How does water affect the glass core of an optical fiber?

Water can significantly affect the glass core of an optical fiber, primarily because glass is a porous material. The presence of water can lead to various forms of degradation within the fiber, particularly by causing scattering and absorption of light as it travels through the core. When the core becomes opaque due to water absorption, it disrupts the transmission of light signals, ultimately leading to a degradation of signal quality.

This effect is crucial to understand, as optical fibers are designed to transmit light signals efficiently and any obstruction or degradation—such as from the presence of water—can compromise their performance. The glass core is meant to facilitate the total internal reflection of light, and anything that interferes with this process, like water making the material partially opaque, negatively impacts signal clarity and strength.

While there might be other effects that water could potentially have on an optical fiber's performance, the core becoming opaque and degrading the signal is a significant concern, making this answer the most accurate in the context of understanding how water interacts with the fiber's glass core.