Linear stability analysis predicts that transverse modulation instability (MI) can occur for two optical beams copropagating in a Kerr nonlinear metamaterial (MM) interacting with each other through cross-phase modulation. A detailed discussion on the role of cross-phase modulation-induced coupling between beams on MI is presented, and it is found that MMs will enrich the propagating characteristics of beams. MI that occurs when beams are in different refractive-index regions is particularly interesting since it is a precursor to the formation of bright and dark spatial solitons. Furthermore, transverse MI can develop for different combinations of the signs of refractive index decided by the two beams, respectively, which makes the temporal MI in optical fibers find its transverse MI counterpart in MMs. Based on the Drude model, numerical simulations are performed to confirm theoretical predictions.
© 2009 Optical Society of America
Original Manuscript: September 12, 2008
Revised Manuscript: December 7, 2008
Manuscript Accepted: January 17, 2009
Published: March 3, 2009
Xiaoyu Dai, Yuanjiang Xiang, Shuangchun Wen, and Dianyuan Fan, "Modulation instability of copropagating light beams in nonlinear metamaterials," J. Opt. Soc. Am. B 26, 564-571 (2009)