Rami Arieli: "The Laser Adventure", Chapter 1:  Prism Applet
Prism Applet - Refraction and Dispersion
On the screen the prism have an apex angle (q) which is changeable.
As a source of light you can choose between:
  1. A laser which emit a narrow beam of single wavelength.
  2. A white light source which emit parallel beam.
The prism is made of transparent glass, and you can choose specific material from a list.
Since in normal glasses the differences between the values of the index of refraction for different wavelengths are small, we added (for educational purposes) an imaginary material, which have large differences in the index of refraction values for different wavelengths.
The beams of light are refracted according to Snell's law at the prism surfaces.

In certain conditions total internal reflection occurs.

If you want to see the real names of the prism materials, and the values of their index of refraction for different wavelengths, click here.


  1. Put the source of light on the right side of the prism by clicking with the left button of the mouse. The location of the mouse is the new location of the sourse.
  2. Mark the point on the prism where you want the beam to hit the surface by clicking with the right button of the mouse. As a result, a beam of light will be send from the sourse to the location you mark.
  3. You can change the apex angle of the prism with the slider.
  4. You can change the index of refraction of the medium from where the beam is coming to the prism.
  5. You can choose the material of the prism (from a list).
  6. You can choose the kind and color of the light source.


  1. Describe the differences of the results between different materials, for a specific apex angle, and explain the causes.
  2. Can you find a situation, for specific values of n1, that the beam will not pass to the other side of the prism, at any location of the light source?
  3. Within the simulation conditions, Is it possible for the beam to be reflected, and hit the light source? (Check your answer with the simulation).