Bends microbends

Microbending Loss. As a result of their small diameters, optical fibers bend very readily. This feature is advantageous in that the transmission medium is very flexible and easily routed. However, when the spatial period of the bending becomes small (approx. 1 mm or less), some of the light rays normally guided by the fiber are lost through radiation. Such small period distortions may occur when a fiber is wound on a spool under tension or when it is placed in cable structure. The phenomenon is termed microbending (11), and... 

The term microbending refers to short period (about 1 mm) and small amplitude (typically a few microns) random bends which are able to couple optical modes in such a way that they leave the core... 

This chapter is mainly concerned with the power radiated from single-mode fibers due to bending. We first consider losses from bends of constant radius, and then examine losses due to random, but slight, curvature along the fiber, commonly known as microbends. Bending losses for multimode fibers are described by the ray methods of Chapter 9. 

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