The process through which $ATP$ is synthesised by cells is named phosphorylation. Photophosphorylation is formation of $ATP$ in presence of light. It may be of two types cyclic and non cyclic.
Non cyclic photophosphorylation involves both $PS I$ and $PS II$. Cyclic photophosphorylation involves $PSI$ only and occurs in stromal lamellae which lack both $PS II$ and $NADP$ reductase enzyme. Photocentre of $PS I $ is excited by wavelength o f $700\, nm$ (beyond $680\, nm)$. The excited electron does not pass onto $NADP^{+}$ but is cycled back to $PS I$ through electron transport chain hence only $ATP$ is synthesised but not $NADPH + H^{+}$