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How Do Fused Fiber Optic Couplers Work?

Fiber optic couplers are a critical component of fiber optic communication systems and networks. They allow two or more fiber optic cables to be connected, as well as split and combine signals. In this blog post, we will discuss how these devices work and their various benefits.

We will also explore the different types of optical fused couplers and when they should be used. By the end of this post, you will have a better understanding of how fused fiber optic couplers work and why they are so useful.

What are Fused Fiber Optic Couplers?

Optical fused couplers are special components used to join two optical fibers together, allowing for the transfer of data. In most cases, these couplers are made from fiber-reinforced plastic (FRP) and feature a small glass window, which is sealed with an adhesive.

Fused fiber optic couplers are an important component in optical communication networks, providing a way to connect two fibers or split a single fiber into multiple fibers. They are used in a variety of industries, including telecommunications, medical imaging, and data centers.

At the most basic level, a fused fiber optic coupler consists of two fibers that are connected together. The two fibers are heated and fused together, forming a single fiber optic connector. The fused connector has multiple channels, which allow light to pass from one fiber to the other.

What are the benefits?

There are several advantages of using fused fiber optic couplers over other types of connectors.

  • They offer superior performance and reliability due to their low insertion loss and return loss. They offer high flexibility and scalability, allowing you to expand your system with additional connections as needed.
  • Furthermore, because fused fiber optic couplers are so durable, they can stand up to extreme temperatures, as well as shock and vibration. This ensures that your connection remains consistent even when faced with challenging environmental conditions.
  • Additionally, these couplers are designed to be low maintenance, requiring minimal upkeep over their long lifespan. This makes them a cost-effective option for businesses looking to optimize their networks.
  • Finally, due to their small size and light weight, they are perfect for applications where space is at a premium, such as in mobile or satellite communications.
  • For these reasons, fused fiber optic couplers can be an ideal choice for businesses seeking to take advantage of the latest in communication technology. They offer a reliable, cost-effective solution that can help ensure smooth and consistent data transmission in any environment

How do they work?

Fused fiber optic couplers are an important component in modern fiber optic communication systems. They are used to connect two or more optical fibers together, allowing them to transmit data simultaneously over a single transmission line.

The fibers are fused together using heat, which creates a strong connection that can last for many years. This type of coupling is widely used in both commercial and military applications.

Optical fused couplers work by allowing light from one fiber to travel through another. The coupling is created when two fibers are heated and then fused together.

As the fibers fuse, their cores become permanently linked, forming a secure and reliable connection between the two. The resulting connection allows data to travel between the two fibers, as well as be transmitted through multiple connected fibers.

Importance and Primary Uses of PM Fiber Components 

When we talk about technology, it’s advancing with time and people are enjoying its benefits. In the list of technologies, one promising option that has been introduced many years ago is PM fiber components. From the time the technology has been introduced, it is being used widely, covering almost every industry. And the wide use of these components has influenced manufacturers to come up with many more advanced components. 

Primary uses of PM fiber components

Primarily, these components are used in communication. The introduction of PM fiber components has revolutionized the efficiency and bandwidth of the conventional communication medium. The components are much faster than the conventional medium, offering better performance in the organization. They are said to be the backbone of the communication industry. 

Other than this, the PM fiber components are widely used in the entertainment industry. They are basically used for optical illusion. As the technology is quite basic, everyone can afford it. You will understand the importance of these components only after using them. 

In the industrial sector, the applications of PM fiber components depend on the need. Just keep in mind that the cost and hassle of using components in a smaller office are minimal compared to a larger office. 

What are the common PM fiber components?

  • Multimode/single mode couplers/taps- It’s a component that provides optical signal splitting while preserving polarization with a high extinction ratio. 
  • Splitters- This component is used to split the signal power transmitted to the element’s input. 
  • Isolators – A component that reduces back reflections in optical fibers and backscattering of light. 
  • Wavelength Division Multiplexers- This component enables the use of multiple light wavelengths and sends data over the same medium. 

Other than these common PM fiber components, there are many more on the list. But, others are used depending on the application requirements. 

Every PM fiber component comes with unique features. It’s not easy for a layman to decide the right uses for these components. So, we recommend you connect with a person who is knowledgeable about the subject and possess the necessary skills. 

