Which of the following are primary causes of intrinsic loss in single-mode fiber?

Intrinsic loss in single-mode fiber primarily refers to the losses that occur due to the inherent properties of the fiber itself, rather than external factors or imperfections. Material absorption and Rayleigh scattering are two main processes that lead to intrinsic loss in single-mode fibers.

Material absorption occurs because certain wavelengths of light are absorbed by the glass material of the fiber, converting optical energy into heat, which results in signal loss. This absorption is a function of the material's composition and the wavelength of the light being transmitted.

Rayleigh scattering is a phenomenon that results from the microscopic variations in the density of the fiber material, causing the light to scatter as it travels along the fiber. This scattering is dependent on the wavelength; shorter wavelengths experience higher scattering losses, which contributes to the overall attenuation of the signal.

Both of these factors are inherent to the fiber material and cannot be remedied through external adjustments, which is why they are classified as intrinsic loss causes. Understanding these sources of loss is crucial for fiber optic design and performance expectations, as they influence the overall efficiency and effectiveness of data transmission over long distances.