The diploma thesis describes the elaboration of a program for the simulation of an optical transmission path. The work introduces the basic parameters of optical transmission, such as attenuation, dispersion and bandwidth. Furthermore, the techniques of line code and error detection are described in the work, especially a cyclic redundancy sum. The key parameter of this thesis is dispersion of the optical signal. The work includes the characteristics of the eye diagram and its analysis. The resulting program can also be used to measure the real transmission route and its parameters.