Observation of electromagnetically induced Talbot effect in an atomic system with nonlinearity

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.