Patent ID: 7936512

Claim:
An optical gating system that, in a same manner as performing an opening and closing operation of a gate, controls passage of signal light incident on a gate region which functions as the gate, by using a moiré effect, said optical gating system comprising: a first spatial characteristic light emission unit configured to convert the signal light to first spatial characteristic light whose intensity distribution has spatial periodicity, and emit the first spatial characteristic light to the gate region so that the first spatial characteristic light is obliquely incident on the gate region; and a second spatial characteristic light emission unit configured to emit, to the gate region, second spatial characteristic light whose intensity distribution has spatial periodicity, the second spatial characteristic light acting to change an intensity of the first spatial characteristic light in the gate region when overlaid with the first spatial characteristic light in the gate region, wherein in a predetermined one of an open state and a closed state in the opening and closing operation, a moiré fringe pattern is created in the gate region by overlaying the first spatial characteristic light and the second spatial characteristic light, and in another one of the open state and the closed state in the opening and closing operation, the moiré fringe pattern by the second spatial characteristic light is not created in the gate region.