Why was the zero-dispersion point in single-mode fiber moved to 1,550 nm?

The zero-dispersion point in single-mode fiber was moved to 1,550 nm primarily to take advantage of the low intrinsic absorption and lower attenuation that occur at this wavelength. At 1,550 nm, the properties of the glass used in fiber optics allow for longer transmission distances with minimal signal loss. This characteristic is crucial for high-speed data communication, as it enables fiber to support high-bandwidth applications over long distances without requiring frequent signal boosting or regeneration.

By maximizing the efficiency of light transmission at this wavelength, fiber optic systems can achieve greater overall performance. Incorporating this knowledge into optical networks not only improves the reliability of data transmission but also reduces the operational costs associated with maintaining infrastructure that operates over shorter wavelengths, where attenuation may be higher.