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

The zero-dispersion point in single-mode fiber is strategically moved to 1,550 nm primarily to take advantage of the fiber's low intrinsic absorption and significantly reduced attenuation at this wavelength. At 1,550 nm, the optical loss in the fiber is at its minimum, which means signals can travel longer distances without needing as much amplification. This characteristic allows for efficient signal transmission, making it ideal for telecommunications.

Additionally, the inherent properties of the materials used in fiber optics, such as silica, exhibit lower loss and better performance at 1,550 nm compared to other wavelengths. This optimal balance between minimal dispersion and low attenuation makes it the preferred choice for long-haul fiber optic communication systems.

The other options, while relevant to fiber optics in various contexts, do not directly pertain to the rationale for positioning the zero-dispersion point at this specific wavelength. For instance, operating temperature, manufacturing costs, or splice loss are not the primary factors driving the decision to optimize performance at 1,550 nm.