Have You Remembered to Clean Your Fiber Optic Connectors?

Needless to say, keeping the cleanness of fiber optic connectors is essential to the high performance of optical devices. If the ferrule is damaged or broken, the whole connector will be useless. Therefore, protecting the connector ferrule from any possible contamination is very necessary. You need to take fiber optic cleaning seriously as a routine work to avoid extra loss.

Types of Contaminants

From the following picture, it is clear to see that the end face of a fiber consists three areas: ferrule, cladding and core. Once these parts are free from contamination, fiber optic cleaning is complete. Different contaminants may result in different cleaning solutions. Do you know how many kinds of contaminants are there on the fiber optic connectors?

fiber end face

Generally speaking, there are three types of contaminants. Dusts and oils are the most common types. Cleaning these contaminants is easier as long as using the proper method. However, the contaminant of scratches, chips or pits sometimes may cause permanent defects on the end face. Then a new connector is required for replacement. Oils from your fingers will leave a noticeable defect easily seen with the use of a fiber scope, but it will also tend to trap dust against the fiber, which can lead to scratches on both the fiber connector and the optic it is being mated to. In addition, when installing or removing a fiber, small static charge on the ends will attract dust particles in the air. Therefore, putting on the fiber caps is a good precaution if the cable is not used.

end face contamination

Several Cleaning Methods

Nevertheless, if the connector is already polluted, using fiber caps will no longer be enough. Proper cleaning methods should be applied to remove the contaminants. Here lists some common cleaning methods:

  • Dry cleaning – No solvent is used for this type of method. The whole cleaning is processed in a dry condition.
  • Wet cleaning – Solvent is required for this method. Isopropyl alcohol is the most common solvent.
  • Non-abrasive cleaning – This method will not use any abrasive material to contact the connector end face.
  • Abrasive cleaning – This method will adopt abrasive tools such as lint-free wipes to do the cleaning.
Solutions for Fiber Optic Cleaning

If you have decided the cleaning method, then it is time to choose the right cleaning products. Common cleaning solutions on the market now are the pen cleaner, cassette cleaner, cleaning card and wipes.

Pen Cleaner

Pen cleaner is also named as one-push cleaner. It features an easy one push action, which quickly and effectively cleans the end-face of connectors. The cleaning tip is rotated to ensure the fiber end-face is effectively but gently cleaned. Usually available for 600 to 800 cleans.

pen cleaner for cleaning fiber optic connectors

Cassette Cleaner

Cassette cleaner or reel-type cleaner is ideal for lab, assembly line and field use. It enables simple push bottom shutter operation for quick and easy cleaning. Each cleaning tape is available for 400 to 500 cleans.

cassette cleaner

Cleaning Card & Wipes

Cleaning card is made of the densely woven micro fiber cloth which effectively minimizes the static charge. Wipes are designed with minimal lint or dust to have little interference with the normal functioning of the equipment.

wipes and cleaning card

Common Cleaning Procedure

Follow these steps, you can always make a thorough fiber optic cleaning:

  • Step 1, inspect the fiber connector with a fiber scope.
  • Step 2, if the connector is dirty, clean it with a dry cleaning technique.
  • Step 3, inspect the connector.
  • Step 4, if the connector is still dirty, repeat the dry cleaning technique.
  • Step 5, inspect the connector.
  • Step 6, if the connector is still dirty, clean it with a wet cleaning technique followed immediately with a dry clean in order to ensure no residue is left on the end face.
  • Step 7, inspect the connector again.
  • Step 8, if the contaminant still cannot be removed, repeat the cleaning procedure until the end face is clean.
Conclusion

Constantly cleaning the fiber optic connectors can greatly decrease the link failures and unnecessary component replacement. Moreover, using professional tools is much safer and cleaner. Are you ready to clean the fiber optic connectors from now on?

How Does Fiber Connector Polish Type Influence Termination?

Connectors are used to mate two fibers to create a temporary joint and/or connect the fiber to a piece of network device. That’s one of fiber termination ways. The primary specification of connector termination is loss or the amount of light lost in the connection. Connector loss can be caused by a number of factors. This article will talk about the influence of fiber connector polish type on connector termination.

fiber-connector-termination

When the cone of light emerges from the connector, it will spill over the core of the receiving fiber and be lost. In addition, the end gaps can arouse the other problem called reflectance. The air gap in the joint between the fibers causes a reflection when the light encounters the change of refractive index from the glass fiber to the air in the gap. This reflection is called to as reflectance or optical return loss, which can be a problem in laser based systems.

Nowadays the fiber optic connectors have several different ferrule shapes or finishes, usually referred to as end finish or polish types. The connector end face preparation will determine the connectors’ return loss, also known as back reflection. Different end face causes different back reflection.

PC Polish

The Physical Contact (PC) polish results in a slightly curved connector surface, forcing the fiber ends of mating connector pairs into physical contact with each other. This eliminates the fiber-to-air interface and results in back reflections of -30 to -40 dB. The PC polish is the most popular connector end face, used in most applications.

UPC Polish

In the Ultra PC (UPC) polish, an extended polishing cycle enhances the surface quality of the connector, resulting in back reflections of -40 to -55 dB and < -55dB, respectively. These polish types are used in high-speed, digital fiber optic transmission systems.

APC Polish

Later, it was determined that polishing the connector ferrules to a convex end face would produce an even better connection. The convex ferrule guaranteed the fiber cores were in contact. Losses were under 0.3dB and reflectance -40 dB or better. This solution is to angle the end of the ferrule 8 degrees to create APC or angled PC connector. Then any reflected light is at an angle that is absorbed in the cladding of the fiber, resulting in reflectance  of >-60 dB.

FC-APC-Connector

As the introduction of fiber optic technology, numerous connector styles have been developed – probably over 100 designs. Each connector style is designed to offer better performance (less light loss and reflectance) and easier, faster and/or more inexpensive termination. For example, FC–“Ferrule Connector”. The following are three common types of FC connectors:

  • FC/PC–It’s the most common of the FC connectors. The tip is slightly curved to ensure only the fiber cores make connection during mating not the ferrules themselves. The return loss is 25-40 dB.
  • FC/UPC–The higher quality polish with rounder edges than FC/PC ensures better core mating. The return loss is 45-50 dB. It can mate with FC/PC connectors.
  • FC/APC–Common in most single mode applications where back reflection is critical to be minimized. Identified by the 8 degree of angle present in the ferrule tip along with a typical green colored strain relief boot. The return loss is 55-70 dB. It can only mate with other FC/APC fibers.

From this article, you can see the connector with APC polish type can provide the best connection. Later when you face many different types of fiber optic connectors, you may take polish type as one of the factors to make your decision.

Article source: http://www.china-cable-suppliers.com/how-does-fiber-connector-polish-type-influence-termination.html