Dispersion in optical fiber primarily causes what effect on a signal?

• A. Broadening of pulses, reducing bandwidth.
• B. Increased signal strength.
• C. Decreased latency.
• D. Improved signal clarity.

Answer: (A)

When a signal travels through an optical fiber, the pulse tends to spread out in time because different parts of the pulse travel at different speeds through the fiber. This dispersion causes the various spectral components (or modes) to arrive at the receiver at slightly different times, so the pulse broadens as it propagates. That broadening means that individual pulses start to overlap with their neighbors, making it harder to distinguish where one bit ends and the next begins. The result is intersymbol interference, which limits how quickly you can reliably send data and thus reduces the usable bandwidth. Dispersion doesn’t boost signal strength, nor does it reduce latency; it mainly distorts the signal by spreading it, which degrades signal quality.