽度为6.9 ns。 国内首次报道了种子注入脉冲KTA OPO实验，分析了自由运转和种子注入的区别，测量了种子注入接收带宽，分析影响输出频率稳定性的因素，并从被动、主动两个方面，介绍获得更高频率稳定性OPO输出的研制过程。主动稳频时，4 min内，频率抖动为4.21 MHz（RMS），信号光的最大输出单脉冲能量为1.82 mW，转换效率为19.1%，输出脉冲宽度为6.9 ns，相应的线宽为65.5 MHz，接近傅里叶转换极限。 采用双脉冲泵浦源，国内首次实现了种子注入单频双脉冲KTA OPO。脉冲重复频率均为50 Hz，两个脉冲的能量分别为1.7和1.3 mJ，转换效率分别为17.8%和13.6%。脉冲宽度为13 ns，线宽为40 MHz，并提出获得双脉冲能量的一致性的方案。在对其输出的光谱纯度特性分析之后，发现输出频率稳定性的要求更高，并提出改善频率稳定性的改进方案。
英文摘要	The differential absorption lidar (DIAL) has been paid attention to actively remote sensing the concentrations of earth’s carbon dioxide in the past few years. The performance of laser transmitter for DIAL is quite high, such as single frequency, narrow linewidth, and so on. Not only high single pulse energy but also high frequency stability is required. According to the developing of spaceborne DIAL for CO2 concentration detection, the injection seeded single frequency all solid-state laser is studied with nanosecond pulse emiting at 1.57 μm wavelength in this dissertation. This dissertation is consist of four chapters, including the overview of DIAL for CO2 detection, the fundamental theory and numerical simulation of OPO’s specification, the experiments of linear and ring OPO cavity, douple-pulsed OPO, and etc. The properties of different nonliear crystals are discussed, and KTA is the selected to use in OPO to output 1.57 μm according to the DIAL’s application condition. The acceptable and lasing bandwidth of optical parametric gain is mathematically deduced, as well as the influence of cavity length fluctuations on output wavelength. With respect to KTA OPO, the linewidth characters are studied under considering the crystal temperature controlling sensitivity and the linewidth of pumping laser. The dynamics of injection tuning of OPO are analyzed and numerically simulated, and the aspects affecting the output linewidth are pointed out. A single-frequency Nd:YAG master oscillator power amplifier at 1064 nm is successfully investigated with maximum output single pulse energy of 800 mJ at pulse repetition rate of 250 Hz and 100 Hz. The stable single-frequency operation is achieved with good temporal fidelity after amplification, and the frequency fluctuation of 23.8 MHz is obtained over 15 min. In this dissertation, the laser with the repetition rate of 100 Hz is used to pump KTP/KTA OPO. Energy conversion efficiency of 18.1% is obtained with stable ring cavity, and it is 1.8 times that of critical ring cavity approximately. The highest slope efficiency of 37.76% and maximum signal pulse energy of 3.1 mJ are attained with the output pulse width of 6.9 ns. An injection-seeded nanosecond pulse KTA OPO is developed. The differences of OPO output with and without injecton seeding are compared, and the seeding acceptable bandwidth is also measured. Then both active and passive frequency stabilization techniques are implemented to achieve high frequency stability. The frequency jitter of 4.21 MHz (RMS) is obtained over 4 min. The maximum signal pulse energy of 1.82 mJ and the energy conversion efficiency of 19.1% are attained with pulse width of 6.9 ns, as well the linewidth of 65.5 MHz. Incorporating KTA crystals and injection seeding, a single frequency double-pulse OPO is presented with home-made pump source. Pulse energy of 1.7 mJ and 1.3 mJ are obtained for the 1st and 2nd pulse at the repetition rate of 50 Hz at the maximum pump energy of 9.5 mJ. The energy conversion efficiency is 17.8% and 13.6%, respectively. The doubl pulse width is about 13 ns with a transform-limited linewidth of approximate 40 MHz. And the energy balance between the 1st and 2nd pulse is proposed. Finally, the spectral purity is discussed. The further method is put forward to improve the frequency stability.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/15736]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	李世光. 种子注入单频1.57μm脉冲全固态激光器技术研究[D]. 中国科学院上海光学精密机械研究所. 2013.

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