Abstract: An optical rotary transmitter which ensures the reliable transmission of optical signals in conjunction with a comparatively simple construction comprises two parts spaced apart from one another which are rotatable relative to one another about a common centre axis and the first of which comprises a first circular light coupler (10) and the second of which comprises a second circular light coupler (20). The light entrance and light exit surfaces of the two light couplers face one another. Each of the light couplers (10, 20) consists of collimators (11, 21) combined to form a respective collimator arrangement (16, 26), optical coupling elements (15, 25) being connected to said collimators.