Object detection systems are provided herein. An example system includes an enclosure formed by a sidewall to define an interaction volume, at least one light source for illuminating the interaction volume with a light, at least one light sensor that senses disturbances in light intensity due to scattering, reflection, or absorption of the light by objects within the interaction volume, and a controller that is configured to detect an object or object behavior within interaction volume based on the disturbances in the light intensity.