How are 125um and 80um PM Fiber Components different?

Discussion about PM fiber components is incomplete without mentioning 125um and 80um PM Fiber Components. These two are the commonly used components. 

Traditionally, 125um PM fiber components were in the picture. But, today, 80um PM Fiber Components are trending and there are many strong reasons for the same. 

The thin diameter of 80um PM Fiber Components has characteristics, such as no tension fused taper, online adjustment of main axes in polarization fibers, and high stability package. The performance of both the components is the same, but 80um offers low bend loss at small bend diameters. 

The 80um PM Fiber Components help users to reduce package sizes significantly, meeting the demands of all current and future applications. 

PM fiber components are important, especially in the communication and entertainment industry. If you belong to any of these industries, look for the right manufacturer of these components. 

What are PM optical components? What are their types?

PM components are some of the most useful micro-optical parts used in a wide range of applications. They are used in a variety of industries, from medical to aerospace, data center to telecommunication, and defense to biomedical, and must meet strict quality standards.

What is a PM Component?

A PM Optical Component is a type of optical component that is designed to do a specific function while maintaining the function of light. These components are made from materials such as glass or plastic and are used in a variety of applications, such as telecommunications, data transmission, fiber lasers, fiber amplifiers, instrumentation, testing, and more.

What are the uses of PM optical components?

PM optical components are used in a variety of applications, from medical devices to telecommunications. They are often used in high-speed data transmission and fiber optic communication systems.

PM components can be used to create a variety of different optical fiber designs, including single-mode and multimode fibers. They can also be used to create bend-insensitive fibers, which are ideal for use in tight spaces or areas with limited access.

In addition to creating fiber communication networks and modifying traditional data transmission networks, PM optical components can also be used in medical devices. They are often used in conjunction with other imaging modalities.

What are the different types of PM optical components?

There are various types of PM components available for a variety of applications. Some of the most important PM optical components are:

  • PM inline polarizer – Available in a wide range of operating wavelengths, a PM inline polarizer is designed to allow light transmission with one specific polarization while blocking other polarization. It can convert non-polarized light into polarized light and is widely used to enhance the extinction ratio of signals with excellent polarization properties.
  • PM isolator – It is a polarization-maintaining fiber optic component designed to pass the light in one direction and eliminate the back reflection and scattering in the reverse direction. It is mainly used for the prevention of optical feedback and o protect the fiber optic systems from damage caused by optical feedback.
  • PM Circulator – It is a small yet high-performance fiber optic component that routes signals from port 1 to port 2 and incoming port 2 signals to port 3, where port 3 signals can either be absorbed if they are unwanted or used if you need a full circulator.
  • PM Filter WDM – This small fiber optic component is used to multiplex PM light signals and maintain the output polarization with a high extinction ratio by employing the latest micro-optic filter technology. It is often available in two variants called PM Filter CWDM and PM Filter DWDM.
  • PM Fused Coupler – This optical coupler made from standard fused PM fiber is designed to split or combine high-power linearly polarized light into two paths or one, respectively, without interfering with other wavelengths used along and perturbing the state of polarization.

Do you need 1.0μm PM components, 2.0μm PM components, or 80μm PM Fiber Components for your project or application? Please connect with DK Photonics.

Everything You Need to Know about WDM Technology in Brief

The WDM technology is booming and being used at a large scale and help you tackle multiple networking challenges. But how does it work? What are CWDM and DWDM? What does PM Filter WDM mean? We will learn all about these things in this article.

What is WDM?

Wavelength Division Multiplexing (WDM) is an optical transport technology that enables you to divide existing optical fibers into multiple channels of traffic so that several streams of data can be transported simultaneously.

Think of WDM as creating multiple lanes on a highway so that the traffic flows efficiently.

Due to the potential multiple benefits, such as efficient transfer of more data, less time, cost-effectiveness, and easy usage, more public sector organizations, healthcare providers, utility providers, financial institutions, corporate enterprises, data center operators, and telecommunication companies are considering implementing WDM technology.

How does WDM technology work?

In WDM networks, light signals or wavelengths of multiple colors are used over the same optical fiber. Optical transmitters that are tuned to specific wavelengths are used to send light into a passive combiner called a multiplexer (Mux).

