G. Izus et al., Phase-locked spatial domains and Bloch domain walls in type-II optical parametric oscillators - art. no. 056231, PHYS REV E, 6405(5), 2001, pp. 6231
We study the role of transverse spatial degrees of freedom in the dynamics
of signal-idler phase locked states in type-II optical parametric oscillato
rs. Phase locking stems from signal-idler polarization coupling which arise
s if the cavity birefringence and/or dichroism is not matched to the nonlin
ear crystal birefringence. Spontaneous Bloch domain wall formation is obser
ved numerically and the dynamics and chiral proper-ties of the fronts are i
nvestigated. Bloch walls connect homogeneous regions of self-phase-locked s
olutions by means of a polarization transformation. The parameter range for
phase locking is found analytically. The polarization proper-ties and the
dynamics of walls in one and two transverse spatial dimensions are explaine
d. The transition from Bloch to Ising walls is characterized, the control p
arameter being the linear coupling strength. The wall dynamics governs spat
iotemporal dynamical states of the system, which include transient curvatur
e driven domain growth, persistent dynamics dominated by spiraling defects
for Bloch walls, and labyrinthine pattern formation for Ising walls.