Ricerc@Sapienza

The buildup process of coherent structures and patterns from the composite balance between conservative and
dissipative effects is a universal phenomenon that occurs in various areas of physics, ranging from quantum
mechanics to astrophysics. Dissipative solitons are highly coherent solutions of nonlinear wave equations, and
provide an excellent research platform for ultrafast transient phenomena. Herein, by taking advantage of the fast
detection technique provided by the dispersive Fourier transform, we experimentally observe the spectral
broadening and breathing behavior of transient dissipative structures produced asynchronously during the
buildup process of dissipative solitons. These observations unveil a novel dynamics of dissipative soliton generation,
which is accompanied by energy quantization, self-phase modulation induced spectral broadening,
structural dissipative soliton formation, and Raman soliton self-frequency shifting, thus providing a new insight
in transient ultrafast laser dynamics.