In this guide, we'll break down what fiber splitters do, how they work, and how to choose the best model for your application. It enables one signal source (OLT) to serve multiple. A fiber optic splitter is a passive optical component that divides a single incoming optical signal into two or more outgoing signals, or combines multiple incoming signals into one. Unlike active devices (which require power), splitters operate without electricity, relying solely on the physics of. A splitter is not a filter like a wavelength division multiplexer (WDM). Typically, but not always, there is one input in and multiple outputs.