Fiber optic coupler is one type of fiber optic component that allows for the redistribution of optical signals. Thorlabs offers a varied selection of single mode (SM), polarization-maintaining (PM), multimode (MM), and double-clad fiber couplers, as well as 1x8 and 1x16 SM PLC splitters; 1x4, 1x8, and 1x16 PM PLC splitters; wideband multimode circulators; RGB combiners; and WDMs.