High Power, Picosecond Phase Coherent Pulse Sequences by Injection Locking

Abstract

Complex multiple pulse sequences have proven extremely valuable in NMR as probes of intermolecular and intramolecular interactions. Optical analogs of many of these sequences can be useful in elucidating the effects of collisional perturbation in gases, guest-guest and guest-host interactions in mixed molecular crystals, or any general perturbations which make the usual two-level approximations invalid. But all 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 radiofrequencies [1]. We present here a new technique which extends the applicability of phase coherent pulse sequences to high powers and ~ 200 ps resolution, and should be extendable to even shorter pulses.