脉冲式半导体激光器端面抽运主振荡-功率放大器及腔外倍频系统

Pulsed Semiconductor Laser End-Pumped Master Oscillator Power Amplifier and External-Cavity Frequency Doubling System

利用脉冲式半导体激光器(LD)具有高峰值功率的优点,通过对抽运光和基频光的模式进行匹配,构建了一台脉冲式LD抽运腔倒空结构的主振荡器和功率放大器,并对其进行了腔外倍频实验。实验结果表明,系统实现了非常紧凑的结构,脉冲式LD抽运的方式能够提高振荡器和功率放大级的能量输出,更好地消除热畸变的影响,从振荡器可以获得脉冲宽度达3.7 ns、脉冲能量约为4 mJ的基频激光脉冲输出,经功率放大和腔外倍频后,能够得到脉宽3.4 ns、脉冲能量为3.2 mJ的绿光输出,倍频效率为40%,脉冲峰值稳定性为5%(均方根值),发散角约为0.5 mrad。

By using the advantage of pulsed semiconductor lasers with high peak power, a pulsed LD-pumped cavitydumped oscillator and power amplifier is built, and the pump light and signal light of the system are matched. In addition, external cavity second harmonic experiments are also carried out. The results show that, the pulsed LD pumping system has a very compact structure, it can increase the energy output in oscillator and amplification stage oscillator, and can better eliminate thermal distortion effects. Pulse width of 3.7 ns and laser pulse energy of 4 mJ can be obtained in the stage of the oscillator. Through the power amplifier and the second harmonic generation （SHG）, the second harmonic light with the pulse width of 3.4 ns, pulse energy of 3.2 mJ, SHG efficiency of 40 %, pulse peak stability of 5 % （root mean square） and divergence angle of 0.5 mrad is obtained.