Draw a diagram to show how light is transmitted along an optical fibre. - Leaving Cert Physics - Question 1 - 2021

To illustrate how light is transmitted along an optical fibre, follow these steps:

1. Draw the Optical Fibre: Start by sketching a long, thin cylinder that represents the optical fibre. The fibre should have a core, which is the inner part, and a cladding layer that surrounds it.

2. Label the Components: Clearly label the inner section as 'Core' and the outer section as 'Cladding'. Show that the core has a higher refractive index compared to the cladding.

3. Depict Light Rays: Draw lines (light rays) entering the core at an angle. Make sure to represent multiple rays to demonstrate the process effectively.

4. Show Internal Reflections: As the light rays travel through the core, depict them reflecting at the boundary between the core and cladding. Ensure that these reflections are at angles greater than the critical angle, which allows total internal reflection.

5. Indicate Direction of Travel: Use arrows along the light rays to indicate the direction in which the light is traveling.

6. Final Touches: Highlight that the light continues to travel through the fibre due to these internal reflections, leading to the conclusion that the fibre can transmit light over long distances without significant loss.