  We demonstrate theoretically and experimentally that a specifically designed
microcavity driven in the optical parametric oscillation regime exhibits
lighthouse-like emission, i.e., an emission focused around a single direction.
Remarkably, the emission direction of this micro-lighthouse is continuously
controlled by the linear polarization of the incident laser, and angular beam
steering over \unit{360}{\degree} is demonstrated. Theoretically, this
unprecedented effect arises from the interplay between the nonlinear optical
response of microcavity exciton-polaritons, the difference in the subcavities
forming the microcavity, and the rotational invariance of the device.
