Realization of femtosecond soliton oscillation in all-fiber Raman laser with soliton self-frequency shift suppression

In order to obtain the true oscillation of femtosecond solitons in fiber Raman lasers where relatively long fibers are usually used, it is necessary to suppress the soliton self-frequency shift (SSFS) in fibers. The oscillation of femtosecond solitons in a synchronously pumped all-fiber Raman ring laser by suppressing the SSFS effect is described. It is shown that proper choices of both the Stokes oscillation wavelength and pump power level are required for SSFS suppression. Optical pulses as short as 400 fs with low-amplitude noise have been generated from the compact fiber Raman laser.>