Direct Observation of Pinning and Bowing of a Single Ferroelectric Domain Wall

We have made a direct optical observation of pinning and bowing of a single 180^∘{} ferroelectric domain wall under a uniform applied electric field using a collection mode near-field scanning optical microscope. The domain wall is observed to curve between the pinning defects, with a radius of curvature determined by the material parameters and the applied electric field. The change in birefringence with applied field is used to infer the orientation of the internal field at the domain wall.