大型激光装置脉冲波形调控技术

Autonomous pulse shaping method for high-power laser facility

精密高效的脉冲波形调控是大型激光装置满足惯性约束聚变实验需求的重要技术之一。脉冲波形生成原理是通过编辑任意波形发生器中每个子脉冲的电压值,经电光调制器转换为光脉冲强度形成任意形状的激光脉冲轮廓。在电光转换过程中,各子束响应过程并非线性且子束间存在个性差异。为实现此条件下精密高效的脉冲波形调控,制定并开发了基于闭环迭代思路的激光脉冲波形快速调控方法。实验结果表明,算法可在10 min内实现任意脉冲波形整形,并具备23∶1高对比度脉冲波形调控能力,调控精度均优于10%(rms),满足常规物理实验运行条件下对激光参数调控的精度和效率需求。

Laser pulse shape is one of the most critical parameters for the success of inertial confinement fusion experiments.The ability to shape the laser pulse with accuracy,efficiency,and robustness is fundamental for highpower laser facility with individual characteristics and independent adjustability for each beam.An autonomous pulseshaping method is established by employing an iterative algorithm and some strategies,solving the problem of nonlinear response in the pulse-shaping process,as well as improving the convergence rate.The test results indicate that it is capable of shaping an almost arbitrary pulse waveform at the accuracy of better than 10%(rms)of the deviances within 20 iterations or about 10 min,even a 23∶1 high-contrast-pulse waveform can be done with high quality of pulse and measure condition.With this method,the precise control on the laser pulse shape and the operational efficiency can fully meet the experimental requirements.