Observation of the Formation of the 0π Pulse

We have measured with 0.5-psec resolution the reshaping of small-area 7-psec laser pulses to 0π pulses due to their passage through an optically thick sodium cell. The reshaped pulses have a picosecond oscillatory structure characteristic of 0π pulses that extends over more than 100 psec. These observations are compared in detail with the predictions of theory and good agreement is obtained © 1984 The American Physical Society.