Question

in a fiber - optic communication system, what allows light waves to travel long distances through the fibers without significant loss?
the absorption of light waves by the material in the fibers.
the reflection of light waves inside the fibers to avoid loss.
the diffraction of light waves around the walls of the fibers.
the refraction of light waves through different materials.

Explanation:

In fiber - optic communication, total internal reflection (a form of reflection) of light waves inside the fibers minimizes loss. Absorption would cause loss, diffraction is not the main mechanism for long - distance low - loss transmission, and refraction through different materials (without reflection) would not ensure long - distance travel without significant loss.

Answer:

The reflection of light waves inside the fibers to avoid loss.