Abstract: A system for sorting articles includes a feed conveyor for launching the articles across an airspace toward a first destination. A light source shines light energy on the articles in the airspace. A collector collects light energy reflected from the articles. A deflector is provided for deflecting selected articles toward an alternative destination as the articles fly across the airspace. A control system is operably connected to the collector and the deflector for actuating the deflector in response to a sensed parameter, such as an electromagnetic radiation frequency spectrum, of the light energy collected in the collector. Preferably, this system is utilized with a retro-reflector located on an opposite side of the airspace from the light source and the collector. This system also preferably includes the use of a multi-plexer which allows a single analyzer unit to be utilized to analyze light signals from each of a large plurality of collector units of the collector.