Is the index of refraction of a glass optical fiber consistent for all wavelengths?

The index of refraction of a glass optical fiber is not consistent for all wavelengths of light. This phenomenon is known as chromatic dispersion, where different wavelengths of light travel at different speeds when passing through a medium like glass. As a result, the refractive index changes slightly depending on the wavelength.

In practice, this means that shorter wavelengths (like blue light) generally have a higher index of refraction than longer wavelengths (like red light). Because of this inconsistency, signals made up of multiple wavelengths can spread out over time, leading to potential degradation of signal quality in fiber optic communications. Understanding this principle is crucial for designing optical systems, as it impacts bandwidth and performance.