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What is a Fiber Collimator? Why is it needed?

Tell us the name of one common thing that you can find in various high-power components such as high-power optical isolators, fiber circulators, fiber optic attenuators, and CWDM/DWDM modules. All these components have one thing in common and that is called a high-power fiber collimator. In this blog, we will discuss high-power collimators in brief. So, if you want to know what these are and why they are needed, keep reading till the end.

What is a fiber collimator?

The meaning of the term “collimate” means to make light rays accurately parallel. Hence, a fiber collimator is a fiber optic component that is used to help change the diverging light from a point source into a parallel beam.

In other words, a fiber collimator is a simple module that consists of fiber and a lens and its basic function is to produce parallel beams.  

Fiber collimators are used to collimate the light at the fiber end and can also be used to couple light beams between two fibers. During the designing process of fiber collimators, utmost attention is given to the accurate adjustment of the fiber and lens so that parallel beams can be obtained.

Another thing you need to know is that the stronger the signal strength the higher the efficiency of the fiber collimator. And the fiber collimators that can handle a huge amount of power are categorized as high-power components.

An efficiently designed high-power collimator is characterized by low insertion loss, high-power handling capability, excellent temperature stability, and small beam convergence. Hence, it is considered an ultra-reliable device.

What is the need for fiber collimators?

In fiber optics applications, it is often necessary to transform the light output from an optical fiber into a collimated beam. For that, a simple collimation lens is considered sufficient. But the end of the fiber must be firmly fixed at a distance from the lens that is usually equal to the focal length. Thus, to make this more convenient in practice, a fiber collimator is used in fiber optics applications that require a collimated beam.

Fiber collimators can also be used for launching light from a collimated beam into a fiber or for fiber-to-fiber coupling where light from the first fiber is collimated and then focused into the second fiber by another collimator.

Another application of fiber collimators is the combination with a back-reflecting mirror and an additional element to achieve desired effects. For instance, you can insert a Faraday rotator to obtain a Fiberized Faraday mirror.

Other major applications of high-power fiber collimators are fiber lasers, fiber amplifiers, instrumentation, and test and measurement.

The Difference Between Active and Passive Optical Networks

In the optical network transmission process, we usually see the conversion of the electrical and optical signal at the input and output ports using a wide range of active and passive components. The light source is the foundation of optical fiber networks, and all the network transmission is always done in the form of light signals at input and output ports. It is why optical network engineers require active and passive components to design optical networks for accurate and efficient signal transmission and communication.

An optical network can either be an active optical network or a passive optical network, depending on the type and performance of the source signal. The active optical access network primarily employs Active Ethernet technology for point-to-point direct and single fiber bi-directional access, which improves bandwidth but with increased costs. As a result, passive optical access technology (PON) gradually took over the active optical networks to design cost-effective networks for light signal transmission.

What is Active Optical Network (AON)?

AON (Active Optical Network) refers to a network in which the signal is transmitted using a photoelectric conversion device, active optical components, and fiber optics. Optical lasers, optical amplifiers, optical transceivers, optical receivers, and other optical components are included in optical assemblies. The AON is a type of network that enables point-to-multipoint optical communication for a variety of industrial applications such as optical fiber transmission lines and optical remote terminals.

Features of AON Networks

  • Large transmission capacity
  • Long transmission distance without a repeater 
  • Mature technology 

What is Passive Optical Network (PON)?

Passive Optical Network (PON) refers to an optical distribution network (ODN) that doesn’t use any active devices or components for its operations. It includes optical passive components such as optical couplers, optical connectors, optical attenuators, optical isolators, optical circulators, optical switches, and so on in its building blocks. The Passive Optical Network (PON) is designed as an access network for optical fiber applications because it doesn’t use any active component that requires a power source to function. 

Features of PON Networks

  • Large transmission capacity
  • Long transmission distance
  • Low cost 
  • Excellent performance and scalability
  • High reliability
  • Great transparency of business

PON allows point-to-multipoint access network and fiber transmission at high security and low cost. Fast network construction is another advantage of a passive optical network over an active network. It is the most widely used optical network across industries as it is more convenient to scale and upgrade using optical passive components in comparison to AON technologies.

What is the Role of Optical Passive Components in Fiber Networks?

