You will need:
Scribe
Polishing film (pink 12 micron, yellow 3 micron, and white 0.3 micron)
Glass polishing plate (and rubber pad for physical contact connectors (mostly singlemode)
Polishing Puck
Notice we are showing polishing on a glass surface, which is hard and flat. This works well for flat ferrules like most multimode ferrules. But some multimode and all singlemode ferrules are radiused - for a "PC" or "physical contact" finish. These should be polished on a soft surface like a rubber mat. (SM connectors are also wet-polished on diamond film to polish the fiber and ferrule together into a smooth end finish.) Here are the full instructions for singlemode polishing.
You can use a soft polish with multimode ferrules too, and get a slightly better finish, but it will take a bit longer to polish.
Contents
Step 1 - Getting Ready
Step 2 - Examine Connector Construction
Step 3 - Stripping the Cable
Step 4 - Preparing the Epoxy
Step 5 - Applying the Connector to the Fiber
Step 7 - Visual inspection - microscope
Step 8 - Test the Connector
Step 9 - The Quiz
Once the epoxy has cured, you are ready to scribe and remove the excess glass and epoxy from the tip.
A preliminary step is to apply sheets of 3 and 0.3 micron lapping film to the polishing glass as shown below. If you are polishing PC (physical contact - or convex) ferrules, use a rubber pad between the polishing film and the glass plate.
The next step is to "cleave" the stub of glass protruding from the ferrule. Take the connector in one hand and the scribe in the other. Holding the scribe very lightly, delicately give the glass 3 scratches at the point where it protrudes from the epoxy bead on the ferrule.
Lay the scribe aside, and grasp the glass. Carefully pull up and away from the scribe. The glass should break cleanly at the scribe point, but there will be a little bit left at the tip and it may be sharp! Discard the glass fiber fragment in the fiber disposal bin!
"AIr Polish" the fiber stub first with 12 micron film, holding it as shown. Polish the tip lightly for 10 to 20 seconds. Notice the change in sound (quieter) as the burr gets filed down and the epoxy bead is removed. Remember to brush the tip lightly and do not overpolish.
Visually inspect the tip. There should be some epoxy left, and the glass itself will be not be smooth.
Clean the tip with an Alco pad to remove any loose grit or epoxy.
Now prepare to use the polishing puck with the polishing plate. Always hold the puck up in your hand and then insert the connector. Never insert the connector into the puck while it is lying on the glass because you may chip the glass at the ferrule tip.
Gently place the puck with the connector in it on the yellow film which is on the polishing glass. Remember the tip is a ragged glass end which can be easily damaged.
Very lightly make 4 or 5 figure eights as you polish the tip. You'll actually feel a smoothing of the surface as the epoxy scrapes off and the ceramic surface of the ferrule meets the surface of the abrasive. Do not overpolish the tip. Remember, the glass is softer than the polishing abrasives. Overpolishing can cause the glass to be undercut, and this will cause excess light loss at the connection.
Stop as soon as the connector feels "slick"! The polishing film and the ferrule are made of similar materials. As soon as all the epoxy and protruding fiber is removed, the ferrule will be rubbing against the film and it will feel like the puck is floating on air.
Clean the tip with an Alco pad and inspect it to see that all the epoxy is gone. If not, give it 1 or 2 more figure eights on the yellow 3 micron film to remove it. Remember -do not overpolish!
Very gently lay the puck on the 0.3 micron film. With almost no pressure, make about six figure eight strokes.
Remove the tip from the puck, and clean it with an Alco pad.
The connection is now complete, ready for visual inspection of the tip.
