Abstract

Complex multiple-pulse sequences have proven extremely valuable in nuclear magnetic resonance (NMR) as probes of intermolecular and intramolecular interactions. Optical analogs of many of these sequences can be useful in elucidating the effects of collisional perturbations in gases, guest-guest and guest-host interactions in mixed molecular crystals, or any general perturbations that make the usual two-level approximations invalid.¹ But all of these sequences require phase coherence (the phase of each pulse must be specified relative to the first), which was more difficult to achieve in optical spectroscopy than at radio frequencies.

© 1984 Optical Society of America