Abstract

We simulate numerically the multiphoton ionization of a 1-D quasihydrogenic model atom.¹ The time-dependent Schrodinger equation is integrated as a partial differential equation in space and time using the Crank-Nicholson algorithm, and the numerical wave functions are subsequently exploited to compute both the photoelectron energy spectrum and the intensity distribution of laser harmonics in scattered light. Two specific applications are discussed in detail. First, we followed the Keldysh-Faisal-Reiss (KFR) procedure for our 1-D model atom and compare the KFR predictions with the results of direct integration of the Schrodinger equation. In our parameter range (ten-photon ionization at intensities ~10¹⁴ W cm^–2), poor agreement between the KFR models and the simulations is found. Second, we have compared the electron and photon spectra collected side by side in our numerical experiments. A semiquantitative agreement between the two kinds of spectra is established. In multiphoton ionization, the production of ionized electrons and highorder harmonics of the laser radiation appear to be closely linked.

© 1989 Optical Society of America