Attenuation In Optical Fibers – from Visible Light to Infrared (635nm–1625nm)

Attenuation is the reduction in optical signal (amplitude and intensity) as it propagates along a fiber.

Attenuation is due to absorption, scattering and other loss mechanisms (such as impurities, bending, and coupling). Attenuation is usually expressed in dB or as a rate of loss per unit distance (dB/km).

The following picture shows the three wavelength windows being used in fiber optic communications.