In a fiber optic communication system an optical attenuator is an electronic device commonly used to decrease the level of power of an optical signal. In fiber optics, attenuation is also called transmission loss. Concerning the distance traveled by the signal in a transmission medium, it is the reduction in light signal intensity. To limit the transmission of a digital signal traveling in large distances, attenuation is an important element. As optical attenuator travels along with free space or an optical fiber it reduces this optical signal.
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