By using a sodium atomic vapor we have observed a honeycomb-type multiple-diffraction pattern that was due to a grating induced optically by three noncollinear bichromatic excitation beams. In particular, when the two incident frequencies satisfy the two-photon resonance condition and the atomic density is high, the diffraction is enhanced by electromagnetically induced transparency, and strong Stokes and anti-Stokes components are generated in well-defined directions.
© 2005 Optical Society of America
(270.1670) Quantum optics : Coherent optical effects
(300.2570) Spectroscopy : Four-wave mixing
(300.6290) Spectroscopy : Spectroscopy, four-wave mixing
(300.6320) Spectroscopy : Spectroscopy, high-resolution
(300.6420) Spectroscopy : Spectroscopy, nonlinear
Ken-ichi Harada, Satoshi Tanaka, Tatsuya Kanbashi, Masaharu Mitsunaga, and Koji Motomura, "Electromagnetically induced diffraction in sodium vapor," Opt. Lett. 30, 2004-2006 (2005)