10-GHz 1.3-ps pulse generation using chirped soliton compression in a Raman gain medium

The authors demonstrate a novel pulse compression technique that is capable of producing high-quality 1.3-ps pulses at a repetition rate of 10 GHz. The technique begins with 20-ps pulses carved by a commercially available external modulator and achieves up to 15-fold compression using a combination of phase modulation and distributed Raman amplification. Unlike adiabatic soliton compression, the scheme takes advantage of an exact solution to the nonlinear Schrodinger equation for chirped soliton evolution. As such, high-quality low-pedestal compressed pulses can be produced in a shorter span of fiber than would be needed for adiabatic compression. Because the system uses external modulation, the source is inherently tunable. Furthermore, the degree of pulse compression can be adjusted by varying the amount of Raman gain and phase modulation.