An identification element has a transponder with a data-emitting transmission unit and with a data-receiving reception unit in order to communicate with a device for registering and/or controlling access authorization to spaces or objects. In addition, a control circuit is provided for the transmission unit and reception unit. The transponder is an optical transponder (1.1), the transmission unit of which is a light-emitting transmission unit (1.3) and the reception unit of which is a light-receiving reception unit (1.4). The optical transponder and an autonomous power supply are integrated into the identification element. The identification element is in the shape of a name plate or of an identification element of comparable size which is assigned to an object or body or is to be supported thereon. By virtue of the fact that the transmission unit (1.3) of the optical transponder (1.1) is operated by the control circuit (2.5) in such a way that it transmits optical pulses of less than or equal to 100 nanoseconds repeatedly per second and that the identification element is batteryless, a very small optical transponder is provided which requires little energy and no batteries.