has part device light source obscuration bar optical filter optical subsystem A device or part of a device that deals with the behavior and properties of light and the interaction of light with matter. Commonly optical subsystems consist of an excitation optics and collection optics. The excitation optics of a flow cytometer optical subsystem consist of the laser and lenses that are used to shape and focus the laser beam. The collections optics consist of a collection lens to collect light emitted from the particle laser beam interaction and a system of optical mirrors and filters to route specified wavelengths of the collected light to designated optical detectors. The optical subsystem in a flow cytometer consists of the equipment used to irradiate particles, and collect the light either emitted or scattered by those particles. DS: Is 'subsystem' necessary or is 'optical_system' enough. Not sure its graph position since an optical subsystem is not necessarily an instrument, but more likely part of one. John Quinn Person: Daniel Schober optical subsystem optical subsystem of a cytometer metadata incomplete