使用速度成像法测得了405 nm飞秒激光脉冲下H+的动能分布和角分布。讨论了解离通道H+2→H++H、 H2+2→H++H+的反应路径, 前者产生于经由1ω交叉的直接单光子路径,后者产生于H2+2的库仑爆炸。H+2到H2+2的电离起始于键软化, 各通道的相对峰高说明H+2的解离和电离是竞争的。低场强加强H+2的解离,高场强支持H+2的电离。

The kinetic energy and angular distributions of H+ as a function of 405 nm femtosecond laser intensity are experimentally measured by using velocity map imaging technique. The reaction pathways of dissociation channels, H+2→H++H and H2+2→H++H+, are discussed. The former is due to the direct one-photon pathway via the 1ω crossing, and the latter stems from Coulomb explosion of H2+2. Ionization of H+2 to H2+2 starts from bond softening. The relative yield of fragment peak indicates that dissociation and ionization of H+2 are competitive. The lower laser intensity emphasizes the dissociation of H+2, and the higher laser intensity favors the ionization of H+2.