A laser system is provided that includes a laser unit, an incoupling means for coupling the laser radiation into a light-guide, and an outcoupling means for coupling the laser radiation out from the light-guide. A data transmitting means is coupled to the incoupling means or outcoupling means and produces optical signals which are coupled into the light-guide via the incoupling means or the outcoupling means. These optical signals are received by a data receiving means at the other end of the light-guide. The laser system can be used for realizing a data communication between the hand-piece and the stationary unit of the laser system in the case of which additional cables between the hand-piece and the laser are not necessary for transmitting data.