Since fiber optic attenuators can be used with two types of fiber cables, single mode and multimode, optical attenuators can be classified into single mode type and multimode type. Since too much light may saturate the fiber optic receiver, optical attenuators are often deployed in the system to reduce the light power and achieve the best fiber. An optical attenuator, or fiber optic attenuator, is a device used to reduce the power level of an optical signal, either in free space or in an optical fiber. for achieving a suitable signal level for a data receiver in a telecom system. Their function is purely to introduce controlled loss, expressed in decibels.