Frequency Shifting of Femtosecond Pulses by Reflection at Solitons

The frequency shifting of an ultrashort optical pulse through reflection at a fundamental soliton is experimentally investigated in a microstructured optical fiber. The frequency up- and down-conversion is observed with efficiencies up to 70%. Through employing femtosecond pulses, relevant features of the interaction are highlighted, and the role of either the leading or the trailing edge of the soliton is proven.