Name on picture provides some illumination (6)
I believe the answer is:
photon
'some illumination' is the definition.
(a photon is a light particle)
'name on picture' is the wordplay.
'name' becomes 'n' (common abbreviation e.g. on forms).
'on' is a charade indicator (letters next to each other).
'picture' becomes 'photo' (a photograph).
'n' put after 'photo' is 'PHOTON'.
'provides' acts as a link.
(Other definitions for photon that I've seen before include "Quantum particle of light" , "A little light" , "Tiny bit of light" , "Quantum of electromagnetic radiation" .)