All of the wavelengths selected for data transmission travel along a common path i.e. an optical fiber and then they are separated by using a passive optical splitter or demultiplexer (Demux).

WDM networks are usually bi-directional and allow combined and split wavelengths to travel in both directions over a single fiber.

 WDM technologies such as Demux and Mux allow organizations to place the device at either end of a fiber pair and combine multiple wavelength channels into a single fiber pair instead of using different optical fiber pairs.

What are CWDM and DWDM?

Coarse Wavelength Division Multiplexing (CWDM) and Dense Wavelength Division Multiplexing (DWDM) are the two fundamental technologies built based on WDM technology. However, both of them have different wavelength patterns and are used for different applications. Both WDM technologies can effectively increase the bandwidth capacity needs and maximize the use of both existing and new fiber components and fibers.

The main difference is that CWDM systems support eight wavelengths per fiber and are used for short-range communication, DWDM systems support 96 or more channels spaced at 0.8nm apart within the 1550nm C-Band spectrum. Therefore, when compared to CWDM, DWDM systems can transfer a huge quantity of data through a single fiber link.

What is PM Filter WDM (FWDM)?

PM Filter WDM is the technology that wavelength division multiplexing while maintaining the polarization of the light signal. Based on environmentally stable thin film filter technology, PM Filter WDM is characterized by wide-band, high extinction ratio, low insertion loss, and high return loss. PM Filter WDM is ideal for PM fiber amplifiers, fiber lasers, and instrumentation applications.

At DK Photonics, we provide high-quality and affordable PM filter WDM, DWDM, and CWDM in a range of standard and custom specifications. For any queries, please get in touch with us.

How to Understand a Polarizing Beam Splitter’s Design?

As one of the common optical devices, polarizing beam splitters are used to split a single light beam into two beams of varying linear polarization. The devices are useful for splitting high-intensity light beams like lasers. They are very different from absorptive polarizers as they don’t absorb or dissipate the energy of the rejected polarization state. 

The polarizing beam splitter plays an important role in the optical world, including telecommunication. But, people using them don’t understand their design. They don’t know how the polarizing beam splitter works. 

To understand the design of polarizing beam splitters, there are apps and software available in the market. But, they don’t give much clarity. 

In this post, we will try to explain the design of the polarizing beam splitter so that you can use the device in the right way and make the most out of it. 

The design of the polarizing beam splitter

The most common design configuration of the polarizing beam splitter is in the form of a cube. The cube design is more valuable than the plate design of the polarizing beam splitter. And there are many reasons for the same. 

In the cube configuration of the polarizing beam splitter, there is only one reflecting surface. One reflecting surface of the cube configuration avoids producing ghost images. Also, the translation of the transmitted output beam is quite small compared to the input beam. The small output beam simplifies the process of aligning optical systems. 

A closer look at the cube configuration of the polarizing beam splitter is different and complicated. You should read slowly and try to understand all the parts and elements. 

A closer look at the cube configuration explained:

The cube configuration of a polarizing beam splitter comprises two prisms, which are positioned at right angles. One prism includes a dielectric coating evaporated on the intermediate hypotenuse surface. 

The polarizing beam splitter starts functioning when the light wave enters the cube. As soon as the light wave enters, the coating transmits the portion of the incident wave with the electric field, which is polarized in the plane of incidence and reflects the portion of the incident wave with an electric field that is orthogonal to the plane of incidence. Typically, the experts represent these parts of incident waves by p-polarization and s-polarization. 

Use of cube-designed polarizing beam splitters 

Due to the dielectric coating, the cube-designed polarizing beam splitters are useful for broadband or tunable sources and selected laser lines. It’s because the dielectric coating can be designed as spectrally broadband or narrowband. 

Other than this, these coatings are used in high-power laser applications that feature very large damage thresholds. 

Conclusion 

To achieve optimal performance of the polarizing beam splitter, you should study its design and make modifications wherever and whenever required. For this, you can seek help from professionals as well. 

What is Active/Passive DWDM Mux/Demux?

Before we discuss anything, you need to understand what DWDM technology is. Dense Wavelength Division Multiplexing or DWDM combines a set of optical wavelengths, transmitting with one fiber. As a laser technology, DWDM increases bandwidth on existing fiber-optic backbones. Most importantly, DWDM technology enables optic fiber networks to transmit signals of several wavelengths simultaneously.

