Calculating Ionization Transition Rate for Circularly Polarized Fields, Including Non-Zero Initial Momentum

Abstract

Potassium atoms in circularly polarized laser field whose intensity (I) varies from 2 × 1012 W/cm2 to 2.5 × 1014 W/cm2 were studied. In the case when there is zero initial momentum, transition rate (that depends only on I) exhibits standard behaviour: as I increases, so thus the rate, until it reaches its maximum value at 1.1 × 1014 W/cm2 ; after that, rate diminishes as I increases. In the case of non-zero initial momentum, transition rate (that now depends on I but additionally on initial momentum, too) exhibits following behaviour: dependence of the rate on I follows standard pattern, it rises with increase of I until it reaches its maximum, and then diminishes. But with increase of momentum, ionization rate gradually diminishes.