核运动对H_(2)^(+) 和D_(2)^(+) 谐波截止区域强度的影响

Effect of nuclear motion on harmonic cutoff intensity of H_(2)^(+) and D_(2)^(+)

理论研究了不同激光条件下H_(2)和D_(2)谐波截止附近区域强度的变化.结果显示,在低激光强度下,当采用短脉宽激光场时,H_(2)谐波强度大于D_(2)谐波强度.随着脉宽增大,D_(2)谐波强度增强并且大于H_(2)谐波强度.在高激光强度下,当采用短脉宽激光场时,虽然H_(2)谐波强度依然大于D_(2)谐波强度,但其强度差比低激光强度时有所减小.当采用长脉宽激光场时,D_(2)谐波强度大于H_(2)谐波强度.理论分析表明,不同尺度的核运动是导致H_(2)和D_(2)谐波辐射强度不同的原因.

The intensity of harmonic cutoff region of H_(2) and D_(2) driven by different laser conditions has been studied theoretically. The results show that for the lower laser intensity case, the harmonic yield of H_(2) is higher than that of D_(2) when the shorter pulse duration is used. As the pulse duration increases, the harmonic yield of D_(2) will be enhanced and higher than that of H_(2) . For the higher laser intensity case, when the shorter pulse duration is used, the intensity difference of harmonic yield is decreased, though the harmonic yield of H_(2) is still higher than that of D_(2) . When the longer pulse duration is used, the harmonic yield of D_(2) is much higher than that of H_(2) . Theoretical analyses show that the different harmonic yields of H_(2) and D_(2) is attributed to different time scales of nuclear motion.