ATP synthesis during light reaction is

ATP synthesis during the light reaction is Photophosphorylation.
In the process of photosynthesis, the phosphorylation of ADP to form ATP using the energy of sunlight is called photophosphorylation.
In photophosphorylation, light energy is used to pump protons across a biological membrane, mediated by the flow of electrons through an electron transport chain. This stores energy in a proton gradient.