Application of a λ/4-shifted DFB laser/electroabsorption modulator monolithically integrated light source to single-chip pulse generator with variable repetition rate

The authors have demonstrated the application of a 1.55-μm λ/4-shifted DFB laser/InGaAsP electroabsorption modulator monolithically integrated light source to a single-chip pulse generator with variable repetition rate for soliton transmission for the first time. Quasi-transform-limited pulses with a time-bandwidth product of 0.31 were successfully generated up to 8.6-GHz repetition rates by the sinusoidally driven integrated modulator having high modulation efficiency of 13 dB/V. No change of lasing wavelength was observed in the operation scheme of the integrated device as a pulse generator.