Want to Know What a PM Tap Coupler is? Read this

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 Instead of diving straight into
complexities of polarization
maintaining tap coupler, let’s first discuss what an optical coupler
simply is. An optical coupler is a device which can join one or more optic
fiber ends for transmitting light waves in multiple paths. It is capable of
combining two or more inputs into a single output as well as dividing a single
input into two or more outputs. If you compare it with a splice or a connector,
you will find that with an optical coupler, the signals can be more attenuated
as the input signal can be distributed among the output ports.

 

In general, fiber optic couplers can be
divided into two categories: active and passive.

 

For active coupler, an external energy
source is required. On the other hand, there is no requirement of power to
operate passive couplers.

 

In the market, you will find different
types of fiber optical couplers such as X coupler, combiner, splitter, stars
and trees. This categorization is carried out on the basis of the number of
input and output ports.

 

As the name implies, a combiner does the
work of combining two signals and providing a single output. Similarly, a
splitter does the functioning of dividing a single optical signal to facilitate
two output signals. It can further be divided into Y couplers and T couplers.
If we talk about star couplers, they distribute power from inputs to outputs.
While some tree couplers take multiple input signals and provide one output
signal, others take a single input and provide multiple output signals.

 

Fiber optic couplers are manufactured using
a variety of technologies such as planar waveguide, fused-fiber and micro
optics.

 

Now, let’s move to polarization maintaining
optical couplers. They are the micro optic filter type devices which facilitate
optical signal splitting while maintaining polarization with high extinction
ratio. Being a coupler in the essence, they are capable of either splitting the
light from an input polarization maintaining fiber between two output PM fibers
or can join signals from two PM input fibers into a single PM output fiber.

 

By now, it is clear that what fiber optical
couplers and PM optical couplers are. So, what exactly is a polarization
maintaining tap coupler? It is a type of PM coupler which can split light waves
with accurate tap ratio.

 

The polarization state can be aligned
either with slow axis or fast axis of the polarization maintaining fibers. It
is made from separate light crystals and the output port is also different from
PM filter coupler. The benefit of using a PM tap coupler is that it can handle
higher power and also has more precise coupling ratio than PM filter coupler.
So, PM tap coupler is a better device with high optical performance and
stability to be used for splitting high power linearly polarized light wave to provide
multiple outputs while still preserving the polarization state.

 

This tap coupler can also be used as a
power tap in a PM fiber system to monitor signal power without disturbing
polarization state of the light traveling in PM fiber.

 

Applications of PM Tap Coupler

 

Power sharing in polarization sensitive
systems

PM fiber interferometers

Signal monitoring in PM fiber systems

Coherent detection

Fiber optic instruments

Fiber sensors

Features of PM Tap Coupler

 

Compact-in-line package

Low insertion loss

High extinction ratio

Excellent reliability

Superior stability

Optimum optical performance

Accurate tap ratio

Can handle higher power

Precise coupling ratio

If you have requirement of polarization
maintaining tap couplers or another kind of PM coupler with custom
specifications, contact one of the esteemed PM coupler manufacturers so that
you can be sure of that you are investing your time and money at the right
place.