侧面抽运国产Nd∶YAG陶瓷棒的激光特性

实验研究了激光二极管阵列(LDA)侧向抽运国产Nd∶YAG陶瓷棒的准连续及被动调Q激光输出特性。该陶瓷激光器采用LDA侧面紧密环绕均匀排布的抽运结构,陶瓷棒抽运区域长度为20 mm,其总尺寸为3 mm×35 mm,掺杂原子数分数为~1%。在千赫兹准连续运转条件下,当平-平谐振腔的输出耦合镜透过率为47.3%时,获得最大平均功率23 W的1064 nm激光输出,光束发散角为4.5 mrad,斜率效率达12%。在谐振腔内插入Cr4+∶YAG晶体作为被动调Q开关,成功地实现了陶瓷激光器千赫兹重复频率调Q激光脉冲输出,当Cr4+∶YAG晶体初始透过率为60%时,输出激光脉冲宽度(半峰全宽)可窄至14.5 ns,调Q动静比约为40%。

The quasi-continuous-wave and passively Q-switched output performance of laser-diode-array (LDA)-side-pumped domestic Nd:YAG ceramic laser were studied. A uniformly side-around arranged compact LDA pumping structure with pumping length of 20 mm was used in this laser. The Nd:YAG ceramic rod was φ3 mm×35 mm sized and 1% (atomic percent) doped. In a plano-plano concave resonator, with the working frequency of 1 kHz, and the output coupler transmission of 47.3%, a quasi-continuous-wave output with an average power of about 23 W at 1064 nm is obtained. The beam divergence angle is 4.5 mrad, and the slope efficiency is up to 12%. In the same condition, using Cr⁴⁺:YAG crystal as the passive Q-switcher, the 1 kHz Q-switched laser pulse is obtained successfully, when the original transmission ratio of Cr⁴⁺:YAG crystal is 60%, the pulse width (FWHM) is less than 14.5 ns, and the dynamic to static ratio is about 40%.