Rami Arieli: "The Laser Adventure", Ruler Lab., Page 1
Interference experiment using a Ruler

This experiment was first demonstrated by A. L. Schawlow(1).
In this experiment you measure the laser wavelength with a simple ruler (!)
Schawlow is the scientist who received the Nobel price for the invention of the idea of the laser.

Objective: To calculate the wavelength of laser light using a simple ruler as a diffraction grating.

Theory: In this interference experiment, a simple ruler will serve as a grating.

The experimental set up is shown in Figure 1:

Figure 1: The experimental setup.