Deviating prisms

Principle

The goal of this experiment is that the students become acquainted with special cases of the refraction of light at a prism which are important in technical applications (optical instrument construction). With the investigation and explanation of the light path as a function of the position of the prism in relation to the light source, knowledge about the laws of reflection and refraction, as well as total reflection, are strengthened. In the first part of the experiment, the normal refraction at a prism is investigated (as a revision exercise); whereas in the second and third parts of the experiment the possibility of employing a right-angled prism at 90° or 180° to reverse the incident light is recognised and understood.
It can also be recommended to take advantage of group work: each group investigates the path of light with a different position of the prism and, at the end of the experiment, the results and the conclusions are collected for a total result.

Benefits

• Multifunctional light box - All-in-one: Can be used for geometric optics on the table, colour mixing and on an optical bench
• Extension with others sets at anytime, no additional light sources needed, recognition value for students

Tasks

Not all prisms are the same. Investigate the course of a light beam on emergence from a right-angled prism when the light - falls at an angle to the hypotenuse - hits a cathetus at right angles - is incident to the hypotenuse at right angles.