Which factor is used to quantify the loss of signal strength in a fiber optic link?

Which factor is used to quantify the loss of signal strength in a fiber optic link?

• A. Attenuation
• B. Dispersion
• C. Reflection
• D. Bandwidth

Answer: (A)

Loss of signal strength in a fiber optic link is quantified by attenuation. Attenuation describes how optical power decreases as light travels through the fiber, typically expressed as a loss value per length (like dB per kilometer) or as a total dB loss over the entire link. It accounts for all the ways the signal is diminished: absorption within the fiber, scattering from the glass, bending losses, and losses at splices or connectors. Because it directly measures how much of the original signal actually makes it to the receiver, attenuation is the right measure of forward power loss. Dispersion, on the other hand, is about the spreading of the optical pulse in time because different wavelengths travel at different speeds, not about overall power loss. Reflection relates to light bounced back toward the source at interfaces, which affects back reflections rather than forward signal strength. Bandwidth concerns the data-carrying capacity of the link, not how much power is lost.

Loss of signal strength in a fiber optic link is quantified by attenuation. Attenuation describes how optical power decreases as light travels through the fiber, typically expressed as a loss value per length (like dB per kilometer) or as a total dB loss over the entire link. It accounts for all the ways the signal is diminished: absorption within the fiber, scattering from the glass, bending losses, and losses at splices or connectors. Because it directly measures how much of the original signal actually makes it to the receiver, attenuation is the right measure of forward power loss.

Dispersion, on the other hand, is about the spreading of the optical pulse in time because different wavelengths travel at different speeds, not about overall power loss. Reflection relates to light bounced back toward the source at interfaces, which affects back reflections rather than forward signal strength. Bandwidth concerns the data-carrying capacity of the link, not how much power is lost.