The need for access to information is determined by to the rapid development of high capacity fiber optic transmission systems (FOTS). This system improvement has been due to the fact that only has a small loss of SiO2 fiber and realize high-speed (R> 10 Tbit / s) optical devices. Powerful laser devices and small distance between the transmitted channels have to develop high capacity fiber optic transmission systems, capable of transmitting information over long distances. This development has become a cause of various phenomena of nonlinear effects in optical fibers, because relatively small fiber diameter and large input intensity of light caused by non-linear optical effects. Experimentally nonlinear optical effects with picosecond and nanosecond laser pulses in optical fibers was studied. A picosecond laser spectrometer pulse was measured, nonlinear optical loss dependence on light intensity and wavelength was obtained and an experimental result was analyzed. With increasing light intensity, was observed ambiguous optical loss change. During the course of explaining the reasons behind the significant potential, to evaluate their formation mechanisms, as well as the Raman amplifier designed for use in optical wavelength-division multiplexing systems, caulking, where there is a standard single-mode optical fiber distance up to 100 km, which is characteristic of Latvian FOTS. In the research original measuring equipment shall designed to measure the average power for picoseconds laser pulses with low ( Hz) pulse repetition frequency. With the help of a power meter was evaluated laser pulses spectral characteristics and measured losses in optical fibers. The study was carried out in the minimum energy (6.5 kt / bit) calculation of the optical transmission and detection, to determine to what extent can reduce the signal power of optical communication channels.