We numerically study the gray solitons in parity-time (PT) symmetric potentials. Simulated results show that there are two kinds of gray solitons, the dip-shaped gray solitons and the hump-shaped solitons, and both of them can be stable. Hump-shaped solitons can always exist, but the grayness of a stable dip-shaped gray soliton should exceed a threshold value. More interesting, it is discovered that when propagating in PT symmetric potentials, the gray solitons have no transverse deviation, and this is a phenomenon different from the usual gray solitons.
© 2011 Optical Society of America
Original Manuscript: May 26, 2011
Revised Manuscript: July 26, 2011
Manuscript Accepted: July 28, 2011
Published: August 15, 2011
Huagang Li, Zhiwei Shi, Xiujuan Jiang, and Xing Zhu, "Gray solitons in parity-time symmetric potentials," Opt. Lett. 36, 3290-3292 (2011)