Extension of dispersion decreasing fiber-pulse shaping method for the optical time division multiplexing system source applications

The optical time division multiplexed (OTDM) transmission system has been a topic of continuous research due to their unique advantages over conventional NRZ based transmissions, including the possibility of nonlinearity based all-optical information processing, and tolerances on dispersions penalties in the link. Among various key technologies which enable the successful integration of OTDM system, a high repetition rate, transform limited pulse source still remains as one of the issues which require further optimization. Still, most pulse sources developed so far had one or more drawbacks to be used as an information carrier, with unavoidable problems like timing jitter, pulse dropping, or severe chirp in the pulse, inherent in their generation methods. The recently proposed pulse shaping method using dispersion decreasing fiber (DDF) resolved several past issues providing high quality pulse with exact signal timing, but the application mostly has been limited to ultra-high repetition rate above 100´s GHz. The required DDF length to generate a pulse stream at low repetition rate becomes close to thousands of km, making this approach impractical for OTDM application. We obtain a pulse train at moderate 10-20 GHz repetition rate still retaining the advantages from the DDF adiabatic pulse compression approach, while using a much shorter, practically achievable length of DDF.