Obtained from normal light sources
High resolution spectroscopy for structure of atoms and molecules

Obtained from laser sources
Multi-photon processes, Multi-step excitation processes, Nonlinear optical processes,  Rydberg and Autoionizing Levels, Ultra-trace analysis ( single atom detection), 

High intense laser pulse sources
Intense field regime, Above threshold ionization, Multiple ionization, High harmonic generation (up to 300), Coulomb explosion, Atomic Stabilization