Could you explain the significance of your article to the non-specialist?

An innovative experimental strategy to measure three-pulse photon-echo data is presented; experimental data allowing to construct the photon-echo peak-shift, which in turn is determined by the interaction of the solvated molecule with its environment. It is shown that not only the photon-echo peak-shift but also the width of the photon-echo contains information on the intramolecular vibrations, which will considerable simplify the analysis of the complex experimental data. 

What has motivated you to conduct this work?

A strong motivation for this work was to develop an alternative experimental outline that allows for easy and fast data collection of the entire information contained in a homodyne detected photon-echo experiment. In future work, this will allow to discuss and simulate dynamic processes measured by this powerful technique without basing the discussion on one-dimensional projections of the entire data set. 

Where do you see this work developing in the future?

(i) As indicated above we will pursue the work presented here showing that besides the photon-echo peak-shift, the echo-width as a function of population time exhibits additional details on the investigated system-bath interactions. The newly accessible information will be incorporated into the discussion and simulation of the data. (ii) We will turn to the investigation of more complex systems such as cyanines, model systems for the biologically extremely relevant process of photoinduced isomerization. Furthermore, investigations on solar cell materials and conducting polymers are to come. 

Are there any particular challenges facing future research in this area?

As said above, the work presented here, opens the doorway of understanding the multi-dimensional data set available from a homodyne detected three-pulse photon-echo experiment without relying on one-dimensional projections of the data. In general, work on chromophore-environment interactions will be of great importance and challenge in order to understand the structure-function relationship in proteins providing specially designed environments for directing particular chemical reactions.