Basic properties and advantages of optical communication systems. Propagation of EM waves in the wave line of circular cross-section. Diffraction. Classification of fibers and application of certain types. Manufacture of optical fibers. Signal attenuation as a result of absorption, scattering and radiation. Coupling modes. Modal and chromatic bandwidth fiber. Nonlinear effects in optical fiber. Principles of optoelectronic signal conversion. Types of lighting and laser diodes. Photo detectors. Transmitters and receivers of optical signals. Coupling of optical sources and fibers. Connecting fibers. Optical couplers. Optical amplifiers. Balance of power in the system ‘’point-point’’. Balance of time for response establishment in the system ‘’point-point’’. Calculation for the case of distribution optical network. Wavelength Divisin Multiplex (WDM).