In fiber optics, which factor contributes significantly to pulse dispersion over long distances?

The wavelength of the source light plays a significant role in pulse dispersion in fiber optics. In optical fibers, light can travel at different speeds depending on its wavelength due to the phenomenon known as chromatic dispersion. When multiple wavelengths are used simultaneously, as is common in wavelength-division multiplexing (WDM), each wavelength can travel at a slightly different speed through the fiber, which leads to the spreading of the pulse over time. This spreading can result in overlapping signals that degrade the quality of the communication over long distances.

Thus, choosing a light source with an optimal wavelength can help minimize this dispersion effect, allowing for clearer signal transmission even over extended distances. This is particularly important in high-speed data transmission where maintaining the integrity of the signal is crucial.