HARMONIC-GENERATION BY LASER-DRIVEN CLASSICAL HYDROGEN-ATOMS
|Title||HARMONIC-GENERATION BY LASER-DRIVEN CLASSICAL HYDROGEN-ATOMS|
|Publication Type||Journal Article|
|Year of Publication||1992|
|BANDARAGE, G, Maquet, A, MENIS, T, Taieb, R, Veniard, V, COOPER, J|
|Journal||PHYSICAL REVIEW A|
|Date Published||JUL 1|
We present the results of our investigations of the dynamics of a classical hydrogen atom submitted to an intense classical radiation field with a relatively low frequency as compared to the characteristic Kepler frequency of the atomic system. We discuss here the harmonic spectra which can be deduced from a Fourier analysis of the time evolution of the strongly driven atomic dipole, associated either with a single trajectory or with ensembles of trajectories evolving from an initial microcanonical distribution. The spectra obtained from ensemble-averaged atomic dipoles qualitatively reproduce the main features of those recently observed in experiments and allow, in particular, discussion of the occurrence of a plateau in the distribution of harmonic intensities as a function of their order. The possible competition between harmonic generation and multiphoton ionization, which both take place in the same laser-intensity range, is also discussed.