The DWDM system has two indispensable modules; Mux and Demux. Together it’s referred to as DWDM Mux/Demux. Mux is at the transmitter end, bringing several data signals together for transporting over a single fiber. On the other hand, Demux, at the receiver end, separates the signals coming together and passing each channel to an optical receiver. 

When combined, the DWDM Mux/Demux multiplexes multiple DWDM channels into one or two fibers, extending the bandwidth of optical communication networks with low cost and long transmission distance. This is what a ideal solution of the model is.

About Active/Passive DWDM Mux?Demux

Based on the device’s need for power supply, the DWDM is divided into active DWDM Mux/Demux and passive DWDM Mux/Demux. If it’s active DWDM Mux/Demux, it means the device needs a power supply. 

Difference

An active DWDM Mux/Demux consists of a wavelength adjustable laser, wavelength-adjustable filter, wavelength-selective amplifier, etc. With this, you get more control over your optical network. The best part is that you can dynamically re-tune wavelengths without dropping connections. Commonly, the active DWDM Mux/Demux is used in large-capacity optical transmission applications. 

On the other hand, passive DWDM Mux/Demux is unpowered, pure optical equipment. Unlike active DWDM Mux/Demux, the passive DWDM Mux/Demux requires zero maintenance, upgrades, or electricity to function properly. It consists of a dispersion device, interference device, optical coupler, etc. Comparatively, passive DWDM Mux/Demux is simple and convenient to use as it is a plug-and-play system, which is mainly applied to the access layer of MAN, campus network, enterprise network as well as various special industry networks, including banking, public, security, etc. In the present situation, it’s widely used in optical fiber communication solutions. 

The only thing is that passive DWDM Mux/Demux doesn’t have OAM, meaning there is no protection in case of link failure. But, fortunately, there is another type of DWDM Mux/Demux to solve this problem. 

This type adds optical switches, optical splitters, and other devices in an optical fiber link based on the passive DWDM Mux/Demux. When power is ON, the third type is used as an active DWDM Mux/Demux to monitor each port in real-time. On the other hand, when the power is off, the device is used as a passive DWDM Mux/Demux without affecting the link transmission. In simple words, the third type combines the advantages of active and passive DWDM Mux/Demux, solving the shortcomings of the passive option. No matter what, it’s difficult to manage and maintain this problem through the intervention of active equipment. 

This is how active and passive DWDM Mux/Demux is different. When you buy them, keep this difference in your mind. 

Difference between CWDM and DWDM Mux/Demux devices

With the advent of big data, organizations need highly efficient and capable data transmission speed. And it has been possible with CWDM and DWDM Mux Demux devices. These technologies can transport an extremely large capacity of data traffic in telecom networks. It’s said that the technologies can easily deal with the bandwidth explosion from the access network.

The only problem with organizations is which device to choose. They are very confused between CWDM and DWDM Mux Demux devices. To make the selection easier, we will discuss the differences between these two devices. But before that, we will discuss CWDM and DWDM technology along with Mux and Demux. 

About CWDM and DWDM technology 

These are two types of wavelength division multiplexing or WDM that solve increasing bandwidth capacity needs. They are specifically designed to tackle different network challenges. 

Coarse Wavelength Division Multiplexing or CWDM technology supports eight wavelengths per fiber and is designed for short-range communications. The technology uses wide-range frequencies with wavelengths spread far apart. 

The cost of CWDM is generally low with a lower capacity of sub-10G and shorter distance applications where cost is an important factor. Compared to DWDM, CWDM supports less capacity of links as well as distance. It’s capable of transporting up to 10 Gigabit Ethernet and 16G Fiber Channel. 

On the other hand, Dense Wavelength Division Multiplexing DWDM uses tighter wavelength spacing to fit more channels onto a single fiber, compared to CWDM. In this, the number of multiplexed channels is much denser. As the DWDM system supports 96 channels spaced 0.8 nm apart, it transmits a huge quantity of data through a single fiber link. 

DWDM systems can carry high amounts of data across long distances spanning up to hundreds or thousands of kilometers. 

About Mux and Demux

Mux or multiplexer combines multiple signals over a channel in the form of a single complex signal. This process is known as multiplexing. In other words, the multiplexing process transmits various digital input signals, analog signals, or streams of data over a single channel, integrating various low-speed channels into high-speed ones for the transmission process. 

