What causes macrobending loss, and how can it be identified using an OTDR?

Macrobending loss is caused by excessive bending of an optical fiber, where the bend radius is significantly larger than the fiber's diameter but still too tight for the fiber's specifications. When a fiber is bent, the light traveling within the core attempts to follow the curve. If the bend is too sharp, some of the light rays exceed the critical angle for total internal reflection and escape from the core into the cladding. This escaping light is lost, resulting in increased attenuation, known as macrobending loss. The amount of macrobending loss depends on sev....