Did you know that tolerances tighten and margins for error shrink as operators send fiber deeper into their networks for higher speed and capacity?

That means quality is crucial, and every network component must improve its performance.

Let’s examine what fiber optical passive components are and how they can help service providers increase speed and bandwidth.

We’ll also look at how these devices can improve the delivery of high-quality, high-speed broadband to many subscribers.

  1. Multiplexers

Optical signals travel from the headend to the transition point or directly to the subscriber via wavelengths.

A multiplexer combines these wavelengths onto one fiber to travel the distance. They are then demultiplexed near the destination and separated.

  • Wavelength Division Multiplexing (WDM)

WDM is a technology that combines and transmits many wavelengths on a single cable. Depending on the number of channels to be multiplexed, WDM can be employed in several different ways.

The advantage of WDM is that it is less complex and inexpensive to implement, allowing for higher speeds and bandwidth capacity without requiring any additional fibers.

  • Coarse Wave Division Multiplexing (CWDM)

CWDM can fit up to 18 channels on a single fiber while maintaining a 20 nm channel space. Due to its lower cost, CWDM is a more cost-effective alternative to complex dense wave division multiplexing (DWDM) architectures.

Low-density, short-run situations are ideal for CWDM. It’s also appropriate for networks with no plans to expand in the future.

  • Dense Wave Division Multiplexing (DWDM)

When capacity and reach are crucial, DWDM is the best option. To increase the capacity of fibers, DWDM enables a significant number of channels in a smaller band.

DWDM C-band channels are capable of reaching distances of over 40 kilometers.

The strict tolerances of DWDM necessitate the employment of complex transceivers and very sensitive filters and prisms in the passive devices; therefore, installations are often more expensive than CWDM.

  • Band Wavelength Division Multiplexing (BWDM)

BWDM modules combine groups of wavelengths onto a single optical fiber. A BWDM divides groups of channels rather than single channels and is particularly well suited to MDU or business park applications where there are often more dense groupings of customers.

  • Optical Add Drop Multiplexing (OADM)

The OADMs operate by deleting and rerouting certain wavelengths for specific destinations as the remaining signals proceed down the trunk.

OADMs are excellent when dedicated wavelengths are required to service enterprises or clusters of subscribers.

  • Optical Splitters

By dividing the signal symmetrically into 2, 4, 8, 16, 32, 64, or 128 divisions, operators can share the cost of expensive optical components among a significant number of customers.

In line with the optical link budget, these divisions can also be cascaded to divide the number of splits into smaller, optimum serving areas.

Optical splitters are often employed to extend optical signals to customer residences in FTTx, and passive optical networks (PONs) are implemented at the headend/central office and the outside plant.

Optical splitters come in a variety of shapes and sizes, depending on the application.

Optical passive components are essential for a network’s efficient and cost-effective operation. Working with a professional can assist you in optimizing your optical networks to get the most out of your fiber infrastructure.

Applications of optical passive components

A passive optical network is a multi-premises point-to-multipoint network design that enables the providers of communication services to serve several consumers via the same connection. During the activities, no active components are required for conversion of electrical-to-optical or optical-to-electrical. There are a variety of optical passive components available in the market which include optical switches, optical isolators, optical couplers, optical circulators, optical connectors, optical splitters, optical filters, optical, and optical add/drop multiplexers. Optical passive components are found to be a viable answer for today’s telecommunication requirements.

But how are these optical passive components applied? Well, there are various applications of optical passive components. We have listed down the most common types of optical passive components and their application:

Optical coupler/splitter 

The most common optical passive components used for multi-demultiplexing of the wavelength of optical signals are optical couplers/splitters. Optical splitters are utilized for splitting the light signals in multiple fibres whereas optical are meant for integrating the signals arrived from various fibers. The optical coupler and optical splitter are quite similar types of optical passive components. However, the basic difference in their functionality depends on the requirement of the connection and the end-use of the component in input or output. 

Optical connector 

Optical connectors, also known as fiber optic connectors, are generally used to link two optical fibers, cables, or devices temporarily. Manufacturers have developed a variety of optical connectors in optical passive components to fulfill a variety of communication requirements. LC, FC, SC, ST and MTRJ styles of connections are the most common types of optical connectors. 

