A list of the most popular single mode optical fibers from leading manufacturers Corning, OFS, Prysmian, and Sumitomo. This comprehensive guide examines the top fiber optic. Fiber optic cables are the backbone of modern telecommunications infrastructure, enabling high-speed data transmission across vast distances with minimal signal loss. ) on DirectIndustry, the industry specialist for your professional purchases. OS1 single mode fiber optic cables are made with a single mode fiber core, which means that they have a very small core diameter of 9 microns. Although they can do the same job in some instances, the different construction methods make each of them better suited to certain tasks and budgets.