中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
基于LIDAR应用的全固化激光技术研究

文献类型:学位论文

作者牛林全
学位类别博士
答辩日期2013-11-20
授予单位中国科学院研究生院
授予地点北京
导师孙传东 ; 朱少岚
关键词全固化激光器 可饱和吸收体 微腔激光器 脉冲光纤激光器和放大器 MOPA
学位专业光学工程
中文摘要        激光器是激光雷达的核心,其性能指标直接决定了激光雷达的主要技术参数。基于脉冲测距体制的激光三维成像雷达是激光雷达的重要成员之一,要求激光器需具有高重复频率、窄脉冲、高光束质量、高效率和体积小、重量轻等特点。本论文针对激光三维成像雷达的应用,对半导体激光器(LD)泵浦的被动调Q微腔固体激光器和基于主振荡功率放大(MOPA)掺Yb3+脉冲光纤激光器进行了研究,并研制出MOPA脉冲光纤激光器工程样机,在激光三维成像雷达上进行了应用。
本论文的主要工作和创新结果包括以下几个方面:
  1. 基于Cr4+:YAG被动调Q速率方程,推导得出了激光脉冲输出特性相对于两个无量纲常变量z和α的函数;利用相应函数,对脉冲能量、峰值功率、脉冲宽度、激光效率等激光脉冲参数特性进行数值模拟和理论分析,为被动调Q微腔激光器的设计提供了理论指导。
  2. 搭建了LD泵浦Nd:YAG/Cr4+:YAG被动调Q微腔激光器系统,实现稳定调Q激光脉冲输出。并针对在实验研究过程中观察到的双脉冲时间波形现象进行了理论分析和实验研究,发现双脉冲时间波形与激光空间模式分布存在着对应关系,经分析得到了激光器双纵模的振荡是导致这种现象的直接原因。提出了实际应用中避免此现象的解决方案并进行了实验验证。
  3. 建立了基于MOPA结构的高峰值功率纳秒掺Yb3+全光纤激光器系统,实现1064nm脉冲宽度<1ns~10ns可调、重复频率10kHz~1MHz可调、峰值功率为123kW的稳定单横模激光脉冲输出。这种峰值功率高、可控性强、稳定性好、可靠性高的全光纤激光器系统,对激光三维成像雷达整机性能的提升有极大的促进作用。
  4. 研制出高峰值功率脉冲全光纤激光器工程样机应用于激光三维成像雷达系统,进行三维成像实验,激光三维成像雷达在40o×40o的视场范围内,成像分辨率最高可达4096×4096,距离精度达到±7.5cm,成像实验结果表明研制的激光器可满足三维成像雷达的高分辨率成像需求。同时通过激光雷达系统的长期室内和户外工作验证了激光器的可靠性和稳定性。
英文摘要Laser is the core of LIDAR, which has a great impact on the key parameters of LIDAR system. And 3D imaging LIDAR based on the pulse ranging mechanism plays an important role in the system of LIDAR, which is an active device in that it carries its own transmitter and does not depend on ambient radiation. As the transmitter of 3D imaging LIDAR, Laser must be required to some special characteristics, such as high repetition rate, narrow temporal duration, excellent beam quality, high efficiency, robust, and so on. This dissertation focuses on two kind laser technologies for the applications of 3D imaging LIDAR: a passively Q-switched microchip laser and Yb3+-doped pulse fiber amplifier based on MOPA structure. Meanwhile, the practical sample of pulsed all-fiber laser has been successful developed and applied to the 3D imaging LIDAR system.
The main research works and innovations of this dissertation are summarized as follows:
1.                   Basing on the rate equations of Cr4+:YAG passively Q-switched laser, the output characteristics of pulsed laser as a function of two dimensionless variables are derived. According to the relationships, the laser parameters including pulse energy, peak power, pulse width, and laser efficiency are acquired by means of theoretical analysis and numerical simulation. It is useful to define the laser parameters when the anticipant pulse energy.
2.                   Single- and dual-pulse oscillation delivered from a LD pumped passively Q-switched Nd:YAG/Cr4+:YAG microchip laser has been investigated under the different pump levels. And the dual-pulse waveform consists of a main pulse and a satellite pulse with respective intensities and optical spectra. Experimental results indicate that the dual-pulse emission results from double longitudinal mode oscillation. The preponderant oscillating mode gives birth to the main pulse, and the other oscillating mode corresponds to the satellite pulse.
3.                   A compact high power nanosecond all-fiber MOPA system based on Yb3+-doped fiber amplifier system is established. Laser pulse with stable wavelength, controllable repetition rate and adjustable pulse duration is obtained. And the peak power is up to 123kW. As the transmitter of 3D imaging LIDAR, it is benefit to improve the capabilities of the entire system. Temporal duration and repetition rate of the laser pulse can choose flexible according to the different practical application.
4.                   The proposed fiber amplifier is used as the laser source of three-dimension (3D) imaging LIDAR system, which achieves the function of 3D imaging and gives the scanning imaging results. The performance of the laser is verified. The imaging results show that the proposed fiber amplifiers with high peak power have the excellent reliability and stability and are very suitable for 3D imaging LIDAR system. The imaging resolution is 4096×4096, the field of view is 40o×40o, and the ranging accuracy is about ±7.5cm
学科主题激光器 ; 激光的应用
语种中文
公开日期2014-04-18
源URL[http://ir.opt.ac.cn/handle/181661/21048]  
专题西安光学精密机械研究所_研究生部
推荐引用方式
GB/T 7714
牛林全. 基于LIDAR应用的全固化激光技术研究[D]. 北京. 中国科学院研究生院. 2013.

入库方式: OAI收割

来源:西安光学精密机械研究所

浏览0
下载0
收藏0
其他版本

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。