Optical filter 

An optical filter is a device used for multiplexing/demultiplexing the wavelength with a thin dielectric layer that allows the user to add or subtract a specified wavelength throughout fiber communication. It is mostly used for filtering out a particular wavelength in the middle of fiber according to preset parameters.

We now have a quick and efficient way of data transport due to optical fiber networking. To achieve optimum durability, efficiency, and monetary effectiveness in an optical network, a variety of optical components are used. Optical passive components play a critical role in establishing successful fiber connections.

Optical Attenuator

Optical Attenuator is a term used to describe a device that reduces the intensity of light transmitted. It is employed in the following situations:

  • Keep receivers from being saturated.
  • Ensure that wavelength intensity is balanced.
  • Equalize the strength of the nodes.

There are majorly four types of optical attenuators available in the market for balancing power in fiber communication, named fixed attenuators, variable attenuators, in-line attenuators, and plug-in attenuators.  

Optical switch 

These are devices used for governing the connection between ports meant for output and input. They’re mostly used for:

  • Remote monitoring of an optical fiber network
  • Multiplexing transplantation
  • System for monitoring optical paths
  • Sensory system based on optical fibers
  • Testing of optical devices

Choose the best optical passive components for your fiber networks and ensure better results. 

What are Fiber Bragg grating sensors? What are their uses and applications?

Fiber Bragg Grating (FBG) based sensors are one of the most popular optical fiber sensors these days because they are quite easy to install, don’t get influenced by electromagnetic interferences, and can work well even in highly explosive atmospheres. In this blog, we will walk you through what Fiber Bragg grating-based sensors mean and what uses and applications the FBG-based sensors have.

What are Fiber Bragg grating sensors?

Fiber Bragg grating is a small-size optical fiber that consists of a pattern of many reflection points that reflect particular wavelengths in the direction of the light origin and transmit all others. Based on the principle of Bragg diffraction, it is a progressive optical passive component that looks like a normal optical fiber but acts as a sensor that converts energy from mechanical into optical and electrical.                                                                                                                                                                        

FBG sensors are simple optical sensing elements that can be photo-imprinted in optical fibers. These are wavelength modulated sensors that help detect physical parameters such as strain, temperature, pressure, humidity, vibration, and others depending on the changes in the wavelength.

What makes FBG sensors better than their counterparts?

FBG sensors come with many features and qualities that one can’t get from ordinary optical sensors. Some of these are:

  • High sensing capability
  • High stability and reliability
  • Energy-efficient and cost-effective
  • Easy installation and customized length
  • Immunity to electromagnetic interferences
  • Immunity to radio frequency interferences
  • Suitable for highly explosive environments

What is the use of Fiber Bragg Grating sensors?

  • Fiber Bragg grating sensors can be used as inline optical fibers to block certain wavelengths. Apart from this, they can also be used as wavelength-specific reflectors.
  • Since FBG sensors are ideal wavelength-selective components, they can be used where detection of multiple sensing parameters is required.
  • FBG sensors are also widely used for monitoring composites that are subjected to impact.
  • These optical sensors can help measure the internal strain of the host by evaluating the shift in the reflective wave peak’s wavelength.
  • FBG-based sensors when located even too close to impact site can detect residual strains from an impact that C-scan and visual inspection fail to detect.
  • An array of embedded FBG sensors can predict the location of damage as well.
  • FBG sensors are also used for vibration sensing when they are placed intimately in contact with the vibrating object.
  • BG sensors can also help in acoustic sensing of ultrasonic waves not only in bulk materials but also in liquids.
  • These optical sensors have also been used for monitoring ultrasound in vivo.
  • Femtosecond laser-imprinted FBGs are thermally stable, and, thus, are potential candidates for high-temperature sensing applications.
  • These sensors can also be used for intelligent textiles as they can be integrated into flexible orthoses to determine a patient’s requirements and generate feedback.

What are the applications of Fiber Bragg Grating (FBG) sensors?

FBG sensors are the optical passive components that have so much potential to be used in a myriad of applications across different industries. While some applications are widely common, many areas remain yet to be explored when it comes to utilizing the powerful capabilities of FBG sensors.  Some of the common applications of FBG sensors include:

  • ASE filtering
  • Wavelength filtering
  • Environmental monitoring
  • Power line monitoring
  • Structural health monitoring
  • Instrumentation applications, such as seismology
  • Pressure sensors for extreme environments
  • Downhole sensors in oil and gas wells to measure the effects of temperature, external pressure, seismic vibrations, and inline flow measurement

Most FBG sensors are used in single-mode fibers and their modeling is relatively simple. When buying FBG sensors online, do your research properly as FBG sensors are available in a variety of options, and picking the right one is important to achieve the desired performance and functionality.

