Lesson: Terminating Optical Fiber With A Mechanical Splice Connector

Objectives: From this lesson you should learn:
How to use these tools to strip cable to the bare fiber

Tools:
Safety Glasses
Fiber Stripper
Kevlar Shears
Fiber Cleaver



Components:
Fiber optic cable
Connectors (several for practice)




Safety:

Always wear safety glasses when doing any of these exercises and dispose of all fiber scraps properly. Safety Rules - Read before beginning any exercises.

Exercise

Before attempting this exercise, you should complete the exercises on stripping and cleaving fibers.

1: Examine the mechanical splice connector. The connector has a short fiber cemented into the ceramic ferrule and polished in a factory. Behind the ferrule is a mechanical splice ready to use and a connector body that can clamp onto a 900 micron buffered optical fiber and/or 3mm jacketed cable.



The installation process involves preparing a fiber, inserting the fiber in the splice section of the connector, inserting it until it butts up against the connector fiber to create a splice, then closing the connector body clamping the fiber (and cable if terminating a jacketed cable.) Finish the connector by screwing on the locking nut.

A VFL can be used to verify the splicing process as you can see below. Insert the connector of your cut patchcord in the VFL and turn the VFL on. The light from the end of the fiber will help you see the small hole on the end of the connector where you must insert the fiber and it will help you verify the splice in the connector has been made properly as you can see in the video below.



We'll use this mechanical splice connector to terminate the bare fiber end of your cable in this exercise, first with 900 micron buffered fiber then with a 3mm jacket cable.

First with 900 micron buffered fiber

1. Slip the locking nut on the cable's cut end. Makes certain it is in the correct direction.

2. Use the fiber stripper to cut off 4" (100mm) of the cable jacket and pull off the cut piece.

3. Use the kevlar scissors to cut the aramid fiber strength members at the end of the jacket, exposing the 900micron tight buffered fiber.

4. Use the fiber strippers to strip ~1.5" (40mm) from the end of the fiber in 4-6 steps, about 1/4-3/8" (6-8mm) at a time.
 
5. Clean the fiber with a lint-free wipe and alcohol.



6. Cleave the fiber to a length of 16mm from the end of the 900 micron buffer using the cleaver's stripping gage.

Clean up all your fiber scraps immediately after cleaving the fiber and dispose of them in a container like a used take-out coffee cup marked "Fiber Scraps"!
 
7. Insert the fiber into one end of the splice on the connector until it stops and verify the splice is properly made with the VFL - the light from the splice should be minimized and the protective cap on the connector should light up brightly - see the photo above showing termination with the VFL. You can pull the fiber back slightly and push it back in, rotating it slightly, if needed to get a good splice. Then push down the plastic crimp lever on the connector to hold that fiber. Screw on the plastic nut to lock the fiber in place.

Watch this to see how it's done:



8. Practice this exercise several times with the connectors supplied. Be sure to keep several connectors if you need to do demonstrations to your instructor.


10. Terminating 3mm Cable
Terminating 3mm cable is similar to the 900 micron fiber steps above. The difference is how the cable is prepared. The length of 900micron buffered fiber beyond the jacket and the length of aramid fiber need to be different. See the stripping diagram below:


Insert the fiber into the connector and watch the VFL light to ensure a good splice. Close the fiber clamp on the cable and secure with the locking nut.


You have successfully completed this exercise when you have made several connectors that show low splice loss and good light through the connector.



After successfully terminating fiber with the connector several times, fill in your Scorecard.



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This information is provided by The Fiber Optic Association, Inc. as a benefit to those interested in teaching, designing, manufacturing, selling, installing or using fiber optic communications systems or networks. It is intended to be used as an overview and/or basic guidelines and in no way should be considered to be complete or comprehensive. These guidelines are strictly the opinion of the FOA and the reader is expected to use them as a basis for learning, as a reference and for creating their own documentation, project specifications, etc. Those working with fiber optics in the classroom, laboratory or field should follow all safety rules carefully. The FOA assumes no liability for the use of any of this material.