Purpose:Show the interference of sodium yellow light with a Michelson interferometer.
Description:This experiment uses a large sodium source with the Michelson interferometer to produce fringes. The pattern is not bright enough to project, so it is displayed for the class using TV. With the two optical paths very nearly equal, the two yellow lines are in phase and the interference pattern has very good definition. Adjust the moving mirror so that the path lengths are not equal to obtain less contrast in the pattern.
This demonstration is very sensitive to alignment and temperature, and is not recommended for routine classroom use.