What is a fiber optic coupler?
A coupler is an optical device that combines or splits signals travelling on optical fibers. A port is an input or output point for light; a coupler is a multiport device. A coupler is passive and bidirectional. Because the coupler is not a perfect device, excess losses can occur. These losses within fibers are internal to the coupler and occur from scattering, absorption, reflections, misalignments, and poor isolation. Excess loss does not include losses from connectors attaching fibers to the ports. Further, since most couplers contain an optical fiber at each port, additional loss can occur because of diameter and NA mismatches between the coupler port and the attached fiber. Couplers and Fiber Optic Networks A coupler is a device that will divide light from one fiber into several fibers or, conversely, will couple light from several fibers in to one. Important application areas for couplers are in networks, especially local area networks (LANs), and in wavelength-division multiplex
