Optical Multidimensional Spectroscopy of Atomic Vapor

Optical multidimensional coherent SPECTROSCOPY

Coherent multidimensional optical spectroscopy.

Multidimensional optical techniques, the focus of this special issue, are analogues of their NMR counterparts; that is, rather than using spin transitions as little spies within a molecule, we use vibrational or optical transitions. Similar to NMR, the spectroscopic states often respond in a very sensitive way to their chemical environment. By modeling the coupling of one of these states to eit...

Ultrafast optical spectroscopy of spectral fluctuations in a dense atomic vapor.

Transient four-wave mixing experiments with 100 fs pulses in a dense potassium vapor probe the electronic energy fluctuations that lead to optical decoherence. Echo-peak shift experiments yield a biexponential two-time correlation function of energy level fluctuations. Molecular dynamics simulations show that the slow component is a many-body excitonic contribution arising from long-range reson...

Optical spectroscopy of atomic and molecular positronium

Positronium (Ps) is a purely leptonic hydrogen-like atom formed from an electron and a positron. Since the interactions of electrons and positrons are thought to be almost entirely electromagnetic, precision measurements of the Ps energy levels should constitute a good test of QED theory. The ultimate precision is limited by the rapid annihilation of the various Ps states and the number of Ps a...

Focus on multidimensional optical spectroscopy and imaging

Optical spectroscopy using ultrafast light pulses has undergone a revolution in the last decade due to the introduction and development of multidimensional coherent techniques. These methods build on established coherent spectroscopic techniques, such as photon echoes, but go beyond them by correlating the coherent dynamics during two time periods. The resulting multidimensional spectra have a ...