In this resource students will carry out experiments with prisms, polarising film and 3D cinema glasses to explain some of the interesting properties of light and their applications.

Light from light bulbs allows us to see at night, light from the sun provides plants with energy and light from a computer screen lets you to surf the internet. But there are many more properties of light that people make use of than just the ability to provide us with sight and energy.

This activity should take approximately 1 hour, however allow more time if you are going to complete the extensions.

The activity

What you need

  • Ray box
  • Two pieces of polarising film
  • Two transparent triangular prisms
  • Pairs of realD 3D cinema glasses

The tasks

  • Dispersion - Start off with a discussion about rainbows and to lead into a discussion of the fact that white light is made up of different colours. Depending on the age of the students, you could discuss wavelengths/frequency.
    • Explanation - This experiment uses the idea that light of different colours (wavelengths) refracts by different amounts.
    • Some maths - The refractive index is a measure of how much a medium will “bend” light.
    • Some extras - Students can experiment with the refraction by using different angles of incidence and see if they can generate total internal reflection. 
  • Polarisation
    • Some extras - The students experiment with two pieces of polarising fil.
    • 3D cinema makes use of polarisation of light to create its 3D effect. If students are at the correct level, they could finish this activity by researching how 3D cinema works and how polarisation comes into it.

Engineering is ...

The image of an engineer that students often have in their heads is one of a person (normally a man) working in a hard hat.

Engineering is so much more than that. Engineering is the designing, testing, manufacturing and improving of products to do something useful. It is the application of science, maths and creative skills to achieve a goal.

Photonics engineers create and improve systems and products that use light to function. The main purpose of the photonics engineering field is to develop new and innovative products for the medical field, telecommunications, manufacturing, and construction.

From light that can cut plastic, to ultra-accurate lasers used in delicate eye surgeries, photonics engineers are responsible for some very big scientific leaps and bounds.