Fiber optical couplers are used to both split and combine optical signals in optical fibers. As passive optical components, they are often used in data transmission.
The optical frequency multiplexing method, wavelength division multiplexing (WDM), splits the wavelengths in such a way that each spectral color has its own transmission channel.
Active fiber-optical components are available for multi-mode and single-mode fibers.
These components are used for fiber-optical data transmission in communication applications. Isolators allow light to pass through the fiber in only one direction; circulators are non-reciprocal elements.
Attenuators are used to reduce the power of signals when the receiver is near the sender or the signal being sent is too strong, either of which would result in the receiver being overloaded.
