Understanding optimal control results by reducing the complexity

Exploring the role of phase modulation on photoluminescence yield

We report an investigation to elucidate the mechanisms of control in phase-sensitive experiments in two molecular systems. A first inspection of optimization procedures yields the same experimental result: increase in the emission efficiency upon excitation by a phase modulated pulse in a two-photon transition. More detailed studies, which include power dependence, spectral response, one and two color pump-probe and pump-pump experiments show that while for one chromophore phase modulation leads to spectral matching between the two-photon cross section and the second order power spectrum for the other it provides a tool to manipulate the wavepacket dynamics in the excited state.