LD环状侧面均匀泵浦Nd∶YAG激光振荡器

LD ring side-pumped Nd∶YAG laser oscillator

激光二极管(Laser Diode,LD)环状侧面均匀泵浦的激光振荡器具有结构简单、光束质量高、单脉冲能量大等特点,常常在高能脉冲固体激光器中作为主振荡功率放大(MOPA)结构的振荡器,一直是国内外科研人员研究的重要方向之一。本论文通过Zemax软件对不同激光二极管排列方式以及不同工作物质吸收系数对吸收光场的影响的进行了仿真。基于仿真结果,设计了一种20个bar条串联的环状侧面泵浦结构,以提高晶体吸收的均匀性。通过该环状侧泵结构,结合超高斯非稳腔设计,搭建了一种双棒串接激光振荡器进行实验研究。该振荡器实现了在100 Hz重复频率下,单脉冲能量为496 mJ、脉冲宽度为12.4 ns的1064 nm激光输出,光束质量优于9 mm·mrad,光-光转换效率为18.5%。并且该振荡器可以维持光轴稳定不变的同时,实现20 ns脉宽以内变档可调。实验结果证明了该环状侧面均匀泵浦结构可靠有效,为MOPA结构振荡器选取提供了一种有效的方案。

The laser diode(LD)ring uniformly side-pumped laser oscillator has the characteristics of simple structure,high beam quality and large single pulse energy,etc and it is often used as the oscillator stage of main oscillation power amplification(MOPA)structure of the oscillator in high-energy pulsed solid-state lasers,which is an important direction of the domestic and foreign researchers′research.In this paper,the influence of different arrangement of laser diodes and different absorption coefficients of working materials on the absorbed light field is simulated by Zemax software.Based on the simulation results,a ring side-pumped structure with 20 bar strips in series is designed to improve the uniformity of crystal absorption.Through the ring side-pumped structure,with the unstable resonator design,a laser oscillator is built for experimental study.A 1064 nm laser with a single pulse energy of 496mJ and a pulse width of 12.4 ns is achieved at a repetition rate of 100 Hz,with a beam quality better than 9mm·mrad and an optical-optical conversion efficiency of 18.5%.Moreover,the oscillator can maintain the stability of optical axis at the same time,to realize 20 ns pulse width the within variable gear adjustable.The experimental results show that the ring side-pumped structure is reliable and effective,which provides an effective scheme for selecting the oscillation stage of MOPA structure.