Waveguides of subwavelength dimensions with asymmetric geometries, such as
rib waveguides, can display nonlinear polarization effects in which the
nonlinear phase difference dominates the linear contribution, provided the
birefringence is sufficiently small. We demonstrate that self-flipping
polarization states can appear in such rib waveguides at low (mW) power levels.
We describe an optical power limiting device with optimized rib waveguide
parameters that can operate at low powers with switching properties
