Wavelength tunable high-repetition-rate picosecond and femtosecond pulse sources based on highly nonlinear photonic crystal fiber

We demonstrate an actively mode-locked dispersion-managed erbium fiber laser and a Raman soliton wavelength converter that use photonic crystal fibers (PCFs) as the nonlinear medium. The high nonlinearity and large anomalous dispersion of the PCF resulted in a significant reduction in the length. We generated 1.0-ps pulses tunable over 1535-1560 nm at a 10-GHz repetition rate and 1.3-ps pulses at a 40-GHz repetition rate from a laser that was only 36 m long. Furthermore, we obtained 10-GHz femtosecond solitons, tunable over a 90-nm range, by means of soliton self-frequency shift of the mode-locked laser pulses in a 12.6-m-long PCF.