  We consider the model of fiber-laser cavities near the zero-dispersion point,
based on the complex Ginzburg-Landau equation with the cubic-quintic
nonlinearity, including the third-order dispersion (TOD) term. It is well known
that this model supports stable dissipative solitons. We demonstrate that the
same model gives rise to several families of robust bound states of the
solitons, which exists only in the presence of the TOD. There are both
stationary and dynamical bound states, with oscillating separation between the
bound solitons. Stationary states are multistable, corresponding to different
values of the separation. With the increase of the TOD coefficient, the bound
state with the smallest separation gives rise the oscillatory state through the
Hopf bifurcation. Further growth of TOD leads to a bifurcation transforming the
oscillatory limit cycle into a strange attractor, which represents a
chaotically oscillating dynamical bound state. Families of multistable three-
and four-soliton complexes are found too, the ones with the smallest separation
between the solitons again ending by a transition to oscillatory states through
the Hopf bifurcation.