Do parasitic signals affect the performance of pump laser diodes?

Parasitic signals are usually undesirable elements and most often unavoidable too. When parasitic elements are encountered in sensitive components like pump laser diodes, you need to take precautions to get rid of these parasitic signals. Otherwise, parasitic signals can lead to crosstalk, interference, and unreliable operation. That’s where pump laser protectors come into the picture.     

Why do we need to protect the pump laser from parasitic signals?

Pump lasers and pump laser diodes are the components that require having high reliability. However, if we keep allowing parasitic signals to reflect into the laser, it can lead to errors, performance degradation, and unstable operation. Therefore, pump laser protectors play a great role in ensuring the safe and reliable operation of pump laser diodes.

Now, you must be wondering what exactly pump laser protectors are. Let’s find out.

What are pump laser protectors?

Pump laser protectors are passive components that are specifically designed to protect the laser’s center wavelength by preventing parasitic signals from being reflected back in the laser. Besides, they also allow maximum transmission from discrete pump laser diodes that are fiber-coupled. Since pump laser protectors filter out parasitic signals by blocking them, these passive components are also known as pump laser filters.

What are the applications of pump laser protectors?

Pump laser protectors find their use in a variety of applications, such as:

  • Fiber amplifiers: Can be used with fiber amplifiers that are used to boost optical signals directly without converting them into electrical signals.
  • Fiber laser: Can be utilized with solid-state type laser that utilizes optical fiber as the gain medium and is widely used for material processing, telecommunication, etc.
  • Testing: It is not easy to distinguish the effects of parasitic signals, which made it many times difficult to measure the performance of certain fiber optic components. Pump laser protectors can help with testing.
  • Instrumentation: Can help achieve a high signal to noise ratio

What Properties Do Pump Laser Protectors Have?

When buying pump laser protectors, you should verify if they:

  • Have low insertion loss
  • Can handle high power
  • Offer high isolation
  • Are highly reliable
  • Have excellent temperature stability
  • Are highly affordable

Where Can I Buy High-Quality Pump Laser Protectors (Filters)?

If you are looking to buy high-quality pump laser protectors, look no further than DK Photonics. We can provide you with pump laser protectors in different specifications. Even if you can’t find pump laser protectors with the specifications you are looking for, you can place a custom order and we will facilitate you with it. All you need is to contact us and share your custom specifications.  

What does polarization refer to in polarization maintaining components?

In polarization maintaining components, there is a huge rule of polarization as it influences the performance of these components, the quality of the signal transmitted across the network, and their desirability in certain applications. So, if you wonder about what this polarization means in optical fiber communication networks, this blog is a must-read for you.

What is the meaning of polarization in optical fiber communication?

A light beam is composed of two electrical vector field components that are orthogonal to each other. These components vary in terms of frequency and amplitude. We call a light beam polarized when these two components vary in amplitude (or phase).

Polarization in optical fibers has been extensively researched and studied, and now, we have a variety of ways to either minimize this polarization or maximize it to take advantage of polarization, depending on our requirements.

Meaning, in polarization maintaining components, components are designed using optical fibers to maintain polarization to take advantage of this phenomenon.

When talking about polarization, there is another term that you should know about for better understanding.

Birefringence

This phenomenon occurs in certain types of materials that can split a light beam into two different paths. It happens because these materials have different indices of refraction based on the polarization direction of the light. This phenomenon is also seen in optical fibers because of the slight asymmetry in the cross-section of the fiber core and external stresses exerted on fiber due to bending. In general, birefringence is induced more often by external stresses than the geometry of the fiber.

A specialty fiber that maintains polarization creates a consistent birefringence pattern along its length intentionally, and thereby prevents the coupling between two orthogonal polarization patterns. In any fiber design, the geometry of the fiber and materials used in the formation of fiber creates a lot of stress in one direction and hence produces higher birefringence as compared to the random one.

