  Various physical structures exhibit a fundamentally probabilistic nature over
diverse scales in space and time, to the point that the demarcation line
between quantum and classic laws gets blurred. Here, we characterize the
probability of intermittency in the laminar-turbulence transition of a
partially mode-locked fiber laser system, whose degree of coherence is
deteriorated by multiple mode mixing. Two competing processes, namely the
proliferation and the decay of an optical turbulent puff, determine a critical
behavior for the onset of turbulence in such a nonlinear dissipative system. A
new kind of optical rogue waves, polarization rogue waves, is introduced at the
point of transition to polarization turbulence. The probabilistic description
of the puff-mediated laminar-turbulence polarization transition provides an
additional degree of freedom for our understanding of the complex physics of
lasers.
