Rami Arieli: "The Laser Adventure" Chapter 10 Section 0, page 4
Michelson Interferometer
In the 20th of the twentieth century, Michelson invented the Interferometer which is based on the interference of two waves coming from the same origin.
Michelson received the Nobel price in 1907.
Today, the interferometer is one of the most accurate measuring instrument in use.

Michelson interferometer is an instrument which use interference between two beams of electromagnetic radiation, which are created by common origin.

In Michelson interferometer, like the Young interference experiment, a parallel beam of light is split by a beam splitter into two beams, as can be seen in figure 10.1.

 
Figure 10.1: Michelson Interferometer
 
On the screen an interference pattern is seen, if the optical path difference between the two beams is less than the coherence length of the laser (as explained in the following pages).