  We experimentally demonstrate the Talbot effect resulting from the repeated
self-reconstruction of a spatially intensity-modulated probe field under the
Fresnel near-field regime. By launching the probe beam into an optically
induced atomic lattice (established by interfering two coupling fields) inside
a rubidium vapor cell, we can obtain an diffracted probe beam pattern from an
formed electromagnetically induced grating (EIG) in a three-level
$\Lambda$-type Doppler-free atomic configuration with the assistance of
electromagnetically induced transparency (EIT). The EIG-based diffraction
pattern repeats itself at the planes of integer multiple Talbot lengths, which
agrees well with the theoretical prediction [Appl. Phys. Lett., 98, 081108
(2011)]. In addition, fractional EIT-induced Talbot effect was also
investigated. Such experimentally demonstrated EIT Talbot effect in a
coherently-prepared atomic system may pave a way for lensless and
nondestructive imaging of ultracold atoms and molecules, and further
demonstrating nonlinear/quantum beam dynamical features predicted for
established periodic optical systems.
