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Modern nonlinear and coherent optics provides a great variety of possibilities to create many types of spatially distributed neural network optical systems and uses them to simulate the collective behavior of dynamics systems with nonlocal interactions (e.g., analogs of advanced neural networks).' We can point out the following basic properties of these systems: — intrinsic N-shape nonlinearity (bistable or multistable optical response); — existence of the local excitation transfer mechanism (e.g., diffusion); — possible implementation of large scale (nonlocal) interactions; All these requirements can be fulfilled in nonlinear 2-D feedback optical systems: in various nonlinear resonators and interferometers.2 Complexity and variety of nonlinear dynamic modes (different selfoscillation and dissipative structures, optical turbulence) observed in neural network optical systems with the simplest nonlocal interconnectors promote the search for principal most important models of large scale interactions and corresponding nonlinear dynamic structures. One of these models is one-dimensional rotational instability occurring in a neural network system with rotated field.3 Rotating waves observed in this system have been analyzed in detail.4 Theoretical and experimental research of 2-D models of optical neural networks appears to be most interesting. Implementing any type of "pure" nonlocal interconnectors in an optical experiment is a rather complicated task. Optical aberrations and some other factors result in the fact that additional "spurious" interactions affecting dynamic structures being formed in the system seem to be superimposed on a given type of nonlocal interconnectors. The only possibility to examine multiple nonlinear structures corresponding to a certain type of large scale interactions appears to be a comparative analysis of optical and numerical experiments in which the interconnect topologies can be defined in a "pure" form. 2-D selfoscillation structures observed in a neural network with 2-D optical feedback and nonlocal interconnectors have been studied in this paper. The simplest types of topological transforms, i.e., lateral inversion and rotation, are realized in optical and numerical experiments.
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