A photon echo experiment in Tm3+:YAG is reported that shows, for the first
time to the authors' knowledge, the time-domain equivalent of the transitio
n from near- to far-field diffraction, including Talbot self-imaging effect
s. The experiment demonstrates the huge dispersion capability of photon ech
oes and opens the way to further exploration of space-time duality. (C) 199
9 Optical Society of America OCIS codes: 190.4380, 070.6760, 070.4790, 200.
4740.