Earle K. Plyler Prize for Molecular Spectroscopy & Dynamics Talk: Two-Dimensional Femtosecond Spectroscopy

In 1976, Ernst demonstrated Two-Dimensional Fourier transform (2D FT) spectra in Nuclear Magnetic Resonance (NMR). 2D FT NMR is now routinely used in medical imaging and the determination of biomolecule structures in solution. In 1998, my group demonstrated the first optical analogs of 2D FT NMR spectra. These 2D FT electronic spectra were recorded by using femtosecond lasers and exploiting nonlinear optical phase matching, a phenomenon with no analog in NMR. Using the same technique, 2D FT infrared vibrational spectra followed two years later. It is well known that femtosecond pulses can be used to time resolve vibrations in molecules and phonons in solids. Femtosecond 2D FT spectra spread these signals out over two frequency dimensions. The femtosecond time resolution of 2D FT spectra “freezes” such vibrational motion and can also