In the market, a number of designs with stress-inducing architectures, such as Panda and Bow Tie PM Fibers with different cut-off wavelengths are available for commercial use.  

Did you know polarization is characterized by some measurable properties? We have enlisted some of these properties below:

  • Extinction Ratio: It is expressed in dB and refers to the ratio of minimum polarized power and maximum polarized power.
  • Polarization Dependent Loss: Also expressed in dB, it is the maximum peak-to-peak variation in insertion loss.
  • Polarization Mode Dispersion: It is another form of material dispersion.

Since the fiber core is not perfectly circular in general and it is exposed to mechanical stresses that induce birefringence in the fiber, it causes one of the orthogonal polarization modes to travel faster than the other. This, in turn, causes dispersion of the optical pulse.

The maximum difference in the times of the mode propagation caused by dispersion is known as differential group delay, which is typically expressed in picoseconds.

Fundamental Things You Need To Know About Passive Electronic Components!!

Regardless of whether you know it or not, one of the crucial factors that distinguish kinds of electronic components from one other is if they are active or passive. Although, tons of individuals are still unsure about the difference! On the off chance, if you also fall under the same category of individuals, there is nothing to feel embarrassed as we have got you covered.

Mentioned below is the difference between active and passive components. So, keep reading.

The Difference

Active components: These are crucial parts of a circuit that entirely depends on an external power source to manage or modify electric signals. For your better understanding, active components such as transistors and silicon-controlled rectifiers (SCRs) utilize electricity to handle electricity.

Passive components: High power components such as resistors, transformers, and diodes do not consume external power source to function precisely. These high power components utilize some different properties to manage the electrical signal, as an outcome, they only need the current going via the connected circuit. Resistors hinder the flow of electrons without transferring more electricity into the system. The two precisely explained high power components examples are listed below.

1. Capacitors: A capacitor also called as condenser is a passive two-terminal electronic component that is utilized for storing energy electro-statically in an electric field.  There are various forms of practical capacitors, yet each and every one still contain at least two electrical conductors that are separated by an insulator aka dielectric. The conductors can be in the form of thin films, sintered beads of metal, foils or conductive electrolyte. The non-conducting insulators are used to double the charge capacity of condenser. An insulator can be made of glass, ceramic, plastic film, air, vacuum, paper, mica, oxide layer etc. In plenty of electrical devices, capacitors/ condensers are widely used as parts of electrical circuits. Unlike a resistor, an optimal condenser does not squander energy. Rather than dissipating, a capacitor stores energy in the state of electrostatic field between its plates.

2. Resistors: A resistor is a passive two-terminal electrical component that applies electrical intransigence as a circuit element. Resistors are generally used to lessen the current flow, and, at the same time, they are also used for lowering the voltage levels within circuits. In electronic circuits, there are utilized to restrict current flow, adjust signal levels, bias active elements, terminate transmission lines and the list is endless. High-power resistors that are capable of dissipating loads of watts of electrical power can also be used as part of motor controls, in power distribution systems, or as test loads for generators. In addition to this, resistors may comes with fixed resistances that only get changed with a cold temperature, time or operating voltage. Also, variable resistors can be used to adjust circuit elements.

So, these were some of the most imperative things that you should know. For any further clarification and information, please get in touch with us whenever you want.

What is Wavelength-Division Multiplexing and Its Benefits?

A technical solution that permits the combination (“mux”) of several separate light wavelengths (signals/channels) from different lasers on a single fiber utilizing a passive component for transmission to another site is called Wavelength-division Multiplexing (WDM).

The WDM components then demultiplex the combined wavelengths at the receiving location and route them to their appropriate receivers.

The Main Components of WDM System

In a WDM system, there are two different types of approaches:

  • Dual-fiber unidirectional transmission
  • Single-fiber bidirectional transmission.

The simultaneous transmission of multiple optical channels on a fiber propagating in one direction is known as dual-fiber Unidirectional WDM.

There are separate wavelengths that convey different paths across an optical fiber. At the transmitting end, these signals are combined for transmission across the fiber and demultiplexed to complete multiple paths at the receiving end.

It is necessary to use a second optical fiber for the opposite direction of the transmission. And since the transmission takes place in both directions, it is vital to use two optical fibers.

