570 fs pulses from a Pr ³⁺ -doped fibrerlaser modelockedby pump pulse induced cross-phasemodulation

Abstract

The authors report for the first time subpicosecond pulse generation by pump pulse induced cross-phase modulation in an active fibre. By synchronously pumping a Pr3+-doped fluoride fibre with 90 ps Nd:YAG laser pulses, 570 fs pulses at 1.3 µm were obtained using intracavity dispersion compensation. It was found that the introduction of a polarisation dependent loss into the cavity allows different repetition rates of the fibre laser to be selected and is essential for obtaining stable pulse trains.