Abstract

Time-dependent methods, coupled to the single active electron approximation (SAE), have yielded detailed calculations of electron and photon emission rates from rare gas atoms in strong laser fields [1]. An example of such calculations is shown in Figure 1, where optical harmonic generation (OHG) rates are compared to above threshold ionization (ATI) rates for xenon at intensities between 1 and 5 x 10¹³ W/cm². It is now well-established that the comparison of these rates to experiment results in excellent agreement [2-3]. Figure 1 also illustrates a striking difference between these high-order strong field processes: OHG exhibits a cutoff while ATI does not. Our efforts to understand this fact have led to the view of very high-order strong field processes which we present in this paper.

© 1994 Optical Society of America