Fiber Optic Attenuator is a component installed in a fiver optic transmission system that  reduces the power in the optical signal.It is often used to limit the optical power received by photo detector, in order to get the power needed.Based on different connectors, the attenuators can be classified as FC,SC,STLC,MU,etc. Based on different structures, there are types of flange type( Female to Female), Male to Female,In-line type. Or fixed type(attenuation value can’t be adjusted),mechanical variable type(attenuation value can be adjusted in specified range), and voltage variable type ( attenuation value can be adjusted in specified range.) Here, we classify them as 5 types:Fixed flange type ,fixed male-female type , flange mechanical variable type, In-line mechanical variable type and voltage variable type.

Attenuation value of this type is fixed with range of 0-30 dB.Normally there are types FC, SC, ST, LC, MU.