(1) In optical fiber, sharp but microscopic curvatures that create local axial displacements of a few microns and spatial Wavelength displacements of a few millimeters. One frequent cause is longitudinal shrinking of the Fiber buffer. But it also can result from poor Drawing or Cable manufacturing methods, installation, etc. See microbending loss. (2) Tiny bends in fiber that allow Light to leak out and increase loss. microbending occurs during installation and is usually unavoidable. Loss budget margins should account for microbending.
Microbending is sharp but microscopic curvatures that create local axial displacements of a few microns and spatial wavelength displacements of a few millimeters. Microbending can cause a loss in optical power.
Microbending is caused by the manufacturing process or mechanical stress. Microbends are detected using sensors.