Which type of loss is associated with bending of fiber and reduces attenuation performance?

• A. Absorption
• B. Bending Losses
• C. Scattering
• D. Reflections

Answer: (B)

Light is guided in a fiber by keeping it inside the core through total internal reflection. When the fiber is bent, the light path shifts and some of the light no longer meets the condition for total internal reflection at the core–cladding boundary. That light leaks into the cladding and escapes, increasing attenuation. This specific loss mechanism is known as bending losses, and it becomes larger with tighter bends and with higher-order light modes.

Absorption is energy loss inside the material turning into heat, not tied to bending. Scattering arises from tiny imperfections in the fiber that redirect light in many directions. Reflections occur at interfaces (like terminations or connectors) due to the Fresnel effect, not because of bending. So bending losses are the reason bending of the fiber reduces attenuation performance.

In practice, to minimize this, engineers use fibers designed for tight bends and maintain adequate bend radii during installation.