  Domain walls in type I degenerate optical parametric oscillators are
numerically investigated. Both steady Ising and moving Bloch walls are found,
bifurcating one into another through a nonequilibrium Ising--Bloch transition.
Bloch walls are found that connect either homogeneous or roll planforms.
Secondary bifurcations affecting Bloch wall movement are characterized that
lead to a transition from a steady drift state to a temporal chaotic movement
as the system is moved far from the primary, Ising--Bloch bifurcation. Two
kinds of routes to chaos are found, both involving tori: a usual Ruelle-Takens
and an intermittent scenarios.
