Photoelectron angular distribution of atoms irradiated by intense linearly polarized laser fields

The development of nonperturbative quantum electrodynamics has made it possible to use exact wavefunctions and nonperturbative scattering theory to study multiphoton effects. Within this framework we develop a theoretical approach to interpret photoelectron angular distributions in terms of a generalized phase Bessel function which can determine the principal features of the distribution and its variation with laser frequency and intensity. Our theory has successfully explained a serious of experimental observations and predicted several new types of photoelectron angular distribution. A scaling law has also been established by this theory.