提出了一种新型的高功率激光装置的预放系统结构,采用钕玻璃再生放大结合离轴四程放大的技术途径,研究了四程放大中寄生振荡和笔形光束的产生机理和抑制措施。通过注入脉宽为3ns,单脉冲能量小于1nJ的1053nm单纵模种子激光,可以获得10.3J的近衍射极限输出,总增益大于1010,能量稳定性为2%,输出激光为近平顶分布,近场填充因子为71%,近场调制度约为1.4,91%的焦斑能量能聚焦于2倍衍射极限内。实验结果和输出性能完全满足激光装置预放系统的性能要求,验证了多程放大技术在高功率激光装置预放系统中应用的可行性。 A new type of high power laser preamplifier system is proposed. The regenerative amplification of neodymium glass combined with the four way amplification of off-axis is used to study the generation mechanism and suppression of parasitic oscillation and pencil beam in four-way amplification. By injecting 1053nm single longitudinal mode seed laser with pulse duration of 3ns and single pulse energy less than 1nJ, the near-diffraction limit output of 10.3J can be obtained. The total gain is more than 1010, the energy stability is 2%, the output laser is nearly flat- The near-field fill factor is 71%, the near-field modulation is about 1.4, the focal spot energy of about 97% can be focused within 2X diffraction limit. Experimental results and output performance fully meet the performance requirements of the laser device pre-release system to verify the feasibility of multi-path amplification technology in high-power laser device pre-release system.