Widely wavelength tunable ultrashort soliton pulse and anti-Stokes pulse generation for wavelengths of 1.32-1.75 μm

Using dispersion shifted polarization maintaining optical fibers and a femtosecond fiber laser, a compact system of widely wavelength tunable ultrashort pulse generation is demonstrated in the wavelength region of 1.32-1.75 mu m. The clear sech(2) soliton pulse and the anti-Stokes pulse are generated simultaneously. The wavelengths of the two pulses are shifted to the opposite wavelength sides by changing the fiber input power. The maximum conversion efficiencies are as large as 65% for the soliton pulse and 10% for the anti-Stokes pulse. The soliton pulse and the anti-Stokes pulse copropagate along the fiber. The mechanism of the wavelength shift of the anti-Stokes pulse is also discussed.