超强激光场中H_2~ 的隧道离解和波包演化

利用超强激光脉冲中分子与场相互作用的多电子态模型，数值模拟了分子波包在高低频超强激光场中的演化过程。结果发现，高频场中分子波包的扩展是渐进的，直到脉冲作用结束，分子才完全离解；而在低频场中，分子波包迅速隧穿到离解态，仅在脉冲的前几个周期，波包便溢出相互作用区。另外还比较了高低频场作用下分子的离解几率和离解碎片的动量分布。

Tunneling Dissociation and Wavepacket Evolution of H 2 in Superstrong Laser Fields

With the multielectronic states model for investigation of molecular behavior in superstrong laser fields,we simulate numerically the evolution procedure of a molecular wavepacket in the superstrong laser field. It results that for high frequency field the wavepacket evolves gradually, the molecule doesn′t fully dissociate until the end of the interaction. However,the molecular wavepacket tunnels quickly into the dissociative states. The wavepacket overflows the interaction region only in the first several periods of the laser pulse. In addition, we have also compared the dissociation probability and the momentum distribution of fragments in the high-frequency field with those in the low-frequency field.