Month: March 2019

Functions of a Cladding Power Stripper and Its Market

The configuration of a particular DCFLS (double cladding fiber laser system) is generally schematically arranged. The fiber is cladding-pumped by high power diode stacks which then spread and amplify the pump light. High reflector and output coupler fiber Bragg gratings are usually etched on the fiber. It is best for a system that has all light signals transmit in the core and inner cladding where all pumping light is core-absorbed.

But, there always some unwanted light exists in reality. CPS, also known as cladding power stripper is an important component of the fiber optic systems which is used to remove this typical unwanted light and distribute the heat, initiated by that unwanted light.

The unwanted light spreading all over the cladding actually consists of the main three parts mentioned below.

Amplified spontaneous emission (ASE)

Residual pump light at the gain fiber’s end

Core light getting leaked or reflected inside the cladding

Prior to the output of light, the unwanted light has to be eliminated so that it would use unused space optics of a complicated laser system. The unwanted light gets converted into heat and this heat may lead to heated up optics and the core light would not be able to focus nicely. Moreover, the heat may also burn or damage the system’s important components or deteriorate the function when multiple systems are combined together for greater efficiency.

In double cladding fiber laser systems, the unwanted optical power and light must be reduced so that the output light gains higher beam quality. Several kinds of research have been done to strip that light from the cladding. Removing the originally there fluoroacrylate jacket and coating the fiber with a high index polymer can literally strip residual light of more than a hundred watts. Fabrication using a suitable etching method successfully cleared the test and stated that it offers good behavior instability so that it can be used in the applications with higher power laser systems.

All such researches successfully eliminated the unwanted light and the crucial work after that light gets converted into heat. Some of the researches also provided a cooling method of their tests, including cooling water based plate and air cooling. But because the output power of DCFLS increases, the traditionally used cooling methods could not stand the harsh heat.

Apart from there functions, there are manufacturers who can provide you with cladding power stripper of all kind of double Clad fiber where cladding power can reach up to 500W. If you couldn’t find a standard CPS that fulfills your needs, you can provide your desired specification to a reliable manufacturer and get a quote for a custom CPS. Requests for custom fiber type, operation handling power operation, varying wavelengths, and other specific requirements will be addressed quickly.

How to Buy Optical Isolator: All You Need To Make the Right Decision

Isolators are crucial component used in optical communication applications to prevent unwanted back reflections. Most of isolators use faraday magnetooptic effect to polarize the light.  Choosing the right type seems to be important. And this is what we will be talking about through the blog. You will learn everything needed to make the right decision.

What is optical isolator?

According to Techopedia, “An optical isolator is a passive magneto-optic device that makes travel of light unidirectionally.”   The isolator which works on the principle of Faraday Effect is a wide range of communication applications to prevent unwanted feedback to the system.

Also, known by different names such as optoisolators, optocouplers and photocouplers, an optical isolator for polarization is made of different components such as a Faraday rotator with magnet, input polarizer and output polarizer.

The input polarizer which acts as a filter is meant to allow linearly polarized light into the rotator. The rotator then rotates the polarization of the input light by 45 degrees and is allowed to exit through the output polarizer. The energy is either absorbed or reflected depends on the polarizer type. There are two types of polarizer: high power and low-power polarizers.

Optical isolators are also grouped into tow two categories – polarization-dependent isolators and polarization-independent isolators.  The former uses input and output polarizers while the later uses input and output birefringent wedges. But both use a Faraday rotator.

Polarization sensitive Optical Isolators are used in a wide range of applications including laser applications where they are used to prevent unwanted feedback into the laser source. The use of isolators prevents the coherence of the laser from affective any damage to the diode itself. Because. The feedbacks it provides are capable of frequency shift, noise, mode hopping or amplitude fluctuation.

