发散光束抽运的宽带光参量啁啾脉冲放大系统的理论研究

Theoretical study of optical parametric chirped pulse amplification pumped by divergent beams

对发散光束抽运的光参量啁啾脉冲放大器的增益带宽进行了系统的理论研究.采用空间傅里叶变换和四阶Runge-Kutta算法,分别模拟了非衍射极限情况下的高斯光束和空间频谱为矩形的发散光束作为抽运光时的增益曲线.结果表明:不管是在可见光或是在近红外光谱区,用发散光束均可以明显地改善光参量啁啾脉冲放大系统的增益带宽.选取合适的发散角和抽运光强,可以获得高增益、宽谱带的信号光输出.

The gain bandwidth of optical parametric chirped pulse amplification pumped by divergent beams has been theoretically studied. Several gain curves are simulated when the pump are non-diffraction-limited Gaussian beams or a beams having rectangular distribution in spatial spectrum respectively, using the method of Fourier transform and the fourth-order Runge-Kutta algorithm. The results show that the gain bandwidth of optical parametric chirped pulse amplification can be obviously improved by using divergent pump beams, either in the visible or in the near infrared region. Very high gain and broadband spectrum can be obtained if the divergence angle and intensity of the pump is selected properly.