Model studies of fiber-optical communication channels in quantum cryptographic systems

Dedicated to model studies of fiber-optic communication channels (FOCC) in quantum cryptographic systems (QCS). There are two main problems with the use of QCS related to the reliability of information transfer. The analysis of the energy loss factors in the classical fiber-optic channel has been carried out and the additive loss formula in it is discussed in detail. The fiber-optic channel of quantum information transmission using integrated optical devices is considered. The additive formula of optical losses in such a channel is discussed. The features of losses in integrated optical devices are shown, in particular light attenuation in optical fiber, losses on bends and micro-bends, technological, dispersion and transition losses. The features of quantum cryptographic system of information transmission are characterized. For example, when constructing a model of a photo detector, three main parameters are taken into account: quantum efficiency, speed, noise level. As a result, the model of FOCC QCS taking into account energy losses is proposed, which allows competently in theoretical terms and visualize the passage of information through modern quantum cryptographically secure telecommunications while providing control in government structures.