In fiber-optic communications, the reduction of optical signal power as light propagates down the fiber is called what?

Introduction / Context:
Optical links carry information as light through glass or plastic fibers. As light travels, some energy is lost due to absorption, scattering, and other mechanisms. The overall reduction in signal power per unit distance is a key design parameter because it dictates repeater/amplifier spacing and receiver sensitivity requirements.

Given Data / Assumptions:

• The question asks for the general name of power loss in a fiber.
• We are not computing a value; we are identifying the correct term.
• Typical contributors include absorption, Rayleigh scattering, and macrobending/microbending losses.

Concept / Approach:
Total loss along the fiber is called attenuation, usually expressed in dB/km. While “scattering” names one physical cause of loss, the umbrella term that quantifies the outcome (power reduction from input to output) is attenuation.

Step-by-Step Solution:
Recognize we need the general effect, not a specific mechanism.Map “reduction in power with distance” to “attenuation.”Confirm that other terms either describe causes (scattering) or unrelated ideas (propagation simply means travel).

Verification / Alternative check:
Link budget calculations sum fiber attenuation (e.g., 0.2 dB/km at 1550 nm) with splice/connector losses to verify that received power stays above receiver sensitivity plus margin.

Why Other Options Are Wrong:
propagation: Not a loss term; it just means signal travel.

scattering: A mechanism of loss, not the total measured reduction.

interruption: Implies a break or outage, not gradual loss.

None of the above: Incorrect because attenuation is the accepted term.

Common Pitfalls:
Confusing specific mechanisms (scattering) with the aggregate metric (attenuation), or mixing attenuation with dispersion (temporal spreading, not power loss).

Final Answer:
attenuation