Figure 1: Setup for Interferometer

Materials:

• Laser
• Movable Mirror
• Adjustable Mirror with Micrometer
• Beam Splitter
• Viewing Screen

Demo:

The setup for the experiment is shown in Figure 1. Light from a laser shines into a beamsplitter, producing two resultant beams of light. The beams are then brought back together using two mirrors. When the resultant beams combine, they interfere, producing a series of light and dark rings on a screen.

Explanation:

The Michelson interferometer separates the light into two beams before recombining them. Following the interference theory, since light can act as a wave, then the two beams of light resulting from the beamsplitter would then recombine differently, depending on whether constructive or destructive interference is at play.

If two light waves are in phase with each other, then recombining them would make the amplitude of each wave add, demonstrating constructive interference and creating the bright rings. On the other hand, if the two light waves are out of phase with each other, then destructive interference occurs such that the two light waves cancel each other out, thus creating the dark rings on the screen.