What does attenuation refer to in optical fiber communication?

Attenuation in optical fiber communication refers to the loss of signal strength as the light travels through the fiber. This loss can occur due to various factors, including scattering of light within the fiber material and absorption by the fiber itself. Over long distances, attenuation can significantly affect the performance of the optical communication system, leading to a weaker signal at the receiver end. Therefore, understanding and measuring attenuation is crucial for designing effective communication systems, ensuring that the transmitted signal maintains sufficient strength to be properly interpreted by the receiver.

The other options, while related to optical fiber communication, do not correctly define attenuation. The speed of light in an optical medium pertains to the propagation speed within the fiber, capturing light refers to the fiber's ability to gather light from various sources, and the layer surrounding the core describes the structure of the fiber, specifically the cladding, but these aspects do not directly address the concept of signal power loss during transmission.