Investigation of the operation of a fiber-optic communication line at extremely low temperature conditions.

The necessity of additional research of mechanical and optical characteristics, assessment of operability and degradation of special optical fibers with a core doped with GeO2 in extremely low temperature operation is justified. The application of a model for the destruction of optical fibers is considered, which makes it possible to evaluate the mechanical properties of quartz fibers with a core of pure quartz and doped with germanium oxide. An experimental setup has been developed and research has been conducted. It has been found that with an increase in the degree of doping of the optical fiber core with germanium oxide, the limit of the increase in optical losses at low temperatures shifts towards zero. This creates restrictions on the use of doped core fibers when operating on highways. The obtained data allow the developers of fiber-optic communication lines, taking into account climatic conditions, to develop an optimal design of the main communication line, taking into account the MSVD and VAD manufacturing of optical fibers.