Month: December 2018

Optical Circulators and Its Passive Optical Components

To fulfill the requirement of communication efficiency, network technicians generally use optical circulator in a fiber optic system as it reduces the loss of light. An optical circulator is a small yet powerful device used in optical communication systems. The device is typically used to separate optical signals that (in an optical fiber) travel in opposite directions.

Functioning Principle and Components

Optical circulators usually consist of a polarizing beam splitter, Faraday rotator, reflector prism, birefringent blocks, and a retardation plate. The functioning of an optical circulator is a little similar to optical isolator. A light which travels in one direction right through the Faraday rotator will have its polarization rotated in one specific direction. A light that enters the rotator from the opposite direction will have its phases rotated in the opposite direction (sometimes may depend upon the propagation direction of the light).

In other words, light always rotates in one direction in accordance with the rotator regardless of its traveling direction.

Three-port optical circulator is widely used so let’s discuss that first. A signal in a three-port optical circulator is transmitted from 1st port to 2nd port where another signal is transmitted from 2nd to 3rd and additionally, a third signal can also be transmitted from 3rd to 1st.

Types

As per the Polarization Characteristics

If we talk about the characteristics based on the optical circulator’s polarization capabilities, they can be divided into two major types:

PM – Polarization Maintaining

PI – Polarization Insensitive

Each PM optical circulator typically comes in the market with a polarization maintaining fiber which makes it an ideal component for applications where it is necessary to maintain polarization, for example, Raman pump applications, 40Gbps systems, etc.

Polarization insensitive optical circulator is a small lightwave component which delivers high-performance functioning. The component comes in the market having features like low insertion loss, high isolation, high stability and reliability, and low polarization-dependent loss (PDL).

It is high in demand in combination with fiber gratings and other reflective components in close-packed wavelength-division multiplexing (DWDM) systems, high-speed systems and bi-direction communication systems.

As per the number of ports availability

Optical circulators fall into three main types when it comes to the number of ports:

3-port

4-port

6-port

3-port and 4-port optical circulators are commonly used way more than the 6-port optical circulations. In such circulators, optical light that is transmitted from any port can easily be redirected to any other port, regardless of the port-type.

An optical circulator is very commonly applied in a long list of applications within a fiber communication system. In modern optical communication systems, the optical circulator is usually used for wavelength division multiplexing networks, optical time domain reflectometers, fiber amplifier systems, bi-directional transmissions, etc.

With primary characteristics such as high isolation, low crosstalk, low insertion loss, and large bandwidth, the optical circulator can also become an in-built component of the same device as transmitters, amplifiers, and receivers.

Achieving highly precise polarization is Easy like Never Before with Insensitive Optical Circulator

There are applications like optical fiber communication networks, fiber optic instruments, and depression compression modules wherein it is vitally important to polarize the lights going in multiple directions into one single direction. Thanks to Insensitive Optical Circulator, it is now pretty possible to achieve the polarization of light into single direction.

Optical circulator is specially designed fiber optic device with an ability to separate optical power traveling in opposite directions in one optical fiber. The optical circulator can also be used to achieve bi-directional transmission over a single fiber. The high isolation between the input and reflected optical power and low insertion loss makes the circulator highly suitable for the use in advanced communication systems and fiber-optical sensor systems.

Besides being highly capable of controlling the light flowing into different directions and directing it into a single desired direction, the insensitive optical circulators have hosts of other qualities that make it much the best choice for fiber optic device. They are:

  • Low insertion loss
  • High isolation
  • Ultra-low PDL and PMD
  • Epoxy-free optical path
  • Special operating wavelengths

The optic circulator provides high reliability and excellent optical performance. The device’s high isolation properties make it ideal for applications in telecommunications, fiber optic sensing, bio-medical, and photonics research.

The circulators com with different ports, for example three or four ports that cover standard wavelength rang. Also, it is possible to customize the wavelength according to different needs. For example, you can get circulators with wavelength ranges such as 1030nm, 1040nm, and 1050nm.

There are various brands making insensitive optical circulators. This means there are a wide range of makes of such optic devices available in the market. They all have features that almost identical but this does not mean they also have the same performance. The process they are built and quality of the material used is factors that play a vital role in the performance of an optic circulator. In addition, other things that should be considered before making the final buying decision are like:

  • Rugged, compact design: Rugged, encased design utilizing bulkhead connectors rather than loose pigtails reduces the fragility of the fibers from tangle and handling.
  • That is easy to install or mount: Choose the one that is easy to mount with optical cables. Four strong magnets hold the rugged package securely onto steel surfaces.
  • Pigtail circulators for the applications that require a length of fiber on the input and output of the circulator.
  • And the price of the circulator

DK Photonics Technology Limited is a leading and one of the top companies providing high quality optical passive components that are widely used for telecommunication fiber sensor and fiber laser applications. If you are looking for quality insensitive optical circulators for the most reasonable price, you can count on DK Photonics Technology Limited.

Things That You Must Know about Polarization Maintaining Optical Circulator

Optical fiber is used for an electric device in which light polarization is required. And each fiber is designed to do a certain job and so is suitable for some certain applications. So you should have the knowledge of an optical fiber that you want to buy and make sure the fiber you want to buy would be perfect for your need. So we have gathered some crucial information about optical circulator used for maintaining light polarization, and that will help you choose the right fiber.

If you are looking for a circulator for devices like fiber amplifiers, fiber sensors, test and measurement appliances, coherent detecting appliances, The 1310nm&1550nm 3-port Polarization Maintaining Optical Circulator with both axis working would be the best choice. The circulator is compact and very efficient to route the incoming signals from Port 1 to Port 2, and incoming Port 2 signals to Port 3. The circulator works as a single that can be used to transmit light from an input fiber to an output fiber. It directs the light returning from the output fiber to the third port. The 3 port circulator with both axis working is like an isolator that protects the input fiber from return power but the light that is rejected can be used.

Another fiber can be also used for those applications is 3 port optic circulator with fast axis blocked. This type of circulator is also lightweight, compact and performs well. This circulator also works as the circulator (with both axis working) does. Both circulators used for maintaining polarization can handle the power ranging from 300mW to 20 W, and have center operating wavelengths ranging from 850nm to 1650nm.

Both optical circulators (with both axis working and with fast axis blocked) provide a host of benefits such as low insertion loss, high isolations, etc. Here are some key benefits that the circulator provides:

  • Low Insertion Loss
  • High Isolation
  • High Extinction Ratio
  • Low Cost
  • High Stability & Reliability

Apart from those two circulators that are widely used for a wide range of applications, there are other optical fibers that are used for electric devices. Whatever fiber you buy make sure it works perfectly with your device.

So before you start looking for optical fibers, get to know about your device in details. Learn everything that can help you in a way or so to decide on which type of optic fiber you should look for.

Once you are done with the type of fiber you need, find a Polarization Maintaining Optical Circulator supplier. There are many Polarization Maintaining Optical Circulator suppliers in China, you should trust only those that are reputed and have long been into the business.