传导冷却结构紧凑型高峰值功率纳秒级激光器

Conduction Cooling and Compact,High Peak-Power,Nanoseconds Pluse Lasers

报道了一种基于被动调Q Nd∶YAG微片结构的主振荡功率放大和Nd∶YVO4板条多程放大的激光器。主振荡级采用Nd∶YAG/Cr4＋∶YAG被动调Q微片激光器,在重复频率为1 k Hz时,输出单脉冲能量为82μJ、脉冲宽度为1 ns的近衍射极限的激光输出。为了实现信号光在Nd∶YVO4中获得5次放大,设计采用了多程往返光路。得到最大单脉冲能量为2.3 m J,脉宽为1 ns的激光输出,峰值功率大于2 MW,光束质量M2因子为M2x=2.48和M2y=1.24。该激光器结构简单、紧凑,采用传导冷却进行散热,适用于空间激光,在15℃~32℃的范围内,输出能量波动小于4%。

A master oscillator power amplifier（MOPA） structure based on Nd∶YAG microchip and Nd∶YVO4slab is reported. The master oscillator is a passive Q-switched Nd∶YAG/Cr4＋∶YAG microchip laser, and the seed laser with pulse energy of 82 m J and pulse width of 1ns is obtained when the repetition frequency is 1 k Hz. In the amplifier,an output pulse energy of 2.3 m J with peak powers reaching 2 MW and pulse width of 1ns is obtained while the oscillator provides the amplifier with a 82 m J input. Meanwhile, the M2 factor of beam quality is measured to be 2.48 at x direction and 1.24 at y direction. This laser systerm is compact and air-cooled, the fluctuation of output energy is below 4% when the temperature ranges from 15 ℃ to 32 ℃。