An optical splitter, also called a fiber optic coupler, splits an optical signal into multiple parts. It's a simple but effective way to distribute one input signal to various outputs without losing signal quality. Its primary role is in Passive Optical Networks (PON), which are the foundation of. Fiber optic splitter, also referred to as optical splitter, fiber splitter or beam splitter, is an integrated waveguide 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. “Passive” means it needs no electricity. One large pipe brings water into a building.