光谱色散后的相位调制光束衍射特性研究

Research on the diffraction characteristics of phase modulated laser beams dispersed spectrally

用数值方法研究了激光驱动器系统中使用光谱色散平滑单元后光束的衍射特性.模拟结果表明,光谱色散会使光束衍射光斑变大,近场空间强度均匀性改善,而远场光斑内部存在光强接近于均匀分布的区域.进一步分析了光谱色散平滑单元中相位调制器的调制深度、调制频率及光栅色散系数等主要元件参数对光束传输特性的影响,发现在一定情况下光斑内部会出现较强的强度调制.

It is simulated numerically the transmission of beams phase modulated and spectrally dispersed by the unit for smoothing by spectral dispersion put in the laser driver for inertial confinement fusion. The results show that the diffraction spot of a spectrally dispersed beam becomes larger and its near-field uniformity is improved, while there exists area where the intensity is nearly even within the far-field spot. The effects of the main parameters of the electro-optic phase modulator and the grating in the unit on the diffraction characteristics of the beams are further discussed, and it is found that intensity modulation emerges in the far-field spot under some conditions.