基于YAG/Nd:YAG/Cr^(4+):YAG键合晶体的被动调Q亚纳秒激光器

Passively Q-switched sub⁃nanosecond laser based on YAG/Nd:YAG/Cr^(4+):YAG composite crystal

全固态被动调Q激光器有光束质量好、脉冲宽度窄、结构紧凑等特点,在雷达探测、工业制造等领域具有广泛应用前景。对YAG/Nd:YAG/Cr^(4+):YAG键合晶体被动调Q激光器的输出特性进行了理论和实验研究,在泵浦光中心波长为808 nm、光斑直径为230μm、泵浦功率为6.72 W的泵浦条件下,获得了平均功率1.41 W、脉宽736 ps,重复频率8.46 kHz的调Q激光输出。进一步研究表明,随着泵浦光焦点远离Nd:YAG端面,激光光斑的对称性下降;且泵浦光焦点离Nd:YAG端面的距离沿晶体轴向增大时,激光阈值呈上升趋势。

Due to its excellent characteristics of good beam quality,narrow pulse width and compact structure,all-solid-state passively Q-switched lasers have a wide application in radar detection,industrial manufacturing etc.Here,the output characteristics of passively Q-switched YAG/Nd:YAG/Cr^(4+):YAG laser are studied theoretically and experimentally.While being pumped by 808 nm laser with 230μm beam diameter and 6.72 W power,a Q-switched laser output with an average power of 1.41 W and pulse width of 736 ps at the repetition rate of 8.46 kHz is obtained.Furthermore,it is shown that the symmetry of the laser beam decreases as the focus of the pump laser moves away from the Nd:YAG end face,and the laser threshold shows an upward trend when the distance between the focus of the pump laser and the Nd:YAG end face increases along the axis of the crystal.