A fiber optic coupler splits or joins light signals. It helps you control how data moves in optical networks. Think about how many ports you need. Know the difference between passive and active. Note that the term fiber coupler is used with two different meanings: It can be an optical fiber device with one or more input fibers and one or more output fibers. Light from an input fiber can appear at one or more outputs, with the power distribution potentially depending on the wavelength and. Fiber optic coupler is one type of fiber optic component that allows for the redistribution of optical signals. It covers a wide range of fiber optic devices such as optical splitters, optical combiners, and optical couplers.