Huang Chunning, Deibele Craig, Liu Yun
Spallation Neutron Source, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA.
Opt Express. 2013 Apr 8;21(7):9123-31. doi: 10.1364/OE.21.009123.
We demonstrate a master oscillator power amplifier (MOPA) burst mode laser system that generates 66 ps/402.5 MHz pulses with mega-watt peak power at 355 nm. The seed laser consists of a single frequency fiber laser (linewidth < 5 KHz), a high bandwidth electro-optic modulator (EOM), a picosecond pulse generator, and a fiber based preamplifier. A very high extinction ratio (45 dB) has been achieved by using an adaptive bias control of the EOM. The multi-stage Nd:YAG amplifier system allows a uniformly temporal shaping of the macropulse with a tunable pulse duration. The light output from the amplifier is converted to 355 nm, and over 1 MW peak power is obtained when the laser is operating in a 5-μs/10-Hz macropulse mode. The laser output has a transform-limited spectrum with a very narrow linewidth of individual longitudinal modes. The immediate application of the laser system is the laser-assisted hydrogen ion beam stripping for the Spallation Neutron Source (SNS).
我们展示了一种主振荡功率放大器（MOPA）脉冲模式激光系统，该系统在355nm波长处产生脉宽为66ps、重复频率为402.5MHz、峰值功率达兆瓦级的脉冲。种子激光器由单频光纤激光器（线宽<5kHz）、高带宽电光调制器（EOM）、皮秒脉冲发生器和光纤前置放大器组成。通过对EOM采用自适应偏置控制，实现了非常高的消光比（45dB）。多级Nd:YAG放大器系统能够对大脉冲进行均匀的时间整形，脉冲持续时间可调。放大器输出的光被转换到355nm，当激光器以5μs/10Hz的大脉冲模式运行时，可获得超过1MW的峰值功率。激光输出具有变换极限光谱，各个纵模的线宽非常窄。该激光系统的直接应用是用于散裂中子源（SNS）的激光辅助氢离子束剥离。
