FOA Basic Skills

Lesson: Splicing Optical Fiber With A Mechanical Splice

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

Safety Glasses
Fiber Stripper
Kevlar Shears
Fiber Cleaver

Tools for stripping fiber optic cable

Fiber optic cable
Splices (several for practice)



Lennie works safely

Always wear safety glasses when doing any of these exercises and dispose of all fiber scraps properly.

Safety Rules - Read before beginning any exercises.


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

Examine the mechanical splice. The splice has a sleeve inside that aligns the fibers to create a splice. The installation process involves preparing a fiber, inserting the fiber in the splice, crimping that end, then preparing a second fiber, inserting it until it butts up against the first fiber to create a splice, then crimping the second fiber.
Finish the splice by pushing the crimp section down fully.

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 splice where you must insert the fiber and it will help you verify the splice has been made properly.

mechanical splice

We'll use this mechanical splice to splice two pieces of your cable back together in this exercise.

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 fibers 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.

Cleave length

6. Cleave the fiber to a length of 15mm 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 until it stops, then push down the plastic crimp on the end to hold that fiber. Be sure to only push the crimp at the very end so you do not crimp both ends - that will make it impossible to insert the second fiber.

8. Repeat with the second fiber - strip/clean/cleave - then insert the fiber in the other end of the splice. Watch the VFL light to see how the light increases out of the fiber as the splice joint is made. When you get the brightest light, crimp the second fiber, then push the crimp down fully.

Watch this to see how it's done:


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

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

After successfully splicing fiber several times, fill in your Scorecard.

Learn the "splicers mantra" - "strip - clean - cleave - splice"

Return to Lesson Plan

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.


Table of Contents: The FOA Reference Guide To Fiber Optics

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