DOI: 10.22184/2070-8963.2026.135.3.54.62
The paper provides an overview of typical telecommunication optical fibers, with mentioning of standardized methods identification their geometric characteristics, and provides various examples of fiber cross-section images using an optical microscope and specialized measuring devices. Attention is paid to the most commonly used optical measurement methods and the selection of appropriate equipment. Some individual features of various designs of modern telecommunication fibers are noted, the detailed study of which is often necessary to determine the type, category and the scope of fiber application.