On the other hand, Demux works in a reverse manner to the Mux. The process is known as demultiplexing. In this technique, a demultiplexer acts as a combinational circuit, accepting only one data input but directing through various outputs. In other words, demultiplexing reconverts a signal back into its unrelated and separate signals.

Difference between CWDM and DWDM Mux Demux devices

The major difference between CWDM and DWDM Mux Demux devices is the number of channels and ports. 

  • CWDM can have 18 channels but DWDM can have up to 96 channels 
  • CWDM is available in 8 and 16-port models but the common configurations of DWDM are 4,8,16 and 32. 

Though there are only two differences between CWDM and DWDM Mux Demux devices, these differences matter. So, you should choose wisely when you go to buy a DWDM Mux/Demux device and a CWDM Mux/Demux device.

What is the working of single-mode fused couplers?

Fused couplers are one of the most important optical passive components used in fiber optic communication systems. The reason why they are used is that they allow you to do light branching and splitting in passive networks.

These passive components are made by joining two separate optical fibers that work on the principle of coupling between parallel optical waveguides. Their claddings are fused over a small area. In addition to light branching and splitting, fused couplers are also used in various other applications, such as:

  • Wavelength multiplexing or de-multiplexing
  • Filtering
  • Polarization selective splitting
  • Wavelength-independent splitting and more

These components work on the principle of energy transfer between optical fiber cores after fusion.

What are Single Mode Fused Couplers?

The most basic form of a fused coupler is a 2×2 waveguide directional coupler made by placing parallel single-mode optical waveguides. Hence, this type of coupler is commonly called a single-mode fused coupler. Sometimes, this component also represents which fibers it is made of. For instance, a 2.0μm single-mode fused coupler clearly indicates it is made using 2.0μm single-mode fibers.

How do Single Mode Fused Couplers work?

The primary operation of this device involves a complete or partial transfer of optical power between two wavelengths. The transfer of optical power occurs because of the optical coupling between the evanescent tail of one waveguide’s guided mode in which light is launched and that of the natural mode of the second waveguide. You can think of this optical interaction as the beating between symmetric and asymmetric super mode.

An important role in the coupling process is also played by the parallel interaction region, which has a longitudinally constant structure.

As soon as the light is launched into one of the waveguides and it is coupled into one of the waveguides, it excites a linear combination of both types of modes. Since each mode has a different propagation constant, the fields propagating in the system also develop a relative phase difference between the distance of propagation.

When the accumulated phase difference between the two modes over a certain length becomes pi (π), the superposition of both modal fields cancels the field amplitudes in the input waveguide and an addition in the second waveguide. This is referred to as coupled state and the associated interaction length is called coupling length.

When the interaction length extends beyond the coupling length, then reverse coupling occurs and for propagation over double coupling length, there develops a phase difference of 2π. As a result, optical power is restored in the input waveguide. This happens periodically across the entire time of wavelength of propagation.

If both waveguides are identical, there can occur a transfer of complete optical power. However, if both waveguides are non-identical, only a certain amount of maximum power transfer can take place.

At DK Photonics, we manufacture a wide range of fused couplers, including 2.0μm single-mode fused couplers, 1.0μm single-mode fused couplers, 1XN single-mode coupler modules, and more. We also offer customization of single-mode fused couplers. If have any queries related to single-mode fused couplers, please get in touch with us.

What’s the Future of Polarization-maintaining (PM) Components?

PM components are ruling the world. Be it any industry, different types of PM components are widely used, especially in telecommunication. And it’s because of the name but the features and characteristics that PM components have. They work easier, increasing performance and productivity significantly. But, many individuals and business owners are doubtful about the future of PM components. They think it’s just a matter of a year or two and then, things will become like before. Or, something new will come into the market replacing PM components. 

In this post, we will discuss future aspects of PM components. We will discuss if PM components will stay in the market or be replaced by any other component. 

Which market will increase the demand for PM components in the future?

The fiber optic market is competitive and expected to be more competitive. According to a report, the projected growth of the fiber optic market is 10.9% CAGR from 2022 to 2027. 

The factors driving this growth are growing internet penetration and data traffic, the rising number of data center facilities worldwide, and the mounting demand for high bandwidth. 

