Import 03/11/2016This diploma thesis is dealing with study of Bragg grating exposed to high optical power. In theoretical part are described 2 most popular optical amplifiers used in telecommunications, based on semiconductors and on rare earth doped fibre. Also in this part are presented basic principles of Bragg grating and consequences of exposing it to external physical factors. Practical part includes measurement of parameters of Bragg grating before and after exposure to high optical power. For exposing grating to high optical power, will be built a source using optical amplifiers, for obtaining power values greater than usually used in communication environment. Source will be verified if its spectrum corresponds to spectrum of grat...