IGCSE Physics / Light waves

Total internal reflection in optical fibres and prisms

Edexcel International GCSE Physics (4PH1), chapter 12: Light waves, specification point 3.20. Part of the full course.

Read the revision notes · IGCSE Physics past papers

Optical fibres and prisms guide light by total internal reflection. This lets fibres carry signals or images, and lets prisms turn light through 90° or 180°.

More lessons in Light waves

• Reflection of light and plane mirrors
• Refraction of light
• Practical: refraction in blocks and prisms
• Refractive index: n = sin i / sin r
• Practical: measuring the refractive index of glass
• Critical angle and total internal reflection