Goal of this work is to study methodic of designing optical fiber and wireless link and to program an application which will be able to calculate power budget of specified link. Power budget of the link is the most important part of designing an optical fiber or wireless link because it tells us if it’s even possible to realize such connection or how many optical repeaters and amplifiers are needed. The bachelor thesis has three parts. The first part describes designing of optical fiber link (limitation by attenuation and dispersion) and various components that are needed (laser diode, optical fiber etc.). The second part describes designing of optical wireless link and atmospheric transfer environment (attenuation by beam spreading, attenu...