Strong-field control landscapes of coherent electronic excitation

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Atomic, molecular, and optical physics, 2008-04, Vol.41 (7), p.074007-074007 (13)
• Main Authors: Bayer, Tim, Wollenhaupt, Matthias, Baumert, Thomas
• Format: Article
• Language: English
• ISSN: 0953-4075; 1361-6455
• DOI: 10.1088/0953-4075/41/7/074007

We report on physical mechanisms behind resonant strong-field coherent control. To this end, we study multi-photon ionization of potassium atoms using intense shaped femtosecond laser pulses. The measured photoelectron spectra are discussed in terms of selective population of dressed states (SPODS). A physically motivated pulse parameterization is introduced which opens up two-dimensional parameter spaces comprising pulse sequences as well as chirped pulses. The control topologies of these subspaces are mapped out experimentally and are presented in the form of strong-field control landscapes (SFCLs). In the SFCLs, complementary realizations of SPODS via photon locking and rapid adiabatic passage are observed. Moreover, the combined effect, termed Multi-RAP, arises when both mechanisms are at play simultaneously. In order to better understand the performance of adaptive optimization procedures, we experimentally study their capability to find optimal solutions on a given parameter space. The evolution of different optimization procedures is visualized by means of control trajectories on the surface of the measured SFCL.