Optical dark soliton trains generated by passive spectral filtering technique

A new technique for the generation of fundamental dark soliton trains with uniform intensity background is described. The signal emitted by a multigigahertz repetition rate mode-locked laser source is temporally shaped by high resolution spectral filtering. The proposed shaping device is all-optical and passive. The emitted dark pulses are shown to propagate soliton-like over distances compatible with telecommunication applications.