Experimental observation of front propagation in LL model with negative diffractive and inhomogeneous Kerr cavity

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.