A scanning-system including transmit/receive paths, a transmitter, a receiver and a rotating-scanning-device. The transmitter emits radiation which propagates along an optical-axis on the transmit-path. The radiation from the target-object is detected by the receiver on the receive-path. The rotating-scanning-device includes an optical-system and a rotating-deflection-unit, which deflects the radiation of the transmit/receive paths. The optical-system includes a first-focusing-unit and a rotating-second-focusing-unit. The movements of the rotating-deflection-unit and the rotating-second-focusing-unit occur synchronously to ensure an alignment of the deflected radiation with the second-focusing-unit. The first-focusing-unit reproduces the radiation emitted by the transmitter on the rotating-deflection-unit so that the beam-diameter on the rotating-deflection-unit is reduced. The rotating-deflection-unit deflects the radiation onto the rotating-second-focusing-unit and the rotating-second-focusing-unit collimates the radiation toward the target-object. The rotating-second-focusing-unit reproduces the radiation from the target-object on the rotating-deflection-unit so that the beam-diameter on the rotating-deflection-unit is reduced, and the rotating-deflection-unit deflects the received radiation toward the receiver.