Ultrafast spatial coherent control methods for transition pathway resolving spectroscopy of atomic rubidium.

We demonstrate the use of the ultrafast spatial coherent-control method to resolve the fine-structure two-photon transitions of atomic rubidium. Counter-propagating ultrafast optical pulses with spectral phase and amplitude programmed with our optimized solutions successfully induced the two-photon transitions through 5S(1/2)-5P(1/2)-5D and 5S(1/2)-5P(3/2)-5D pathways, both simultaneously and at distinct spatial locations. Three different pulse-shaping solutions are introduced that combine amplitude shaping, which avoids direct intermediate resonances, and phase programming, which enables the remaining spectral components to be coherently interfered through the targeted transition pathways. Experiments were performed with a room-temperature vapor cell, and the results agree well with theoretical analysis. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement