To provide an optical gating system capable of performing single-shot, parallel, and ultrafast gating equal to or less than a subpicosecond, without depending on coherence. The optical gating system converts signal light to spatial characteristic signal light whose intensity distribution has spatial periodicity, and emits the spatial characteristic signal light to a gate region (13) so as to be obliquely incident on the gate region (13). In a closed state in an opening and closing operation of the gate region (13), a closed moiré fringe pattern (graph 11) is created in the gate region (13) by overlaying the spatial characteristic signal light and spatial characteristic closed light acting in a direction in which an intensity of the spatial characteristic signal light is decreased in the gate region (13). In an open state, an open moiré fringe pattern (graph 12) is created in the gate region (13) by overlaying the spatial characteristic signal light and spatial characteristic open light acting in a direction in which the intensity of the spatial characteristic signal light is increased in the gate region (13).