Category: Tap Coupler

What Factors Affect the Performance of Polarization Maintaining Tap Couplers?

A Polarization Maintaining Tap Coupler is a special device used in fiber optic systems. It helps split or combine light signals while making sure the light stays in its original state, called polarization. But there are several things that can make a Polarization Maintaining Tap Coupler work better or worse. What are these factors that affect the performance of polarization maintaining tap couplers? Let’s take a look at seven of these important factors.

But before we begin, let us look at how these Polarization Maintaining Tap Couplers work.

How Do Polarization Maintaining Tap Couplers Work?

Polarization Maintaining Tap Couplers are made up of special fibers that have a unique structure that allows them to maintain the polarization of the light passing through them.

When light enters the coupler, it is split or combined while preserving its polarization state. This is important for applications where the polarization of the light signal needs to be maintained, such as in fiber optic sensors or specialized communication systems.

The Type of Fiber Used

Polarization Maintaining Tap Couplers are made with special fibers that can keep the light in its polarized state. If the fiber isn’t the right type or if it’s not of good quality, the coupler might not be able to keep the light polarized properly.

How It Is Manufactured

Polarization Maintaining Tap Couplers are carefully put together using special techniques. If there are any mistakes or problems during the making process, it can cause issues like too much light being lost or the polarization not being maintained well.

How Much Light It Splits or Combines

The coupler needs to split or combine the right amount of light for what it’s being used for. If it’s splitting or combining too much or too little light, it won’t work as well as it should.

The Environment Around It

Factors like temperature, humidity, and vibrations can affect how well a Polarization Maintaining Tap Coupler works. Very hot or cold temperatures, or too much moisture in the air, can make the fibers inside the coupler change shape a little bit, which can mess up the polarization. Vibrations can also cause problems.

How It Is Packaged or Protected

The way the Polarization Maintaining Tap Coupler is packaged and protected can also make a difference. If the packaging isn’t good enough, it might not protect the coupler from factors like temperature changes or vibrations, which can make it not work as well.

How It Is Connected to Other Parts

In many fiber optic systems, the Polarization Maintaining Tap Coupler needs to be connected to other parts. If these connections aren’t done correctly, it can cause problems like the fibers getting misaligned or stressed, which can affect how well the coupler maintains polarization and sends light.

The Coupling Ratio

The coupling ratio is how much light the coupler splits or combines. Different uses might need different coupling ratios. If the ratio isn’t right for what the coupler is being used for, it might not work as well as it should.

In order to ensure that Polarization Maintaining Tap Couplers function as best they can, engineers and technicians should try to understand these seven important factors. They can choose the right fibers, make the couplers carefully, pick the right coupling ratio, protect them from factors  like temperature changes and vibrations, package them properly, connect them correctly, and more.

Why Should Polarization Maintaining Filter Coupler Feature High Extinction Ratio?

A polarization maintaining filter coupler splits the light from an input PM fiber between 2 output PM fibers or combines light signals from 2 input fibers into a single PM output. Basically, the device is used to split high-power linearly polarized light into multiple paths without perturbing the linear state of polarization or SOP. Other than this, the device is used as a power tap to monitor signal power in a PM fiber system without disturbing the linear SOP of the light propagating in the PM filter. 

In the applications, you will find PM fiber interferometers, power sharing in polarization-sensitive systems, and signal monitoring in PM fiber systems. The package consists of rugged stainless steel, which is designed for high optical performance and stability. 

The polarization maintaining filter coupler features low excess insertion loss, low back reflection, and high extinction ratio. 

In this post, we will discuss one of the features of polarization maintaining filter coupler i.e. the extinction ratio, and why it should be high. 

Extinction ratio 

The extinction ratio quantifies the cross-coupling in regards to birefringent fiber. It indicates the amount of light that can mix between the two polarization axes. The value of the extinction ratio is important because it measures the polarization maintaining the performance of an optical fiber. 

Mostly, the extinction ratio is misunderstood by many people, leading to lots of problems in the future. 

The value of the extinction ratio depends on the length of the fiber and the environmental conditions in which you use it. If the fiber is subject to high mechanical stress and small-diameter bends, then internal disruption is possible, reducing the extinction ratio significantly. 

What’s the impact of extinction ratio on the system performance and other parameters?

With a high extinction ratio, the bit-error ratio or BER improves. And when the bit-error ratio improves, it reduces the number of errors and the amount of error correction required. The high data rates are pushed through materials, loss, and dispersion close the eye and errors increase. 

What happens if the extinction ratio is low or poor?

If the extinction ratio is low or poor, the polarization-maintaining filter coupler will increase its power penalty (PP), worsen its Bit-error ratio (BER) and diminish its benefit of increased power. 

When does the extinction ratio become significant?

If you want quality and successful performance of the maintaining polarization filter coupler, the extinction ratio becomes significant. 

Sometimes, the measured values between manufacturers and designers are very different. Even the end users obtain different values than the manufacturers. If this happens, the device will be rarely productive. So, the value of the extinction ratio should be determined before buying a polarization-maintaining filter coupler. And undoubtedly, it should be high. 

Polarization Maintaining Tap Coupler: Features & Major Applications

The polarization maintaining (PM) tap coupler basically provides optical signal splitting with tap ratio while also preserving the exact state of polarization. By combining the PM collimators and thin-film filter technology, the polarization maintaining coupler features high return loss, low insertion loss, environmental stability, and high extinction ratio.

The PM tap coupler splits the light coming from the input PM fiber into two outputs PM fibers. The polarization state further can be aligned with the fast axis or the slow axis of the polarization maintaining fibers. The stainless steel and rugged tap coupler are mainly designed for stability as well as high optical performance. The device with split ratios from 1 to 50% is now available so you can utilize it accordingly to your needs.

Some major applications of polarization maintaining tap coupler:

There are various applications of PM tap coupler, among which the major ones include:

  • Monitoring signal in polarization maintaining fiber systems
  • Fiber sensors
  • Helps in power-sharing of polarization-sensitive devices and systems
  • Polarization maintaining interferometers
  • Fiber optic devices and instruments
  • Coherent detection

Polarization maintaining tap couplers are made of separate crystals of lights and the output port of lights emitted is different from the polarization filter coupler. The coupling ratio is more accurate, while it can also handle high power as compared to the PM filter couplers.

On the other hand, the PM couplers can also be used to split high power linearly polarized light into different paths and that too without disturbing the state of polarization (SOP). Furthermore, it can even be used as a power tap for monitoring the signal power in the PM fiber system that functions without perturbing the linear state of polarization (SOP) of light in the polarization maintaining fiber.

Features of polarization maintaining tap coupler:

Some of the major features of PM tap couplers include:

  • Low insertion loss
  • Compact inline package device
  • High stability power
  • Can handle high energy and power
  • The optimum optical performance in a different environment
  • Excellent credibility
  • High extinction ratio
  • Accurate tap ratio
  • Accurate coupling ratio

So, these are a few primary features and applications of polarization maintaining tap couplers that you must be aware of. Besides, if you have the requirement of this device or any other type of PM coupler with tailored specifications then you may simply talk to PM coupler manufacturers and get the best assistance for the same. Just be sure to consult the right manufacturer so you can be confident that you are investing your money and time on the right device and at the right place.

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

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.