The thermal welding method involves the use of a special welding machine that produces an electric arc that melts the ends of the optical fibers, connecting them together. Abstract: This paper presents the welding phases of optical fibers and welding technology of five types of optical fiber in following combinations: unimodal, multimodal and with modified dispersion. A qualified fiber end face is a necessary condition for welding, and the end surface quality affects the quality of the. Therefore, for single-mode cables with fibers in the G. 657A2 standard, the maximum bending radius is 7. 657B). There are several methods to achieve this. Fibre optic Internet is currently the most desired connection.