The document discusses two types of bending loss that can occur in optical fibers: macroscopic bending, which occurs when a fiber is bent with a radius larger than the core radius, and microbending, which is minimized by using a protective jacket around the fiber. It also mentions several factors that contribute to bending loss, such as the attenuation constant, radius of curvature, number of guided modes, and core and cladding properties between step index and graded index fibers that determine the loss experienced by each mode.

1. UNIT II

26. Bending Loss

35. Macroscopic Bending
If a fiber bends and if the radius is more in bending when compared to
the core radius, then it is Macroscopic Bending

36. Macroscopic bending or Bending Loss
Attenuation Constant
Radius of Curvature
Number of Effective modes for a curved multimode fiber
Total guided modes in a straight fiber

39. Microbend – Minimizing method
Microbend loss reduces by a factor as follows by the use of jacket

40. Core Cladding Losses
Loss for a step index waveguide
Loss for a several lower order modes
Loss in a graded index fiber
The loss encountered by a given mode