Supercontinuum generation without residual pump peak through multiple coherent pump seeds

Residual pump peak in fiber-based supercontinuum, as a general phenomenon, limits its practical application. We report a novel supercontinuum generation (SCG) in a conventional highly nonlinear fiber (HNLF) through multiple coherent pump technique, which eliminates the residual pump peak existed in conventional SCG. The multiple coherent pump technique is realized by double bound-state solitons achieved from a homemade modelocked fiber laser. We further compare the SCGs pumped by conventional bound-state soliton and single soliton. It confirms that the effective elimination of the residual pump peak in supercontinuum owes to higher transferring efficiency of the pump energy to new generated frequencies in the multiple coherent pump scheme. The use of multiple coherent pump scheme, i.e., double bound-state solitons, provides a new, simple and promising method to obtain flat supercontinuum source.