Optical Pulse Train Generation Using Soliton Compression Of The Beat Signal Between Two Optical Carriers

Generation of high-repetition-rate (10-150 GHz) optical pulse trains may be required at numerous points within future time-domain optical networks, including at transmitters, receivers regenerators, multiplexor/demultiplexors, etc. There: are a wide range of techniques for generating such pulse trains including gain switched lasers, active and passive modelocking of bulk and fiber lasers, electroabsorptive modulators, and soliton compression of the beat signal between two CW lasers. The latter technique has shown promise as a source tunable (in repetition rate and wavelength) very high repetition-rate (>lo0 GHz) pulse streams.[l-41 The basic technique is shown in Figure 1. Two CW lasers are combined, amplified, and compressed using standard fiber, dispersion shifted fiber, or custom dispersion tailored fiber. The combined effects of dispersion and the nonlinear index of refraction lead to generation of near-transform-limited soliton pulse trains whose repetition rate is equal to the frequency separation between the two laser sources. Therefore very high repetition rates can be achieved with out the need for high frequency electronics.