Detection system comprising a transmitter portion and a receiver portion, in which the transmitter portion comprises at least: - a light source arranged to generate a main light beam (Fp); - a first element comprising a reflective zone arranged to generate a first reflected light beam from a first portion of the main light beam and a first aperture produced through the reflective zone and arranged to let pass a second portion of the main light beam; - a second element comprising a reflective zone arranged to generate a second reflected light beam from the second portion of the main light beam, and in which the receiver portion comprises photoreceptor means and a processing unit connected to the photoreceptor means and arranged to determine a detection state depending on generated electrical signals output by the photoreceptor means, the photoreceptor means comprising: - a first photoreceptor device arranged to receive the first reflected light beam; - a second photoreceptor device arranged to receive the second reflected light beam, the transmitter portion and the receiver portion being arranged in an optical fork, the transmitter portion being arranged in a first arm of the optical fork and the receiver portion in a second arm of the optical fork, thus allowing passage of an object between the two arms of the fork to be detected. - a light source arranged to generate a main light beam (Fp); - a first element comprising a reflective zone arranged to generate a first reflected light beam from a first portion of the main light beam and a first aperture produced through the reflective zone and arranged to let pass a second portion of the main light beam; - a second element comprising a reflective zone arranged to generate a second reflected light beam from the second portion of the main light beam, and in which the receiver portion comprises photoreceptor means and a processing unit connected to the photoreceptor means and arranged to determine a detection state depending on generated electrical signals output by the photoreceptor means, the photoreceptor means comprising: - a first photoreceptor device arranged to receive the first reflected light beam; - a second photoreceptor device arranged to receive the second reflected light beam, the transmitter portion and the receiver portion being arranged in an optical fork, the transmitter portion being arranged in a first arm of the optical fork and the receiver portion in a second arm of the optical fork, thus allowing passage of an object between the two arms of the fork to be detected. and in which the receiver portion comprises photoreceptor means and a processing unit connected to the photoreceptor means and arranged to determine a detection state depending on generated electrical signals output by the photoreceptor means, the photoreceptor means comprising: - a first photoreceptor device arranged to receive the first reflected light beam; - a second photoreceptor device arranged to receive the second reflected light beam, the transmitter portion and the receiver portion being arranged in an optical fork, the transmitter portion being arranged in a first arm of the optical fork and the receiver portion in a second arm of the optical fork, thus allowing passage of an object between the two arms of the fork to be detected. - a first photoreceptor device arranged to receive the first reflected light beam; - a second photoreceptor device arranged to receive the second reflected light beam, the transmitter portion and the receiver portion being arranged in an optical fork, the transmitter portion being arranged in a first arm of the optical fork and the receiver portion in a second arm of the optical fork, thus allowing passage of an object between the two arms of the fork to be detected.