Physical Review Letters
Temporal, Matter-Wave-Dispersion Talbot Effect
L. Deng, E. W. Hagley, Johannes Hecker Denschlag, J. E. Simsarian, Mark Edwards, Charles W. Clark, Kristian Helmerson, S. L. Rolston, William D. Phillips
Abstract
We analyze and experimentally demonstrate a new (temporal) Talbot effect, where a pulsed phase grating is applied to a cloud of cold atoms (Bose-Einstein condensate). In contrast to the usual (spatial) Talbot effect, our atoms gain kinetic energy when diffracted by the pulsed grating. The energy gain and the matter-wave-dispersion relation result in an exact (no paraxial approximation) Talbot effect where the initial wave front is reconstructed at multiples of a ``Talbot time'' ${T}_{\mathrm{T}}$. We demonstrate the Talbot effect by applying a second pulsed phase grating after a variable delay. When this second grating is applied at even (odd) multiples of ${T}_{\mathrm{T}}/2$, it doubles (cancels) the effect of the first pulsed grating.