The role of intermediate resonances in population of Rydberg states excited by a strong laser pulse*

We have studied structures of Rydberg state populations for hydrogen and helium atoms via multiphoton transitions induced by intense laser pulse using numerical solutions of the time-dependent Schr\"odinger equation. In the results will consider the dependence on wavelengths from ultraviolet to infrared, which allow us to analyze the role of intermediate states shifted in and out of multiphoton resonances. The impact of the low-lying excited states on the angular momentum distributions in Rydberg states will be discussed.