Homemade fibre optics
Lasers and fibre-optics are often used to cause beautiful decorative effects but are also important in many fields of science, including medicine and communications. In this experiment you will make a simple fibre-optic device capable of bending light.
You will need:
- A baking tray
- Some petroleum jelly (vaseline)
- Some water
- A syringe or water dropper
- A cotton bud or piece of cotton wool
- A small torch or better still a hand held laser
And last but not least ... a helping hand from an adult.
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Method
First you must cover the baking tray with a thin layer of petroleum jelly – smear it with your finger.
Then, using a piece of cotton wool or a cotton bud, draw a pattern on the tray by wiping off the petroleum jelly. The drawing should be in one continuous line. MAKE SURE that the drawing does not involve any sharp angles but only gently curving lines.
Using the syringe or water dropper, add water to the tray along this drawn pattern. The petroleum jelly should prevent the water from running outside the lines drawn by the cotton tip.
Switch off the lights and touch the torch light or laser light against the end of the water line.
Light should travel along the line of water by means of total internal reflection pretty much as it travels along glass fibreoptics.