Abstract: An optical shutter comprising a frame with an aperture and shutter blade for modulating a light beam or a particle stream passing through the aperture. The top end of the shutter blade comprises a first sector and a second sector, each sector having different optical characteristics. The bottom end of the shutter blade is coupled to a motor means for pivotally rotating the shutter blade over a limited angular range in a clockwise and counter-clockwise direction such that the first sector is aligned with the aperture when the shutter blade is rotated in one direction and the second sector is aligned with the aperture when the shutter blade is rotated in the other direction.

Abstract: A safety shutter suitable for intercepting an energy beam. The safety shutter includes at least one shutter blade having a top end and a bottom end. At least one motor is coupled to the bottom end of the shutter blade such that the motor rotates the shutter blade from a closed position to an open position when energized. The shutter blade is coupled to at least one spring, wherein the spring rotates the shutter blade from the open position to the closed position when the motor is de-energized.