Vector single- and double-hump solitons for the coupled Sasa-Satsuma equations in optical media

Abstract

In this paper, we investigate the coupled Sasa–Satsuma equations for the propagation of the ultrashort pulse in optical media. Through the binary Bell polynomials and introduction of three auxiliary functions, bilinear form, vector single- and double-hump soliton solutions in bright-dark form are obtained. To our knowledge, vector double-hump solitons in bright-dark form have not been studied in the existing literature. Based on those solutions, (i) parametric conditions for the existence of the vector single- and double-hump solitons, (ii) four types of soliton amplitudes and (iii) the interval between the two peaks for the double-hump soliton are presented analytically.

Keywords:

• Coupled Sasa–Satsuma equations
• vector solitons
• soliton interaction
• binary Bell polynomials
• auxiliary function

Notes

No potential conflict of interest was reported by the authors.

Additional information

Funding

This paper has been supported by the Fund of State Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications), by the Fundamental Research Funds for the Central Universities of China [grant number 2015RC19], by the National Natural Science Foundation of China [grant number 11272023], by the Fundamental Research Funds for the Central Universities of China [grant number 2011BUPTYB02], and by the Specialized Research Fund for the Doctoral Program of Higher Education [number 200800130006], Chinese Ministry of Education.