Interference effects in the two-dimensional scattering of microcavity polaritons by an obstacle: phase dislocations and resonances

We consider interference effects within the linear description of the scattering of two-dimensional microcavity polaritons by an obstacle. The polariton wave may exhibit phase dislocations created by the interference of the incident and the scattered fields. We describe these structures within the general framework of singular optics. We also discuss another type of interference effects appearing due to the formation of (quasi)resonances in the potential of a repulsive obstacle with sharp boundaries. We discuss the relevance of our approach for the description of recent experimental results and propose a criterion for evaluating the importance of nonlinear effects.