Let us make a brief introduction for optical fiber splitters and optical insertion loss：
Definition Of Fiber Optical Splitters
Optical insertion loss
The optical fiber splitter is the component with the largest attenuation in a PON system. The optical insertion loss is the loss of an optical signal resulting from the insertion of the component such as connector or splice in an optical fiber system. In order to conserve the power budget of a PON system, It is necessary to minimize the insertion loss from the splitter.
Optical fiber coupler loss chart：
Fiber Optic Splitter Loss Table Chart For FTB And PLC Type：