Lopsided diffractions of distinct symmetries in two-dimensional non-Hermitian optical gratings
Authors: Liu YM., Gao F., Wu JH., Artoni M., La Rocca G.C.
Autors Affiliation: Northeast Normal Univ, Sch Phys, Changchun 130024, Jilin, Peoples R China; Jilin Univ, Coll Phys, Changchun 130012, Jilin, Peoples R China; Brescia Univ, Dept Engn & Informat Technol, I-25133 Brescia, Italy; Brescia Univ, CNR, Ist Nazl Ott, I-25133 Brescia, Italy; Scuola Normale Super Pisa, I-56126 Pisa, Italy; CNISM, I-56126 Pisa, Italy
Abstract: Fraunhofer light diffraction across a thin two-dimensional lattice of cold atoms subject to transverse hybrid modulations of two standing-wave crossed pump fields is seen to yield lopsided patterns of various degrees of symmetry. We show that one can fully restrain the diffraction of a weak incident probe to two diagonal or adjacent quadrants or even just to a single quadrant, depending on the phases of two standing-wave pumps and on the probe detuning. Different diffraction symmetries with respect to the axes or diagonals of the diffraction plane quadrants are interpreted here in terms of different out-of-phase interplay of absorption and dispersion periodic distributions, resulting from different combinations of Hermitian, PT-symmetric, and non-Hermitian modulations
Journal/Review: PHYSICAL REVIEW A
Volume: 100 (4) Pages from: 043801-1 to: 043801-7