研究了一种用于惯性约束聚变激光驱动器的纳秒级、高精度整形激光脉冲产生技术。采用中心波长为 980 nm 的激光二极管作为参考光,以自动调控幅度调制器的偏置工作点,实现了脉冲工作体制的幅度调制。基于高速电光调制技术,采用两级幅度调制器设计了主振荡功率放大型全光纤激光脉冲产生装置。其中,第 1 级幅度调制器用于对输入连续运转的单纵模激光进行初始精密脉冲整形,第 2 级幅度调制器用于对激光脉冲进行二次精密整形和时域噪声抑制。实验研究表明,该激光脉冲产生装置可输出脉冲宽度在“0.1~50.0 ns”范围内连续可调、对比度大于 2000∶1 的高精度任意整形激光脉冲,满足了激光脉冲产生装置脉冲较强控制能力的要求。
The nanosecond-scale laser pulse generation technology with high adjustment precision for laser fusion driver is investigated. By employing a laser diode with central wavelength of 980 nm as reference light and controlling the bias point automatically, an amplitude modulator operating in the pulse mode is implemented. All- fiber laser pulse generation device based on the master oscillator power amplifier structure is established by using high speed electro-optic modulation technology and two-level amplitude modulators simultaneously. The initial precise pulse shaping of input single frequency continuous laser is done by the first amplitude modulator, and the secondary pulse shaping and decreasing noise of temporal shaped pulses are done by the other one. The experimental results show that the device can generate arbitrary shaped pulses with contrast ratio larger than 2000:1 and pulse duration of 0.1~ 50.0 ns, which satisfies the requirement of powerful control capability of laser pulse generation device.