We report that surface defect superlattice solitons can be supported by a defect on the interface between the optical superlattices and the homogeneous media with saturable nonlinearity. The surface defect of superlattices offers such types of soliton some unique properties. For the positive defect, solitons exist in the semi-infinite bandgap, whereas for the negative defect, solitons exist not only in the semi-infinite bandgap but also in the first finite bandgap. When defect intensity approximates to the intensity of optical superlattices, solitons exist in the semi-infinite bandgap. The stable regions of solitons with various defects are given.
© 2007 Optical Society of America
Original Manuscript: March 16, 2007
Revised Manuscript: June 24, 2007
Manuscript Accepted: August 3, 2007
Published: September 14, 2007
Wu-He Chen, Ying-Ji He, and He-Zhou Wang, "Surface defect superlattice solitons," J. Opt. Soc. Am. B 24, 2584-2588 (2007)