The inherent advantages of light are doomed to play an important role in human history. With the booming of human technology, the development of optical fiber communication has made new progress. In the field of optical fiber communication, the most familiar thing for us should be fiber optic cable and patch cable. However, in addition to conventional fiber patch cable, there are some special kinds of fiber patch cable that we have never known. Today, let’s talk about a kind of special optical fiber patch cable: polarization maintaining fiber patch cable (PM Fiber).

Polarization Maintaining Fiber Patch Cable

What Are Polarization and Polarization Maintaining Fiber Cable?

If we want to understand PM fiber, we must first understand what polarized light is. Light is a kind of electromagnetic wave. It consists of an oscillating electrical field and a magnetic field. Its properties can be described by studying its electrical field, although we can also describe light and its effects in terms of magnetic field. Light waves can vibrate in many directions. When light vibrate in one direction, such as up and down in a single plane, they are called polarized light. When light vibrate in multiple directions, such as up/down and left/right, on more than one plane, they are called unpolarized light.

The polarization of light propagating in the fiber varies gradually in an uncontrolled (wavelength-dependent) manner, depending on its temperature and any bending of the fiber. Special optical fiber is needed to achieve optical performance, which is affected by the polarization of light passing through the optical fiber. Many systems such as fiber interferometers and sensors, fiber lasers and electro-optic modulators also suffer from polarization-dependent losses (PDL) that may affect system performance. In order to solve this problem, polarization maintaining fiber patch cable was developed. It is a special type of single mode optical fiber. Ordinary single mode optical fiber can carry random polarized light. However, the polarization maintaining fiber patch cable is designed to propagate only one polarization of the input light.

Types of Polarization Maintaining Fiber Patch Cable?

There are many kinds of polarization maintaining fiber patch cable, which support different data rates and are suitable for various connector types. According to different classification standards, polarization maintaining fiber patch cable can be classified into various types.

• Classified according to connector type – The ends of polarization maintaining fiber patch cable are sealed by optical fiber connectors. The connectors commonly used at both ends of PM fiber are FC, SC, LC and ST. Therefore, according to the connectors at both ends, there are many different types of PM fiber, such as LC-FC, SC-FC or FC-FC polarization maintaining fiber patch cables.
• Classified according to fiber type – PM fiber is made up of polarization maintaining fiber. To ensure the polarization of the input and output light in PM fiber, we use several different shapes of rods, and the resulting fibers are sold under trademarks such as “Panda” and “Bow-tie”.

Applications of Polarization Maintaining Fiber Patch Cable

Polarization maintaining fiber patch cable is also commonly used in telecommunications for the connection between source lasers and modulators. Because modulators require polarized light as input. Furthermore, it is used for special applications, such as quantum key distribution, interferometry and optical fiber sensing. But, they are rarely used for long haul transmission because Polarization Maintaining Fiber Patch Cable are more expensive and more attenuated than single-mode fibers.

Conclusion

In today’s optical fiber communication systems and applications, it’s necessary to understand polarization. And, it’s important to understand how to characterize and process polarization effects in order to maximize the performance of systems involving polarization sensitive devices. Polarization maintaining fiber patch cable is based on high-precision butt joint technology to maintain polarization. You can contact FS.COM, if you want to know more information.