title: Ultrahigh-frequency interference beats in transient, incoherent-light four-wave mixing.
abstract: An angled-beam, transient four-wave mixing experiment is described in which nanosecond-duration, broad-bandwidth excitation pulses are employed to measure picosecond collisional dephasing and subpicosecond interference beats in atomic Rb vapor. The 7.2-THz interference beat, which corresponds to a 237 cm(-1) Rb fine-structure splitting, is apparently the fastest material-specific beat yet observed. We discuss practical limitations on the time resolution attainable with this technique and propose means of circumventing them by using broad-bandwidth collinear excitation beams and an angled narrow-bandwidth probe.
authors.forename: J E
authors.initials: JE
authors.lastname: Golub
authors.forename: T W
authors.initials: TW
authors.lastname: Mossberg