报道了一种新型纳秒脉冲532 nm绿光激光器,其基频光为耗散孤子共振(DSR)方波纳秒脉冲、由掺镱光纤激光器得到,该激光器采用了全光纤主振荡功率放大(MOPA)结构设计。利用非线性偏振旋转(NPR)锁模技术,掺镱光纤激光种子源产生了稳定的DSR方波纳秒脉冲激光输出,输出激光的脉冲宽度随抽运功率的改变在3~40 ns之间可调。利用该DSR方波纳秒脉冲激光作为种子源,经过一级非保偏结构掺镱光纤纤芯放大和两级全保偏结构掺镱光纤包层放大之后,得到了平均功率为6.95 W,峰值功率为4.4 k W的脉冲激光输出。利用长度为20 mm的非线性晶体LBO作为频率转换器,得到了平均功率为2.1 W的绿光激光输出,相应的光光转换效率为30.2%。
A novel nanosecond-pulsed, frequency-doubled green laser at 532 nm is reported, whose fundamental light is a dissipative soliton resonance(DSR) square-shaped, nanosecond pulse, which is obtained by all-fiber ytterbium-doped laser with master-oscillator power-amplifier(MOPA) system. The ytterbium-doped fiber seed laser generates stable DSR, square-shaped, nanosecond pulse by using nonlinear polarization rotation(NPR) modelocked technology. The pulse width of the fiber laser can be stably turned from 3 ns to 40 ns by just changing the pump power. After one stage non polarization-maintained ytterbium-doped fiber and two stages polarizationmaintained ytterbium-doped fiber amplification, the final output power is 6.95 W, corresponding to a peak power of 4.4 k W. The output of the all-fiber MOPA is launched into a 20 mm-long LBO crystal and a maximum secondharmonic power of 2.1 W is obtained at a fundamental power of 6.95 W with the optical conversion efficiency of30.2%.