报道了一种高效率、结构紧凑型的激光二极管(LD)侧面抽运Nd:YVO4板条激光放大器。主振荡器为被动调Q微片激光器,在重复频率为20kHz时,种子激光为平均功率为0.5W,脉冲宽度为2.371ns的基模激光。为了匹配抽运光模体积,实现高的能量提取效率和高增益放大,并减小热透镜效应,设计了一种分别对抽运光和种子激光进行整形的激光放大器。采用柱透镜对LD单bar发射的抽运光进行整形,同时采用焦距为75mm的球透镜组对一通放大种子激光进行压缩;采用焦距为60mm的柱透镜组对二通和三通放大种子激光进行压缩,以匹配抽运光的模体积。在重复频率为20kHz时,实现了平均功率为5.5W,脉冲宽度为2.5ns,光束质量因子M2为1.5的激光输出,能量提取效率大于14%。 A highly efficient, compact laser diode (LD) side-pumped Nd: YVO4 slab laser amplifier is reported. The main oscillator is a passive Q-switched Q-switched laser. When the repetition rate is 20kHz, the seed laser is a fundamental mode laser with an average power of 0.5W and a pulse width of 2.371ns. In order to match the volume of pumping optics, to achieve high energy extraction efficiency and high gain amplification, and to reduce the thermal lens effect, a laser amplifier was designed to reshape the pump light and the seed laser, respectively. A cylindrical lens is used to shape the pump light emitted by a single bar LD while compressing a large-aperture laser with a spherical lens group with a focal length of 75 mm. A two-way and three-way magnifying seed laser are compressed by a cylindrical lens group with a focal length of 60 mm Compressed to match the volume of the pumped light. When the repetition frequency is 20kHz, the laser output with the average power of 5.5W, the pulse width of 2.5ns and the beam quality factor M2 of 1.5 is achieved, and the energy extraction efficiency is more than 14%.