  A driven resonator with focusing Kerr nonlinearity shows stable localized
structures in a region far from modulational instability. The stabilization
mechanism is based on front interaction in bistable regime with an
inhomogeneous injected field. The experimental setup consist of a focusing Kerr
resonator filled with a liquid crystal and operates in negative optical
diffraction regime. Engineering diffraction is an appealing challenging topic
in relation with left-handed materials. We solve the visible range of current
left-handed materials to show that localized structures in a focusing Kerr
Fabry-Perot cavity submitted to negative optical feedback are propagating
fronts between two stable states. We evidenced analytically, numerically, and
experimentally that these fronts stop due to the spatial inhomogeneity induced
by the laser Gaussian forcing, which changes spatially the relativity stability
between the connected states.
