Bending radius of single-core optical cable
The normal recommendation for fiber optic cable is the minimum bend radius under tension during pulling is 20 times the diameter of the cable (d). 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. As a bend is reduced to a critical value, though, some portion of light traveling at the core/cladding interface cannot be refracted back into the core.
Read More