How many wires are in fiber optic cable? A fiber optic cable doesn't contain wires in the traditional electrical sense. Instead, it contains optical fibers, which are thin strands of glass or plastic that transmit data as pulses of light. Unlike copper wires, which are limited by lower data transmission speeds, shorter transmission distances, and higher susceptibility to electromagnetic interference, fiber optic cables offer unparalleled performance and can. 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.