Abstract: Assemblies and methods are described that provide for monitoring output from light emitting sources, such as vertical-cavity surface-emitting lasers. In particular, the assembly includes an array of light emitting sources, an array of lenses, an array of photodiodes, and a controller. The light is emitted by the array of light emitting sources, which in turn is configured to emit light towards the array of lenses. A photo-induced current is generated at the array of photodiodes, which is arranged to receive light reflected off of the array of lenses. The assembly determines a change in operational status of one or more of the light emitting sources based on the photo-induced currents.