The short answer: A 1×2 splitter introduces ~3. In fiber optic networks, particularly in FTTx (Fiber to the x) and PON (Passive Optical Networks) deployments, splitters play a central role in distributing the optical signal from a single source to multiple destinations. These are known as passive optical splitters, and they perform the function. A fiber optic splitter, also known as a beam splitter, is based on a quartz substrate of an integrated waveguide optical power distribution device. That email is why every FTTH engineer needs a reliable loss chart pinned to their desk — and why I built this one.