To demonstrate a retroreflector.
- 3 Mirror corner
- Class I or II Laser
- Smoke Machine
3 Mirror Corner Setup.
The three mirrors arranged to have three mutually perpendicular faces have the property of being retrodirective; i.e. it will reflect all incoming rays back along their original directions. When viewed from any angle the image of the observer always appears at the vertex of the three mirrors. Alternatively a laser beam directed to the reflector comes straight back. A cloud of smoke makes the beams visible to the class.