With the growth in fiber optics, demand for PM components will undoubtedly increase. Not one or two, but every PM component will be in demand, playing crucial roles in the fiber optic market. 

You might not believe this too soon now as the circumstances are not favorable. But, soon after the year 2022, you will find lots of changes in the market and demand for PM components. 

Other things that will contribute to the increasing demand for the PM components 

End users’ demands of performance and reliability of their fiber optic networks increase the use of PM components. Keeping aside everything, these two factors matter a lot. PM components, no matter who the manufacturer, ensure performance and reliability. And this is something end users won’t compromise with, today, tomorrow, or in the future. 

This will keep the demand for PM components stable like today or increase in the future. There will be no decreasing scale for PM components ever. 

Other than this, the customization of PM components will rule the market. Yes, you read it right; customization with PM components. Years ago, manufacturers followed a standard protocol to manufacture PM components, which was not feasible for all industries. But, today manufacturers are offering product customization. They are more responsive regarding individual client needs with issues such as repair and calibration. 

Due to product customization, there has been a huge improvement in the productivity and performance of the industries using PM components. End users are getting what exactly they want without compromising on anything. And this is going to increase in the future as users are happy with customization.  

By now, you might have understood that PM components are not going anywhere. They will strongly rule the market now and forever. So, connect with one of the best PM component manufacturers to fulfill your needs. 

DK Photonics is one name in China that manufactures PM components, including 1.0μm PM Components based on standard and custom specifications. The company offers optical couplers, optical isolators, optical splitters, pump combiners, optical circulators, fused products, WDM and Filter products, high-power PM components, and more. 

What is a pump and signal combiner used for?

Pump and signal combiners are being used in a wide range of applications, such as fiber laser and amplifier, telecommunication in industrial and biomedical areas, metrology, life science, imaging, quantum optics, and more.

To better understand a pump and signal combiner, you need to learn about pump combiners.

What is a Pump Combiner?

A pump combiner is originally a fiber-optic coupler designed to send pump and signal light into a fiber laser or fiber amplifier. It also goes by another name called pump couplers.

Certain fiber optic devices such as high-power fiber lasers and amplifiers are based on rare-earth doped double-clad fibers. In such devices, you can inject pump and signal light into such a fiber by simply focusing the light onto a bare fiber end.

The same thing is done for fiber amplifiers and fiber laser devices in the research stage. Industrial lasers are best if they are an all-fiber setup, where fiber-coupled pump laser diodes are directly connected to the active fiber via some passive transmission fibers, avoiding any air spaces in the path of the light signal.

When using multimode optic fibers, one needs fiber-optic pump combiners as they facilitate better robustness and stability of devices.

Some pump combiners can safely handle multiple kilowatts such as 10W or 30W, and they are called high-power pump combiners.

What is a pump and signal combiner?

A pump and signal combiner has two interfaces. On one interface, a fiber can be connected to a certain type of active fiber directly by using the fusion-splicing technique. Sometimes, there is an additional passive fiber between these two fibers to include a fiber Bragg grating if that cannot be written into an active fiber.

On the other interface, the combiner has several input multimode fibers that can be connected to fiber-coupled pump laser diodes. In addition, there is another single-mode fiber or a few-mode fiber for injection or extraction of the signal light. Though no signal light needs to be injected in the the case of a fiber laser, laser light needs to be extracted from one end.

Thus, when a pump combiner also has an additional fiber for signal light extraction or injection, it is referred to as a pump and signal combiner.

An (N+1) x1 pump and signal combiner can combine or couple N pump lasers and 1 signal channel into one fiber and create a high-power pump laser source.

What are the uses of pump-and-signal combiners?

The applications of pump and signal combiners have become very diverse and seeing even more expansion. Some of the most important uses and applications of pump and signal combiners are:

  • Pumping of fiber lasers and amplifiers
  • Pumping of fibers with multiple cores and large mode areas
  • Pump combiner for elements Nd, & Yb,  & Er & Ho & Tm-fiber
  • Metrology
  • Life science
  • Quantum optics
  • Gravitational wave detection – Atom cooling and trapping
  • Imaging
  • Industrial telecommunication
  • Biomedical and more

To buy top-quality and affordable pump and signal combiners, please contact DK Photonics.