用于激光聚变驱动器的全光纤、全固化光脉冲产生系统

Integrated all fiber optical pulse generation system for laser fusion driver

报道一种全固化、全光纤的用于高功率激光驱动的惯性约束聚变驱动器的光脉冲产生系统,采用单纵模振荡器输出连续激光信号,经过相位调制器和振幅调制器,得到一个时间波形上已整形且具有一定带宽(约0.1nm)的激光脉冲,经光纤放大器放大并经光纤分束器分束后同时输出四路激光脉冲,各路激光脉冲先通过时间同步调整单元精确控制时间同步关系后,经可编程光纤衰减器调节各路之间的功率平衡后再通过光纤放大器做进一步放大并通过150m光纤传输输出至预放系统.该光纤系统可输出0.3—20ns、带宽0.1nm、能量数纳焦的几乎任意整形的激光脉冲,并已作为神光Ⅲ原型激光装置的前端系统成功发射近260余万发次.该系统结构紧凑,具有很高的稳定性和可靠性.

We demonstrate an integrated all fiber optical pulse generation system for laser fusion driver. CW laser signal generated from a single longitudinal fiber oscillator was modulated by phase modulator and amplitude modulator to form an optical pulse with shaped waveform and bandwidth of 0.1 nm. The pulse was amplified and split by fiber multiplexer to four pulses. Time delay of each pulse was controlled by synchronization unit and power of each pulse was adjusted by programmable variable optical attenuator. The four pulses were amplified and then transmitted through a 150 m fiber to the pre-amplify system. The fiber system can generate almost arbitrarily shaped optical pulse with duration of 0.2--20 ns, bandwidth of 0.1 nm and power of several nJ. As the front-end of the SG- Ⅲ prototype facility, it has successfully lunched about 2.6 million shots of pulses. The fiber system is compact and highly stable and reliable.