The isolators play a vital role in achieving stable laser diode operation. In high speed optical fiber transmittance amplifiers and routes, they are regarded as the most crucial device as they eliminate the adverse effect of return beams

Now you are far better equipped with the information you need to make a decision regarding the selection of isolator. There are many dealers that provide Polarization sensitive optical Isolators in China. But you should buy from the one that you think is reliable and that provides a better after sale support. You can also explore a variety of Polarization sensitive optical Isolators online.

A Brief Introduction to Polarization Maintaining Isolators and what’s Inside Them

Polarization maintaining isolator which ‘at times’ is also called fiber optic isolator and polarization maintaining optical isolator. It allows and keeps light to travel in one direction only. Its prime job is to prevent back reflection and backscattering in the reverse direction, for all states of polarization. In technical terms, the device is a two-port micro-optic isolator built with PM panda fiber. The isolator is commonly used in lasers, fiber optic systems, and amplifier systems. It actually prevents feedback which is not at all required in an optical oscillator.

Some devices in which this isolator is used

PM isolator is utilized all over the world majorly in communication systems, instrumentation applications, and polarization maintaining fiber-optic amplifiers. The isolator is also used in fiberoptic system testing and fiber-optic LAN system and CATV fiberoptic links.

Some of the many great features of these isolators

  • High isolation capacity
  • High Extinction Ratio
  • High Return Loss
  • Low Insertion Loss

Every fiber optic isolator has an optical fiber inside of it which is the most important component. Let’s now discuss how it works.

Optical fiber inside such isolators is a thin strand made of pure glass. It acts as a guide for the light wave over long distances by following the principle of ‘total internal reflection’. These are very effective when the light waves try to pass between two varying media.

The fiber inside these devices including polarization maintaining optical isolator is composed of two layers of glass – the core and the cladding. The core typically carries the actual signal of light and the glass layer surrounding the core is called cladding. In comparison to the core, the cladding has a lower refractive index. All of this causes total internal reflection successfully within the core.

What is transmitted over fiber?

Most fibers work in pairs where digital signals are encoded in light’s analog pulses preferably via the NRZ modulation – Non-Return to Zero. Since they operate in pairs, one is used to transmit while the other to receive, however, both signals can also be sent over a single stand.

Basic yet most used fiber types

  • SMF – Single Mode Fiber
  • MMF – Multi-Mode Fiber

The actual difference basically lies in the size of the core. SMF has an in-depth narrow core not more than 9µm which allows the propagation to just a single mode of light, whereas, MMF has a greatly wider core somewhere around 50µm and 62.5µm is also available on the market. MMF allows multiple modes of light to propagate. They both have their different characteristics along with their own pros & cons.

All about In-line Polarizer, Types, and Other Supportive Component

The in-line polarizer is a micro-optic device typically used to convert unpolarized light into polarized one including high extinction ration in the case. It is effectively used to enhance the signal’s extinction ration. A good quality in-line polarizer offers a high extinction ratio, high return loss, low insertion loss, and absolute environmental reliability and stability. It is ideally used in high-speed communication systems and applications like test instrumentation.

There’re two most common types of the in-line polarizer – Pigtail and No-tail.

Pigtail vs. No-tail:

In the pigtail version of the in-line polarizer, input/output fibers are attached to the package, whereas no-tail version often comes with two fiber connectors mounted straight on the package. No-tail version is best for applications where there’s no need for extra fiber length and a number of fiber jumpers/connections are already in the system.

The pigtailed polarizers are best used for fiber systems requiring optical components spliced to the networks or extra fiber is required to fill the gap between the lengths. This version of polarizer provides a great level of flexibility in device mounting and installation. The typical pigtail length is 1 to 2 meters on each side. The diameter of fiber buffer or jacket can be specified by an individual while discussing the requirements with an in-line polarizer manufacturer.

Pigtail fiber type

The pigtailed in-line polarizers have input/output fiber in three types of combinations:

  • SM/SM – Single mode to single mode
  • SM/PM – Single mode to polarization maintaining fiber
  • PM/PM – Polarization maintaining to polarization maintaining fiber

SM/SM fiber pigtailed polarizer works bi-directionally. The input and output ports are exchangeable except if the client determines a special combination of connectors.

