source of illumination(n = noun.artifact) - any device serving as a source of visible electromagnetic radiation;
is a kind of device
has particulars: lamp, light, light source, ultraviolet lamp, ultraviolet source

dark field illumination, dark ground illumination, illumination, illumination unit, light source, passive source, point source, quasi-stellar radio source, radio source, source, source book, source code, source language, source materials, source program, ultraviolet illumination, ultraviolet source