DIY: Optical fiber illumination

Optical fibers are hair-thin strands of glass, silica or plastic that transmit light from a point to another with very little loss, which is why they are used to transmit high-bandwidth data over long distances or in sensors, illumination and toys.

We are going to show you how to connect optical fibers directly to LEDs and sensors, to use it with illumination purposes or “light painting pictures”, following the steps written by Forrest M. Mims III, amateur scientist, in Make Magazine.

You will need:

• 5mm LEDs encapsulated in epoxy packages
• Sharpie market
• An optical fiber cable
• A hobby knife
• 200 and 400 grit sandpaper
• A heat-shrink tube
• Heat gun
• A binder clip and a clothes-pin
• Drill
• Compressed air
• Plastic adhesive

Step 1: Prepare the fibers’ ends. Place the fiber in a flat wood surface and slice off a few millimeters using the hobby knife to cut straight down the fiber.

Step 2: Place the 200 grit sandpaper in the flat surface and press the fiber end against it, making approximately 12 circles. Repeat this procedure with the 400 grit sandpaper.

Step 3: Slip 1” of tubing over the LED and warm it with a heat gun until the LED is held perfectly in place.

Step 4: Slip the prepared end of the fiber into the open end of the tubing and keep warming. Depending on diameter of the tubing, the fiber could stay in place or pushed in and out of it. You can keep it in place by applying adhesive.

And the joining is done. But in case you want to make a more permanent connection, you should:

1. Hold the leads of the LED using a clothes-pin and a large binder clip.
2. Use the Sharpie to draw a plus sign over the end of the LED, place the drill in the center of the plus sign and guide it into the device applying gently pressure.
3. Remove any left overs using compressed air. And make sure the LED leads keep undamaged.
4. Insert the prepared end of the fiber into the hole, secure it in place with a plastic adhesive and let it dry.
5. Insert what you consider is a suitable length of heat-shrink tubing over the LED and the fiber, then warm it with the heat gun. 

Now it’s time to have fun and illuminate your projects with your connected fibers!

With information and pictures from Make Magazine.