SM/PM fiber pigtailed polarizer has the transmission hub of the polarizer adjusted to the slow axes of the polarization maintaining fiber. The output PM fiber is additionally keyed to the slow axes at the connector. Both the fibers are typically marked as ‘SM’ and ‘PM’ before shipment.

PM/PM fiber pigtailed in-line polarizer has (similar to SM/PM) polarizer transmission hub adjusted to the slow axes of both PM fibers. In spite of the fact that the PM/PM in-line polarizer is also bi-directional, it is often advised that client connects the device as indicated by the predetermined input and out directions in order to achieve the best extinction ration. They are also marked before shipment.

Fiber connectors

As per a client’s specification’s fiber connectors can either be SC/PC, FC/PC or FC/APC. Fiber connectors should always be cleaned with the help of fiber connector cleaning techniques followed as per the industry standard.

Following are some in-line polarizer applications

  • Fiber Amplifiers
  • Fiber lasers
  • Fiber Sensor
  • Test and Measurement
  • Communications System

Some of the top features which are common with every polarizer

  • Low Insertion Loss
  • High Power Handling
  • High Extinction Ratio
  • Low Cost
  • High Reliability

You can also add one or more features according to your requirements. In addition, it is advised to choose a trusted supplier who has been providing quality polarizers and other fiber optic products for a long time in your country.

Know about major uses and benefits of optical isolators!!

An optical isolator is mainly a passive magneto-optic device that makes the traveling of light unidirectional. The operation of the isolator is usually based on the Faraday Effect.

Optical Isolators can generally be categorized into two main polarizations including polarization-independent isolators as well as polarization-dependent isolators. While Polarization-dependent isolators utilize output and input polarizers along with a Faraday rotator, the Polarization-independent isolators use output and input birefringent wedges including a Faraday rotator.

Uses of Polarization Insensitive Optical Isolator   

Optical isolators are used in many applications, including laser applications where they are mainly utilized to prevent unwanted feedback into the laser source. This feature helps in not affecting the coherence of the laser while affecting any potential damage to the diode as the feedback is capable of frequency noise, shift, amplitude fluctuation or mode hopping.

Thus, it is one of the key devices in order to gain a stable laser diode operation. In situations where there are high-speed optical fiber transmittance amplifiers as well as routes, optical isolators are also considered indispensable devices due to their major capability of removing the adverse impact of return beams of light. They can also be called as photocouplers, optoisolators, and optocouplers.

Apart from these, there are many more uses of Polarization Isensitive Optical Isolators that makes them an important element for traveling the light from one direction to another.

Some of the major uses are provided below:

  1. They are used as a part of wavelength division multiplex systems (WDM), optical time area reflect meters, fiber intensification frameworks, and also as an important instrument for a test.
  2. Optical circulators are also largely utilized for converting or transforming the current unidirectional fiber optic communication link. They certainly change the communication link to a duplex link by installing the circulators at each finish of the polarization optical circulator.

Besides these important uses, the optical circulators also have several amazing benefits that make its utilization more important and necessary for traveling of light. The major benefits stated below are the ones that make the use of the optical circulators even more beneficial.

  1. Though the polarization Isensitive Optical Isolators are costly, they are more durable and reliable as compared to other circulators which are available in the market.
  2. Optical isolators are a good sensitive receiver and also they have better performance than the other ones.
  3. They are a better amplifier and are stronger than other isolators.
  4. When it comes to the final performance of optical circulators, polarization Isensitive optical isolators are far better and are more powerful in their workings.
  5. All the elements included in the optical isolators are aligned to a single platform that eliminates the use of several connectors and external ports.

Last but not least, you must also note that these isolators are the ones which are largely being accepted and used in various industries and streams.