Wavelength tunable 10-GHz 3-ps pulse source using a dispersion decreasing fiber-based nonlinear optical loop mirror

We experimentally demonstrate the use of a dispersion decreasing fiber (DDF)-based nonlinear optical loop mirror (NOLM) for the generation of wavelength tunable soliton-like pulses at a repetition rate of 10 GHz. We compress ∼12-ps Gaussian pulses from an electro-absorption modulator (EAM) (followed by 125 m of DCF for preliminary linear dispersion compensation) into 3-ps pedestal-free pulses using both high-order soliton compression and nonlinear switching effects within an 8.5-km DDF-based loop mirror. The output pulses from the DDF-based NOLM show considerable pedestal reduction compared to those obtained by directly compressing the EAM seed pulses via a single passage through the DDF. Wavelength tuning of the compressed pulses over a ∼15-nm bandwidth (from 1541 to 1556 nm) is demonstrated without a significant increase in pulse duration or degradation in pulse quality.