OPTICAL ATTENUATOR

In optical communications , a device used to reduce the power level of an optical signal . Note 1: Optical attenuators used in fiber optic communications systems may use a variety of principles for their functioning. Those using the gap-loss principle are sensitive to the modal distribution ahead of the attenuator , and should be used at or near the transmitting end, or they may introduce less loss than intended. Optical attenuators using absorptive or reflective techniques avoid this problem. Note 2: The basic types of optical attenuators are fixed, step-wise variable, and continuously variable.