The growing demand of using optical communication systems, either by increasing the number of users or the amount of information sent, requires a substantial increase in the need to develop new systems and components. The optical time domain re ectometry (OTDR) is the most common technique for detecting faults in fiber optic links. In some types of optical network, such as passive optical networks (PONs), losses in the links are very high due to the presence of splitters that divide the signal to each user (in FTTH scenario) or each user group ( FTTB / FTTA), which considerably reduces the maximum distance reached by the OTDR. In terms of components used for optical communication, those used for optical amplification is of great importance. Among them are present optical semiconductor amplifiers. One way to overcome the limitations imposed by high losses is the use of a semiconductor optical amplifier (SOA), which at the same time amplifies the signal and acts as a key, inhibiting the emission ASE in the intervals between the OTDR pulses. Still, the additional gain may be insufficient due to low saturation power SOA. This work will develop experimentally a method to overcome the limitation of saturation of an SOA and allow higher amplification gains for OTDR pulse. The basic concept is to take advantage of the fact that the use of an OTDR cycle is relatively low, which allows to split the pulses into sub-pulses, amplify them one by one and then recombine them in a transparent manner to the OTDR. Based on the idea proposed above, this master thesis will be evaluated using methods polarization and wavelength of the pulses.