Fiber optic splitters, also referred to as optical splitter, or beam splitter, is an integrated wave guide optical power distribution device that can split an incident light beam into two or more light beams, and vice versa, containing multiple input and output ends. Optical splitter has played an important role in passive optical networks (like EPON, GPON, BPON, FTTX, FTTH, etc.) by allowing a single PON interface to be shared among many subscribers.

Specifically speaking, the passive optical splitter can split, or separate, an incident light beam into several light beams at a certain ratio. The 1×4 split configuration presented below is the basic structure: separating an incident light beam from a single input fiber cable into four light beams and transmitting them through four individual output fiber cables. For instance, if the input fiber optic cable carries 1000 Mbps bandwidth, each user at the end of output fiber cables can use the network with 250 Mbps bandwidth.