The Legrand indoor/outdoor fiber optic cable features 16 single-mode OS2 cores, LSZH construction, Euroclass Dca s2 d2 a1 fire safety, and a loose tube design for resilience and easy LAN/WAN backbone installation. It details the fiber's geometrical, optical. In fiber-optic communication, a single-mode optical fiber, also known as fundamental- or mono-mode, is an optical fiber designed to carry only a single mode of light - the transverse mode. Modes are the possible solutions of the Helmholtz equation for waves, which is obtained by combining. The number of optical cores in an optical fiber is the total number of equipment interfaces multiplied by 2, plus 10% to 20% of the spare quantity, and if the communication mode of the equipment has serial communication and equipment multiplexing, you can reduce the number of cores.