Beyond the zero-diffraction regime in optical cavities with a left-handed material

The combination of right-handed and left-handed materials offers the possibility to design devices in which the mean diffraction is zero. Such systems are encountered, for example, in nonlinear optical cavities, where a true zero-diffraction regime could lead to the formation of patterns with arbitrarily small sizes. In practice, the minimal size is limited by nonlocal terms in the equation of propagation. We study the nonlocal properties of light propagation in a nonlinear optical cavity containing a right-handed and a left-handed material. We obtain a model for the propagation, including two sources of nonlocality: the spatial dispersion of the materials in the cavity, and the higher-order terms of the mean field approximation. We apply these results to a particular case and derive an expression for the parameter fixing the minimal size of the patterns. (C) 2009 Optical Society of America