With respect to other nonlinear spectroscopic techniques, 2DES has the following advantages:
(i) It is possible to separate, and thus distinguish, contributions to the nonlinear signal that are spectrally overlapped in one-dimensional experiments. Analysis of cross-peaks reveals whether the different transitions seen in the sample absorption spectrum arise from the same or different molecular species and can quantify couplings and correlations between different excited states.
(ii) 2DES removes inhomogeneous broadening and thus measures the homogeneous linewidth of optical transitions, enabling the individual levels to be singled out in strongly congested spectra.
(iii) 2DES can follow the parallel pathways by which the coupled electronic dynamics evolve after photoexcitation in real time. This makes the 2D technique a particularly powerful tool for tracking excitation energy transfer processes from origin to terminus through multiple channels simultaneously.
(iv) 2DES overcomes the Fourier limit, obtaining simultaneously high temporal resolution (to follow dynamics occurring on the femtosecond timescale) and spectral resolution (to resolve excitation and emission energies over significant bandwidths with high spectral accuracy).
(v) It is possible to retrieve structural information on the relative spatial arrangement of the chromophores, by either probing the intermolecular electronic couplings through the analysis of the cross-peaks or manipulating the pulse polarizations. 2DES can connect the molecular structure (determined by X-ray crystallography) with the electronic energy levels and, in favorable cases, it can provide insight into the molecular structure when unknown.