The interactive animation shows how a light beam is reflected and refracted on a semi-transparent surface (Snell’s law of refraction).
Instructions for Use
As with all animations, the windows can be enlarged or reduced by clicking on them.
After starting the application, you can view the animation in full-screen mode. To do this, click on “View” and then on “Full screen”:
To exit full screen mode, press the Esc key.
Description of the Animation
To change the angle of incidence of the light beam, click on the top of the spotlight and move the mouse to the left or right.
Alternatively, you can also change the target point of the light beam.
To do this, move the point at the bottom of the animation.
This animation also allows curved surfaces to be displayed. Change the shape of the surface using the points on the right and left edges of the animation.
The refractive index of the medium can be set between 1 and 10.
The maximum refractive index observed in a naturally occurring material is 2.42. This value belongs to diamond. Materials produced in laboratories can reach higher refractive indices. Experiments have produced artificial materials with refractive indices of over 4. Such high-performance materials are often developed for specialized applications such as optical lenses, lasers and other optical devices.
Physical Background
Snell’s law of refraction describes how a light beam behaves at the boundary between two media:
\[ n_1 \cdot \sin(\alpha_1) = n_2 \cdot \sin(\alpha_2) \]
- n₁, n₂: Refractive indices of the two media
- α₁: Angle of incidence (measured from the normal to the surface)
- α₂: Angle of refraction
The law of reflection also applies: the angle of incidence equals the angle of reflection.
To view the formulas in the animation, click on the content window of the animation.
Overview and Download
| Title | Snell’s Law of Refraction |
| Target Audience | Teachers and Lecturers |
| Platforms | Microsoft® Windows® Apple® Macintosh® (version-dependent) |
| Features | Full-screen mode Lossless scaling Large screens and projectors supported |
| License | Freeware |
| Download | Contact |
Didactic Idea
The scene shown can be partially simulated with an experimental setup. The advantage of the animation is that the geometric relationships can be quickly clarified.
Source information
Authoring tool: Adobe Animate (Note: This software can now only be used to a limited extent for modern animations.)