H_2^+分子阈下谐波极化起源的理论研究

Theoretical study on the origin of ellipticity of below-threshold harmonics from H_2^+ molecules

近来人们已经研究了H_2^+分子较低阶阈下谐波的极化,研究表明基态和激发态之间的共振对这些较低阶谐波的极化有重要影响。该文通过求解含时薛定谔方程的方法研究了较高阶阈下谐波的极化。结果表明:激发态仅对较小取向角下的较高阶阈下谐波的极化有影响;此外,长短电子轨道之间的干涉也对较高阶阈下谐波的极化有重要影响。该文的结果可对分子阈下谐波极化的复杂起源提供参考。

The ellipticity of lower-order below-thlreshold harmonics （BTHs） from H2 ＋ has been studied re- cently, and it has shown that the resonance between the ground state and the excited states plays an important role in the ellipticity of lower-order BTHs. In this paper, we study the ellipticity of higher-order BTHs from H2 ＋ through numerical solution of the time-dependent Schrodinger equation. Our simulations show that the in- fluence of the excited states on the ellipticity oflaigher-order BTHs is remarkable at smaller orientation angles. Moreover, the interference between the long and short electron trajectories plays an important role in the ellip- ticity of higher-order of BTHs. Our studies shed light on the complex origin of ellipticity of BTHs from mole- cules.