A variable optical attenuator is used to control the power of Light signals being transmitted through optical fibers. Variable optical attenuators reduce signal power in a Fiber by adjustable amounts.

With single Mode fibers for example, the signal may be too strong IF the distance between the devices using the signal is too short. Reducing the strength of a signal is necessary to avoid errors in Data transmissions that can occur when a the signal being transmitted is too strong for the receiving device.

Variable attenuators can be used with single mode, Multimode and Polarization maintaining fiber. There is low Insertion Loss and back Reflection with the use of variable attenuators.