Optical fiber coupler have the same functionality as electronic couplers: The signal is split into multiple points(devices). For tapping (monitoring the signal quality) or more complex telecommunication systems, fiber optic couplers are required which need more than simple point-to-point connections, such as ring architectures, bus architectures, and star architectures.
Passive couplers and active couplers
Fiber optic couplers are either active or passive devices. Between active and passive couplers the major difference is that a passive coupler without optical-to-electrical conversion redistributes the optical signal. Active couplers are electronic devices that split or combine the signal electrically and they make use of fiber optic detectors and sources for input and output.
Electronic couplers are easy to make because as long as you have physical contact between the conductor’s there is the flow of electric current. Fiber optic coupler types are defined by their input and output port numbers. They are designed to fulfill different applications.
wavelength-selective couplers
Wavelength selective couplers are WDM (wavelength division multiplexer). fiber splitter split the signal, not based on their power but rather based on their wavelengths.
Tree couplers
Tree couplers make use of only one input and split it into multiple (more than two) outputs. As a combiner, you can use tree couplers as backward (bidirectional). Multiple output signals (now function as the input actually) are then combined to a single input (now as the output actually).
Star couplers
From tree couplers, star couplers are very much different as they have multiple inputs and multiple outputs. The fibers then radiate from the central point like a star.
T couplers are also called Y couplers which are based on their look. T couplers are three-port devices with one input and two output ports.
Manufacturing technologies of Fiber optic coupler
For fiber optic coupler there are majorly three types of manufacturing technologies: micro-optics, fused-fiber, and planar waveguide.
Individual optic elements such as lens, prism, mirrors, etc. are used by micro-optics technologies to construct an optical route that functions as a coupler. This is quite an expensive approach and not as popular as the other two types. Fuse- fiber coupler makes use of the most basic material - optical fibers.
Original source: https://fibermart.blogspot.com/
