Because the bending of fiber optic cables might cause certain damage, the curvature should not be too slight. The minimum bend radius under pulling tension should typically be 20 times the diameter of fiber optic cables. Damage may not always be obvious, like a kink in the cable, but may include broken fibers, fibers with higher loss due to stress and cable structural damage that may lead to reliability problems. Note:. Fiber optic cable bend radius is a critical mechanical parameter that determines how sharply a cable can be bent without risking microbending, macrobending, signal loss, or long-term structural fatigue. It is measured from the inside of the bend, not the outer curve. For an quick, simple overview of fiber optics, you can use one of these three options: 1) the Fiber U self-study program Fiber Optics in Communications and How It Works, 2) the FOA YouTube Videos Fiber Optics and Communications and How To "Talk" Fiber Optics or 3) Lennie Lightwave's Guide To Fiber. The bend radius of fiber cables is critical for maintaining high performance and longevity. In operational fiber networks, it represents a fundamental mechanical–optical boundary.