Tunable femtosecond soliton generation from continuous diode lasers using pulsed stimulated Raman amplification

The single-pass soliton–Raman generation process1 provides an expansive spectral continuum that contains several solitons of sub-picosecond duration. However, the spectral extent of the continuum and the number of solitons contained in it are not particularly controllable, although they are a function of the pump power. Consequently, the soliton–Raman continuum is of limited use as a practical wavelength-tunable, femtosecond-pulse source. By using spectral filtering, a wavelength band of interest can be selected. This method does give rise to considerable overall system energy loss, but the solitons so selected can be used for pump-probe experiments.2