  We report intermittent large-intensity pulses that originate in Zeeman laser
due to instabilities in quasiperiodic motion, one route follows torus-doubling
to chaos and another goes via quasiperiodic intermittency in response to
variation in system parameters. The quasiperiodic breakdown route to chaos via
torus-doubling is well known, however, the laser model shows intermittent
large-intensity pulses for parameter variation beyond the chaotic regime.
During quasiperiodic intermittency, the temporal evolution of the laser shows
intermittent chaotic bursting episodes intermediate to the quasiperiodic motion
instead of periodic motion as usually seen during the Pomeau-Manneville
intermittency. The intermittent bursting appears as occasional large-intensity
events. In particular, this quasiperiodic intermittency has not been given much
attention so far from the dynamical system perspective, in general. In both the
cases, the infrequent and recurrent large events show non-Gaussian probability
distribution of event height extended beyond a significant threshold with a
decaying probability confirming rare occurrence of large-intensity pulses.
