Time-domain Fresnel-to-Fraunhofer diffraction with photon echoes

A photon echo experiment in ${\mathrm{Tm}}^{3+}:\mathrm{YAG}$ is reported that shows, for the first time to the authors’ knowledge, the time-domain equivalent of the transition from near- to far-field diffraction, including Talbot self-imaging effects. The experiment demonstrates the huge dispersion capability of photon echoes and opens the way to further exploration of space–time duality.