Bidirectional WDM is the simultaneous transmission of optical channels in both directions on a fiber, with the wavelengths employed segregated to achieve full-duplex communication between the two sides.

The standard components of a WDM system are:

  • The network management system
  • Optical transmitter
  • Optical relay amplifier
  • Optical receiver
  • Optical monitoring channel are.

The WDM system’s overall structure

Transceivers, WDM wavelength division multiplexers, patch cords, and dark fiber components make up the basic WDM system.

WDM system

The multiplexer and demultiplexer are critical components in the WDM technology, and their performance is crucial for the system’s transmission quality.

What are the benefits of using WDM Technology?

  1. Large Capacity

WDM’s main advantage is that it can fully utilize the optical fiber’s bandwidth resources and enhance data transmission capacity without requiring changes to the current network architecture. It allows an optical fiber’s transmission capacity to multiply a single wavelength.

2. Excellent Compatibility

WDM has a wide range of signal compatibility. Each wavelength is independent of the others and does not interfere with each other when transmitting signals with diverse qualities such as pictures, data, and sound to ensure transmission transparency.

3. Flexibility, Cost-effectiveness, and Dependability

WDM technology enables the addition of new channels as needed without disrupting the existing network, making upgrades convenient.

There is no need to replace the optical cable line when updating or increasing the network. New enterprises can be added or superimposed by adding wavelengths.

Large-capacity long-distance transmission can conserve optical fibers and 3R regenerators, lowering transmission costs dramatically.

4. Wavelength Routing

WDM is one of the most critical technologies for implementing all-optical networks. The up/down and cross-connection of various telecommunication services can be implemented by altering and adjusting the wavelength of the optical signal on the optical path.

A reputable designer and manufacturer of high-quality optical passive components can provide a comprehensive portfolio of WDM solutions tailored to your unique needs, allowing you to achieve system goals in the most efficient way possible.

Understanding PM Optical Isolators: Some Important Applications

Optical reflection is one of the few significant causes of performance degradation in amplifiers and fiber lasers. However, this significant issue can easily be dealt with by using high-quality optical isolators. For those of you who are not familiar with these devices, an optical isolator may be defined as a small device that are designed and created to transmit optical signals in a single direction. Now, this particular device tends to come in two different versions – polarization-insensitive optical isolators and polarization-maintaining optical isolators.

Although both of these versions of optical isolators are effective enough to block any returning light, the insertion loss in a polarization-maintaining optical isolator tends to depend on the input polarization. In this blog, we will shed some light on this particular version of optical isolators.

About Polarization Maintaining (PM) Optical Isolators

Polarization maintaining optical isolators (PM optical isolators) are known to be not just simpler but also very compact when it comes to their design, making them highly suitable for polarization maintaining fiber applications. This type of optical isolator is also highly useful in certain scenarios where an input free space beam of constant polarization tends to pass across the Faraday optics. In both of these applications, the linearly polarized beam that comes from the source is aligned with the transmission axis of the optical isolator.

Even though you can find several types of optical isolators in the market such as fiber-embedded isolators, all-fiber isolators, fiber Faraday rotator isolators, and many others, the core of a commercially available optical isolator tends to consist of a Faraday rotator and a couple of birefringent crystals.

What are the applications of Polarization Maintaining Optical Isolators?

Polarization-maintaining optical isolators have been gaining more and more prominence with each passing day due to the important role they play in modern transmission systems and fiber optic systems. The following are some of the most significant applications of PM optical isolators.

  • One of the main applications of PM optical isolators is that they are useful in applications that are sensitive to unwanted optical reflections and need the presence of polarized light. Since the fact that even a low optical reflection can be enough to increase the laser phase noise, wavelength stability, and intensity noise, the use of PM optical isolators tends to become inevitable in such applications.
  • Polarization maintaining optical isolators are also used in telecommunications and other similar areas such as the likes of biotechnology and sensing such as fiber-optic gyros. Not only this, PM optical isolators can also be seen extensively used in various other applications including fiber amplifiers, fiber sensors, fiber lasers, and so on and so forth.

These were just some of the many applications of polarization-maintaining optical isolators. So, now that you have gained enough knowledge about these devices, you would be able to make the right decision for your particular requirements. However, you must ensure that you deal with a reliable and highly reputed service provider in order to reap all the benefits.