3.2ns高峰值功率YAG/Nd∶YAG/Cr^(4+)∶YAG键合晶体被动调Q径向偏振微片激光器

3.2 ns High Peak Power Radially Polarized Pulsed Output from Passively Q-Switched Microchip Laser with Composite Structure of YAG/Nd∶YAG/Cr^(4+)∶YAG Crystal

实验利用YAG/Nd∶YAG/Cr4+∶YAG键合晶体和光子晶体光栅镜获得高峰值功率和高光束质量的被动调Q径向脉冲激光输出,激光器的输出功率达到435 m W,斜率效率为14.7%。在吸收抽运功率为6.8 W时,输出激光脉冲的峰值功率达到15.7 k W,脉冲能量达到50.1 m J,脉冲宽度为3.2 ns,重复频率为8.1 k Hz,径向偏振纯度为95.8%。实验中的晶体均采用<111>的切割方向,输出径向偏振光束的均匀性得到提高。

High peak power radially polarized laser pulse is obtained from a passively Q-switched microchip laser with composite structure of YAG/Nd∶YAG/Cr^4＋∶YAG crystal and photonic crystal grating mirror as the polarization-selective output coupler. The average output power is 435 Mw and a slope efficiency is 15.7%. The laser pulse output has a maximum peak power of 15.7 kW, a minimum pulse duration of 3.2 ns, and repetition rate of 8.1 k Hz at absorbed pump power of 6.5 W. The polarization degree of the radially polarized pulse is measured to be as high as 95.8%. All of the crystals in the experiment are 111 cut which is more beneficial for this laser to improve the uniformity of output radially polarized beam.