macrobend

1. In an optical fiber, a macroscopic deviation of the fiber axis from a straight line. Note 1: Macrobends are distinguished from microbends. Note 2: In optical fibers, macrobend radii must be greater than both (a) the minimum bend radius, i.e., the radius that will break the fiber, and (b) the critical radius, i.e., the radius at which substantial lateral radiation will occur. 2. A relatively large-radius bend in an optical fiber, such as might be found in a splice organizer, a fiber optic splice tray, or a fiber optic cable that is bent. Note:A macrobend will not cause a significant radiation loss if it is of sufficiently large radius, the loss depending on the radius and the type of optical fiber. Single-mode (SM) optical fibers have a low numerical aperture (NA), usually less than 0.15, and thus are more susceptible to bend losses than other types. Usually an SM fiber will not tolerate a critical radius (CR) of less than 6 cm (centimeters). Certain specialized SM fibers can...