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Femtosecond pulse shaping, multiple-pulse spectroscopy, and optical control.

A review is presented of femtosecond pulse-shaping methods and their application to spectroscopy of atoms, molecules, and condensed materials. Pulse shaping can be used to generate femtosecond pulse sequences and other optical waveforms whose time-dependent amplitude, phase, frequency, and polarization profiles are all specified precisely. The light-matter interaction mechanisms through which such waveforms can be used for optical control over molecular and material responses are discussed. Most of the spectroscopic experiments conducted to date that involve shaped femtosecond waveforms are reviewed. These have involved control over coherent electronic responses of atoms, small molecules, and multiple quantum wells and control over coherent molecular and lattice vibrations. A selective review is presented of theoretical predictions and qualitative discussions of optical control possibilities involving complex ultrafast waveforms.