Two-dimensional electronic spectroscopy

Two-dimensional Fourier transform electronic spectroscopy is demonstrated. Non-collinear three-pulse scattering allows selection of electronic coherence order by choice of phase-matching geometry, temporal pulse order, and Fourier transform variables. Detection of the scattered field at the sample allows separation of the real (absorptive and emissive) and imaginary (refractive) contributions to the 2D spectra. The experiments reported here are electronic analogs of the 2D magnetic resonance techniques known as COSY (correlated spectroscopy) and NOESY (nuclear Overhauser effect spectroscopy) and should allow detection of electronic multiple quantum coherence.